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Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992 (1999)

Chapter: EPACT Committee Review of Completed Projects

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Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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EPACT COMMITTEE REVIEW OF COMPLETED PROJECTS

DOE Engineering Projects

The present EPACT Committee received 11 of 12 engineering reports funded by EMF-RAPID as contracts in time for inclusion in the committee's final report. The 11 engineering reports are listed in table 1.

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

Table 1—EMF-RAPID Funded Engineering Projects Reviewed by EPACT Committee

#

Organization

Title

Work Done

1

Electric Research & Management, Inc.

"Development of Recommendations for Guidelines for Field Source Measurement"

Identification of set of MF characteristics that can be measured; development of protocols for measurements of fields from appliances on a laboratory test rig and from on-site measurements in complex field environment;

gathering of data for specific appliances and environments

2

Magnetic Measurements Co.

"Recommendations for Guidelines for Environment-Specific Magnetic Field Measurements"

Identification of set of MF characteristics that can be measured; development of protocols for characterizing human activity patterns and using information to estimate personal exposures in defined areas; application of protocol in pilot studies

3

Enertech Consultants

"Environmental Field Surveys"

Surveys of MF levels in various environments

4

T. Dan Bracken, Inc.

"Recommendation for Guidelines for EMF Personal Exposure Measurement"

Identification of set of MF characteristics that can be measured; development of measurement protocols

5

T. Dan Bracken, Inc.

"Development of an EMF Measurements Database"

Development of database to serve as repository for MF exposure data

6

Enertech Consultants, Inc.

"Survey of Personal Magnetic Field Exposure"

Survey of average field exposures of 1000 randomly selected people in the United States

7

National Institute for Occupational Safety and Health

"Hazard Surveillance for Workplace Magnetic Fields"

"Walkaround" surveys of MF characteristics in large number of workplace environments

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

#

Organization

Title

Work Done

8

IIT Research Institute and Commonwealth Associates

"Evaluation of Field-Reduction Technologies"

Evaluation of field-reduction strategies for several kinds of sources, including cost estimates for various strategies for each kind of source

9

University of Washington

"Characterization of Exposures to Extremely Low Frequency Magnetic Fields in the Office Environment"

Spot and personal exposure-meter measurements of MFs in office environments and homes

10

EM Factors

"Assessment of Human Exposure to Magnetic Fields Produced by Domestic Appliances"

Comparison of information from questionnaires with data gathered from personal exposure meters for a group of 40 women in England to determine degree of correlation

11

Center for Risk Management, Resources for the Future

"Risk Dimensions of the EMF Problem"

Views of author on nature of power-frequency magnetic field risk [Note: although funded through the EMF-RAPID engineering program, this project did not involve actual engineering research]

12

T. Dan Bracken, Inc.

"Source and Exposure Prediction Model Development"

Project not completed in time for committee review

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

Committee evaluations of the projects follow:

Project 1: "Development of Recommendations for Guidelines for Field Source Measurement" (Electric Research and Management, Inc).

This project (ERMI 1997) involved identifying the set of field characteristics that should be measured for interpreting the results of biologic and human-exposure studies and for focusing any future attempts at field management. The investigators also proposed methods for characterizing MF sources on the basis of MF strength at a fixed distance, dominant field components, intermittency, spatial attenuation, and polarization. In addition, the report describes protocols for measurements of fields from appliances and for on-site measurements of fields in a complex exposure environment, such as an office or factory. Examples of these measurement protocols were provided, and useful data were presented on the MFs measured in the vicinity of 20 appliances commonly used in homes and offices.

Project 2: "Recommendations for Guidelines for Environment-Specific Magnetic-Field Measurements" (Magnetic Measurements Co).

This study (Magnetic Measurements 1998) attempted to anticipate every aspect of power-frequency MFs that might be related to biologic or human health effects and suggested the equipment, measurement protocols, data-management and analysis procedures, quality-control measures, and reporting procedures that should be used for characterizing the MF environment in any given occupational, public, or residential setting. Methods are described for characterizing human activity patterns and for using that information to estimate personal exposures to sources in a well-defined area. For that purpose, each study area is to be divided into sharply defined microenvironments within which the fields and activity patterns can be characterized with reasonable precision. The protocol was tested in three pilot studies involving a day-care center, a metal fabrication plant, and a grocery store. The field-characterization procedures described in the report would be extremely difficult and expensive to perform on a large number of people in any specific occupational or public environment. In addition, the results of other studies have not shown a clear correlation between activity patterns and MF exposure from appliances (see report of project 10).

Project 3: "Environmental Field Surveys" (Enertech Consultants)

The objective of this project (Enertech Consultants 1996) was to perform preliminary surveys of the levels and characteristics of MF exposures in residential, public, and occupational environments. Measurements were made of time-weighted average 60-Hz MFs and harmonic fields in grocery stores, schools, office buildings, hospitals, and machine shops. For each type of environment, four sites were studied; 11 sites were in California, and nine were in Massachusetts. Area surveys of the MFs indicated an approximately three-fold variation in the average exposure levels in the five types of environment; the measured values being 0.193 microtesla (µT) in grocery stores, 0.142 µT in machine shops, 0.127 µT in hospitals, 0.083 µT in schools, and 0.072 µT in office buildings. The highest occupational exposures were found for welders in machine shops (0.52 µT), butchers in grocery stores (0.41 µT), and clerks and cashiers in grocery stores (0.40 µT). Exposures were about the same for students, visitors in hospitals, and

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

professionals in office buildings—all 0.08–0.09 µT. The main sources of area fields were found to be net electrical currents in wiring, office equipment, milling and welding equipment, fluorescent lights, electrical panels in machine shops, and powerlines. It also was observed that DC and AC fields generally are not aligned (either parallel or perpendicular) to each other, third and fifth harmonics of MFs from various sources are generally the largest (with amplitudes that are, respectively, about 30% and 10% of the 60-Hz primary field amplitude), and the polarization of MFs is generally random. Funding limitations, and the unwillingness of people at some sites to participate reduced the type and number of sites surveyed. Apparently because of an agreement with site-owners and operators not to identify the sites, there is a minimal description of the sites. For example, there is no indication of whether the facilities were modern or old, and no information on the types of hospitals or office buildings.

Project 4: "Recommendations for Guidelines for EMF Personal Exposure Measurement" (T. Dan Bracken, Inc).

The report on this project (T. Dan Bracken 1997a) described protocols for an exhaustive assessment of personal exposures to power-frequency fields. An extensive discussion is given of potentially relevant field parameters, measurement equipment, technical problems associated with MF measurements, measurement protocols, time-activity monitoring, data management and analysis, and quality control. The report recommends that MF measurements record the resultant field (the square root of the sum of the squares of three orthogonal field components) rather than the magnitude of the field (which includes phase information but is more difficult to measure). For EFs, the investigators regard measurements at the body surface as having reasonable precision, but they recognize that the magnitude of a field depends in a complex manner on the orientation of the subject relative to the source of the field. The report also discusses the onerous and expensive nature of time-activity recording in diaries carried by the study participants. Some limited pilot results were obtained by using high-school physics students and employees at an instrument-manufacturing facility as subjects, but there were not enough data to assess the value of time-activity recording.

Project 5: "Development of an EMF Measurements Database" (T. Dan Bracken, Inc).

This project (T. Dan Bracken 1997b) involved the development of an MF measurements database that can serve as a repository for data and reports generated in a wide variety of studies on this subject. An Internet site was established to make the data readily available to users. Three types of data can be entered into the database: a "metadata" file that describes the origin, development, and physical content of a data set, a "data products" information base that contains actual measurement data and a "reports information" base that contains the text, tables, and figures describing the results of a study. The functions of the MF database were illustrated by entering a small set of data on 20 persons, 18 of whom were federal office workers. Although the report clearly describes the procedures for recording MF exposure data and making them available to users, there have apparently been no efforts to use the procedures for archiving the data obtained in large surveys of personal MF exposure, such as project 6, below. There is no information as to how much the database has been used, how satisfied any users are, and whether any problems have been encountered in its use.

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

Project No. 6: "Survey of Personal Magnetic Field Exposure" (Enertech Consultants)

The goal of this project (Enertech Consultants 1998a,b), which was the most comprehensive study undertaken as part of the EMF-RAPID engineering program, was to analyze average exposures to power-frequency MFs (and harmonics up to 1,000 Hz) of the US population on the basis of a randomly selected cross section of 1,000 people. The study used a combination of information obtained by questionnaires and by 24-h continuous measurements recorded with a compact MF exposure meter (the EMDEX). Exposures of people in all the major geographic regions of the United States at home, work and school and during travel were measured using a study design that was balanced on the basis of the gender and age of the participants. Before the main study, a pilot study (phase I) was performed with about 200 participants. The results of the phase I study formed the basis of a number of important decisions on the phase II study protocol and the personal exposure meter to be used (the EMDEX-MATE with permanent memory and 10-min data summaries). The primary findings of the large phase II study with approximately 1,000 participants were:

  • The geometric mean value (and 95% confidence interval) recorded for a 24-h exposure is 0.089 (0.085–0.093) µT, with a lognormal distribution of data over the range 0.03–0.30 µT. Percentages of the population exposed to 24-h average field levels greater than 0.2, 0.3, 0.5, and 1.0 µT are 14.3%, 6.3%, 2.4%, and 0.5%, respectively. Those percentages are higher by about 35% than those observed in the previous Electric Power Research Institute 1,000-home study, in which "spot measurements" of MF levels were taken in various rooms of the homes (usually at the center of a room). It is reasonable that the personal exposure meters used in the present study would give higher average exposure levels in that the people wearing the exposure meters often came into contact with or were close to appliances that generated relatively large power-frequency MFs. It should be noted that 24-h exposure includes occupational exposures, which can be higher than residential ones.

  • Little difference was observed in MF exposure between men and women, and the highest exposure was of working-age people (0.097 µT), followed by retirees and preschool children (0.080 µT) and school-age children (0.076 µT).

  • Little geographic dependence was found in the average MF exposure, with the largest geometric mean value being observed in the Northeast (0.100 µT), followed by the West and Midwest (0.087 µT) and the South (0.086 µT).

  • About 25% and 9% of the population were exposed to fields greater than 0.4 µT and 0.8 µT, respectively, for more than 1 h per day.

  • About 1.6% of the population were exposed to fields greater than 100 µT at least once in a 24-h period.

  • The highest average exposure occurred "at work" (0.103 µT), followed by "on travel" (0.096 µT), "at home not in bed" (0.080 µT), "at school" (0.064 µT), and "at home in bed'' (0.052 µT). The average field exceeded 0.2 µT for 21%, 14%, and 3.5% of the people in the categories "at work", "at home not in bed", and "at school", respectively.

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×
  • For the "at work" period (8 h averages), the highest exposures were among electrical workers (0.16 µT), followed by food, cleaning, health, and protective service workers (0.16 µT), technical, sales, and administrative workers (0.11 µT), management and professional specialty workers (0.10 µT), precision production, crafts, equipment-repair workers, operators, fabricators, and laborers (0.09 µT), and farming, forestry, and fishing workers (0.05 µT).

  • For the "at home" period, the highest average exposures were experienced by people living in standard (fewer than 5 floors) apartment buildings (0.11 µT) and duplexes (0.10 µT), followed by tall (more than 5 floors) apartment buildings (0.09 µT), single-family homes (0.07 µT), and mobile homes (0.05 µT). The highest average exposures were in small (less than 1,000 ft2) dwellings (0.08 µT), followed by medium (1,000–2,000 ft2) dwellings (0.07 µT), and large (more than 2,000 ft2) dwellings (0.06 µT). Bedroom exposures were greatest when the bedroom was on the second or higher floors (0.06 µT), followed by the first floor (0.05 µT) and the basement (0.05 µT). Higher average exposures were observed in dwellings with metal pipes (0.08 µT) than with plastic pipes (0.05 µT).

  • "At home" average exposures were inversely related to the distance of the nearest overhead powerline (less than 25 ft, 0.09 µT; 25–50 it, 0.08 µT; 50–150 ft, 0.06 µT; and more than 150 ft, 0.06 µT). Exposure also varied with the type and number of powerlines; the highest exposures were associated with transmission lines (0.1 µT) and two three-phase primary distribution lines (0.11 µT). Lower exposures were associated with a single-phase primary line (0.07 µT) and a two-phase primary line (0.05 µT).

  • Many sudden field changes were recorded where the field value was more than 50% different from the average of two consecutive readings. The percentage of people experiencing more than 10 sudden field changes of over 1.0 µT, over 0.5 µT, and over 0.25 µT are over 30%, over 50%, and over 90%, respectively. Those data undoubtedly reflect intermittent exposures from local sources (such as appliances) or other types of power switching in the environment of the exposed person.

Three aspects of the study design reduce the ability to generalize from the results that were obtained:

  • A low participation rate (28.4%) based on consent forms returned relative to the number of initial telephone contacts.

  • The percentage of those age 17 yr or under studied in this project (8.2%) is only onehalf the percentage of those age 17 yr or under in the US population (16.6%).

  • All measurements were made in the coldest months of the year (November to March).

Project 7: "Hazard Surveillance for Workplace Magnetic Fields: I. Walkaround Sampling Method for Measuring Ambient Field Magnitude and II. Field Characteristics from Waveform Measurements" (National Institute for Occupational Safety and Health).

This study (NIOSH 1998) provided a description of procedures for characterizing occupational MF exposures with a portable data logger (the EMDEX-II) and a waveform-capture system that enables evaluation of the field magnitude, frequency spectrum,

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

polarization, spatial orientation, and total harmonic content. The walkaround surveys with the portable exposure meter were conducted in 62 facilities, ranging from a small print shop to a large oil refinery. The results of the surveys demonstrated two aspects of workplace exposures: the electric-power consumption in a given facility cannot be used reliably as an indicator of worker exposures to MFs, and the Standard Industrial Classification is not a reliable tool for predicting worker exposures.

The waveform-capture system was used in six diverse industries: aluminum extrusion, aluminum-framed filters preparation, plastic-polymer production, liquid air separation, cement production, and pharmaceutical manufacturing. A problem that was encountered during these measurements was an effect on the waveform resulting from motion of the field probe. An algorithm was developed to correct for this motion, but the algorithm was not very reliable. On the basis of 59 waveform measurements, the recorded fields showed significant second, third, and fifth harmonics, with a total harmonic distortion of about 15%.

Project 8: "Evaluation of Field-Reduction Technologies" (IIT Research Institute and Commonwealth Associates)

This study (IIT 1997) involved an in-depth evaluation of exposure-mitigation procedures for nearly all common sources of human exposure to power-frequency MFs, including powerlines and substations, electric-power service connections in homes and businesses ("customer-side" power distribution), appliances and machine tools, and electric transportation systems. Four types of reduction were considered: self-cancellation methods, such as split currents moving in opposite directions or magnetic dipoles with oppositely directed vector orientations; active cancellation using bucking coils; field cancellation by inducing eddy currents in nearby metal structures; and shielding with ferromagnetic materials. For the various field-reduction methods, cost estimates were provided on the basis of required materials and labor, project costs (including land purchase, permits and licenses, and engineering surveys), and life-cycle costs (management and operations, interest on leases, property taxes, and insurance). The conclusions of this study were as follows:

  • For powerlines, unbalanced current is the main source of MFs. This is the case for the MFs from distribution lines and for household wiring. A variety of field-reduction methods can be used, including balancing the current load, using splitphase configurations, compacting conductor bundles, placing cables underground, and decreasing the current while increasing the voltage to maintain the same load.

  • Customer-side power distribution sources that were evaluated included electric service panels, transformers, switchgear, and wiring. Field-reduction methods include correcting the return-current imbalance and avoiding ground-current loops, using metal conduits, installing shielding for panels and switchgear, the use of shielded and twisted-pair wiring, and using three-conductor wires. The overall cost of upgrades in wiring can be 50% to 100% greater than the cost of standard wiring.

  • In appliances and machinery, the main sources of MFs are small motors, resistive heating elements, meters, transformers, and wiring. A variety of methods are generally available to reduce a stray field at little cost, including split-return currents, shunt connections, and toroidal coil winding in transformers. However, some

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

machinery, such as welding and melting machines and electric furnaces, pose difficult problems in achieving field reduction.

  • For electric transportation systems, the main sources of stray MFs include motors and unbalanced currents. These sources can lead to very high MF levels in passenger cars (1.0–10.0 µT at 60 Hz). However, significant field reduction can be achieved by using dual overhead-trolley connections, return current wires that are close to the supply wires, and DC currents. Shielding with ferromagnetic materials is not practical, because of the added weight.

Project 9: "Characterization of Exposures to Extremely Low Frequency MFs in the Office Environment" (University of Washington Master's Thesis in Environmental Health prepared by P. Hogue).

The purpose of this study (Hogue 1995) was to characterize exposures to power-frequency MFs in an office environment on the basis of data obtained from 70 workers in a single company at 12 sites. Comparisons were made between spot measurements of fields in the work location and exposure data obtained with a personal exposure meter, the EMDEX Lite. Exposure measurements were made for 24 h, thereby obtaining additional useful information on nonwork exposures of each subject. The primary findings in this study were as follows:

  • The arithmetic mean value of the MF measured with a personal exposure meter for the office environment was 0.17 µT; for nonwork exposures (mostly at home), it was 0.14 µT. From the cumulative data, the average office exposure during a typical workday contributed about 35% of the total average 24-h exposure (8-h average).

  • For office workers, the within-day variability was greater than the between-day variability. The greatest variability in exposure levels was observed between subjects.

  • The exposure data were found to be quite stable when measurements were collected at time intervals separated by up to 62 d.

  • No significant variation in the office exposure levels was observed as a function of time of day.

  • Spot measurements of the MF levels were found to correlate well with measurements made with the EMDEX Lite personal exposure meter; spot measurements were able to account for about 65% of personal work-exposure variability.

Project 10: "Assessment of Human Exposure to Magnetic Fields Produced by Domestic Appliances" (EM Factors)

The primary purpose of this study (EM Factors 1996) was to assess the reliability of estimating MF exposure with questionnaire data on electrical-appliance use in the home. Predicted exposures based on questionnaire data and measurements of the MFs produced by various appliances were compared with personal-exposure data acquired with an EMDEX-II meter worn at the waist. The study, conducted in Avon, England, involved 50 women; 805 measurements were made on fields from 50 types of household electrical appliances. The following is a summary of the major findings in this study:

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×
  • No correlation was found between measurements of fields produced by appliances and actual exposures measured with an EMDEX meter.

  • The personal-exposure data correlated reasonably well with an exposure model that included measured average fields in the kitchen and bedroom, independently of appliance contributions to the variability in the measured fields. Similarly, peak exposures were unrelated to the use of any appliance.

  • The results of this study indicate that questionnaire data on the amount of time that various appliances are used cannot be relied on as a basis for estimating exposure to the power-frequency MFs emanating from household appliances.

  • A model was developed that accounts for the effects of some commonly used appliances on the 90th percentile of peak exposures. Three appliances that were used more than 15 min/d at operating distances of less than 100 cm and that fit this model were a microwave oven, a conventional oven, and an electric cooker. Electric blankets were not included because only four of the 50 subjects used them. The model also was found to be applicable to characterizing exposures to fluctuating MFs at the 90th percentile of peak values.

  • The median exposure of the subjects in this study was one-fourth to one-third of the exposures found in a previous large study of a comparable nature in the United States. This difference is probably related to the use of 240-V line voltages in the UK rather than the 120-V used in the United States, with correspondingly lower currents that give rise to lower MFs. Also, the report notes that electricity in the UK is quite expensive, and therefore is used more sparingly than in the United States.

Project 11 "Risk Dimensions of the EMF Problem" (Center for Risk Management, Resources for the Future)

The report of this project (Florig 1995) was delivered to the committee in connection with the engineering program, but it is actually a risk-analysis report rather than an engineering report. The objective of the project was to use epidemiologic information available up to 1995 to put the potential cancer risk posed by MF exposure into the broader context of risks posed by other environmental agents. The report is the opinion of one person, who also attempted to analyze the impact of information on EMF-exposure health risks on public policy and regulatory restrictions on exposure. The author apparently believes that power-frequency magnetic fields pose a childhood health hazard and that MF studies might be biased toward null results. He criticizes expert panels and government agencies in their handling of MF issues. This committee notes that the literature base on which this report was developed is now out of date, and therefore questions the utility of the conclusions of the author on cancer risk related to MF exposure.

Summary

EMF-RAPID committed about $2.7 million to engineering studies an amount that is 6.6% of the total budget of $41 million. The overall value of what has been accomplished in the 11 engineering projects funded as part of the EMF-RAPID program is questionable. The projects were commissioned without any convincing evidence of specific linkages between low-level MF exposure and human health effects. As a result, the engineering projects were designed to establish field-measurement and management

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

technologies for ill-defined possible future discoveries of biologic effects of power-frequency fields. There is a considerable degree of overlap and repetition among several of the individual projects. Many of the projects have "the cart before the horse", in the sense that they anticipate all possible field parameters of potential relevance, without good reason to focus on any specific one. A considerable amount of money has been spent to fund work that will probably never be used. Furthermore, the work was done concurrently with other EMF-RAPID studies, so the results of the engineering projects could not be used in the biology projects.

Three projects (projects 1, 2, and 4) had as goals the establishment of MF measurement methods and protocols. In the absence of real knowledge of what field properties might be of concern, a large number of possible field metrics were evaluated in these studies. A large amount of detail was provided about how to characterize a wide variety of field properties. However, in the absence of any established health effects associated with EMF exposure, it is not evident which, if any, of the measured field parameters are relevant. A fourth project (project 5) was concerned with the establishment of a database to serve as a "repository" for data generated in engineering studies of MF environments. Again, a significant effort has gone into the creation of the structure of this database without knowledge of the specific issue that the data will address. In addition, the large sets of individual exposure data obtained under funding from the EMF-RAPID program (projects 3, 6, 7, 9, and 10) have not been entered into the database at the time of this review. The measurement protocol and database projects probably will never be needed. At the least, this work would have been much more efficiently carried out after the establishment of a specific biologic effect.

The five individual-exposure data projects (projects 3, 6, 7, 9, and 10) involved determinations of levels of MF exposure in a variety of specific environments (household, work, office and so on). A large amount of detailed data was collected, but it is not likely that the bulk of it will ever be used. The overall conclusion from this work is that field exposures do not vary a great deal from one type of environment to another. On the basis of personal-exposure measurements, the time-weighted-average (TWA) MF levels to which most members of the US population are exposed are in the range of 0.1–0.2 µT. In that range, exposures at work and in some transportation vehicles are generally greater than those experienced in the home. TWA exposures above 0.2 µT are relatively infrequent among the general population, although occupations that involve working in close proximity to industrial machinery and business machines can lead to TWA exposures in excess of 0.4 µT.

Of the 11 projects, only one (project 8), which addressed field-reduction methods for a variety of sources and made comparisons of costs for various levels of reduction, provides information on what can be done to mitigate MF exposure if it is ever found necessary. This work could also be of some value with regard to field-reduction applications unrelated to health effects. Some of the methods described for reducing fields from powerlines are being used in new installations. It was also noted by the committee that EPRI has funded work on methods for reducing fields from powerlines and other sources.

It is not difficult to envision MF measurement studies that could be done to provide large volumes of data that might be useful if some causal effect is determined to exist. But to provide substantial funding for such studies without specific guidance from

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

documented and replicable biologic effects makes little sense. In order to do good science and good engineering, it is essential to distinguish between repeatable results that correspond to testable hypotheses and empirical observations that are not predicted and not reproducible. Large amounts of data do nothing to strengthen claims of cause and effect that are fundamentally weak.

Without a much more compelling case than has been made to date, future engineering studies of the kind that were funded in the EMF-RAPID program are not recommended.

NIEHS Biology Projects

The Energy Policy Act of 1992 directed that research be carried out to "determine whether or not exposure to EMFs produced by the generation, transmission, or use of electrical energy affects human health". The biologic-research portion of the EMF-RAPID program was to address mechanisms by which MFs interact with biologic systems and to conduct epidemiologic research on the possible health effects of MFs. A decision was made early in the EMF-RAPID program to de-emphasize the epidemiologic effort, possibly because of funding restrictions and the existence of a number of epidemiologic studies already funded by other sources. Most of the EMF-RAPID-funded biology projects were intended either to investigate ELF-MF effects on biologic processes related to cancer or to fundamental cellular processes, such as signal transduction and gene expression. Most important, efforts were made to have independent investigators repeat previous experiments that reported MF effects. The EMF-RAPID program funded projects that examined the interactions of MF exposure with initiation and promotion of cancers by using established animal carcinogenicity models. These experiments were intended to serve as controlled laboratory tests of the carcinogenicity implied by the epidemiologic studies that reported associations between measurements assumed to indicate increased MF exposure and increased occurrence of cancer. The EMF-RAPID program also funded a number of studies that were designed to provide specific information on, or at least reduce the uncertainties about, the interaction of MFs with biologic systems and ultimately reduce uncertainties about adverse effects of MFs on human health. Because the possible mechanisms of MF interaction that could have carcinogenic effects are unknown, the relevant exposure metric cannot be determined with confidence.

Scientific data of relevance to the question of possible health effects can be obtained from laboratory studies involving animals and studies involving cells in culture. Two activities in the program were designed to ensure that in vivo and in vitro research funded under this program would have the benefit of accurately determined exposures. Grantees were provided with a site-visit team that inspected and calibrated exposure facilities. Another activity established four regional exposure facilities that would be available for experimentation under the EMF-RAPID program: such facilities were established at the Food and Drug Administration (Washington, DC), at the National Institute for Occupational Safety and Health (Cincinnati, Ohio), at the Pacific Northwest National Laboratory (Richland, Washington), and at Oak Ridge National Laboratory (Knoxville, Tennessee). The goal was to have standard facilities available for replication of important experiments. These facilities were primarily used by researchers working at

Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
×

the four sites. It can be assumed that these two measures assisted in ensuring a more uniform and higher quality of MF research conducted under the EMF-RAPID program.

Most of the biologic research under EMF-RAPID was funded through NIH research grants, a mechanism that seeks investigator-initiated research-grant applications. In this case, such applications were produced in response to Requests for Applications (RFAs) describing the subjects of interest and the types of applications that the agency (NIEHS) desired to review and fund. In the NIEHS EMF-RAPID research program, 49 applicants were funded from proposals received in response to RFAs—approximately a 25% success rate. In addition, 12 projects were funded in-house at NIEHS with EMF-RAPID funds and were not competitive responses to RFAs. NIH grantees briefly report their progress in non-competing renewal applications and peer-reviewed publications.

The biology projects included screening studies, tests of formal hypotheses, and replications of previous claims of effect. The committee would have preferred to see more studies directed at replication of published claims of effects and formal hypothesis testing and fewer studies directed at screening for possible effects. Without development and testing of specific, well-defined hypotheses, the ability to draw firm conclusions regarding the biological interactions and potential health effects of power-frequency fields is very limited.

The importance of the NIEHS biologic research effort lies in the general observation that the results to date of this special, focused, 4-yr research effort tend to diminish, rather than increase, scientifically-based concern that use of electric power entails serious adverse health effects. Many of the investigations showed that the in vitro effects of MF exposure reported in the literature could not be replicated, and no link has been established between laboratory MF effects on a particular cellular process and the occurrence of adverse human health effects. Efforts to examine promotion by MF in animal cancer models did not detect increases in cancer incidence or tumor growth rates.

In an effort to evaluate MF health effects, EMF-RAPID funded 61 biologic studies. At the time of this committee's assessment, few of the studies had been published in the peer-reviewed literature. The committee was furnished with detailed and complete reports of the DOE engineering studies, but the brief project summaries of the bioeffects program supplied to the committee contained little quantitative information. Without extensive data on the magnitude of the effects and their reproducibility, it was difficult to evaluate the biologic studies adequately or to assess the program's impact on the existing body of knowledge related to the bioeffects of electric and magnetic fields3.

The results of all 61 biologic studies funded by EMF-RAPID are summarized in the tables beginning on page 39. For the purposes of the committee's review, the biologic studies were grouped into five categories:

  1. No MF results reported in project summary. These are projects that at the time of reporting had not produced either positive or negative findings.

  2. No MF or EF effects reported. These are studies in which the investigators sought but were unable to find effects of EF or MF exposure.

3  

Bioeffects research supported by EMF-RAPID has been concerned almost exclusively with the effects of power-frequency MFs. Only two studies involved direct exposure to electric fields. Only two MF studies used frequencies other than 60 Hz.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
    1. Effects reported but data insufficient to calculate magnitude of effect.

    2. EF and MF effects reported and data sufficient to calculate magnitude of effect.

    3. Attempts to replicate earlier positive reports. These studies attempted to reproduce earlier reports of MF effects.

    In about one-quarter of the preliminary reports, positive findings were indicated. In these cases, the responsible investigators were invited to supply supporting data. On the basis of their replies, it was possible to estimate the magnitude of the effects that are shown in the tabular summaries. Some of the investigators did not reply, and in some cases the information supplied could not be interpreted quantitatively. The 36 project summaries classified into the first three categories are of limited value at this time for determination of the possible health effects of electric and magnetic fields. If the investigators reported effects but did not provide supporting data, the committee could not evaluate the magnitude of the reported effect.

    Even Category 4 (effects reported and information sufficient to calculate magnitude of effect), when placed in the context of the long history of investigations in this field, has limited value. Of the hundreds of claims of biologic effects of ELF MFs, only a few have been independently confirmed; in these cases, there has usually been a rudimentary understanding of the mechanisms of action of the fields. In contrast, a number of claimed effects have failed the test of independent replication. The reports of MF health effects available to the committee do not always give the rationale for the work, but most of the projects were probably extensions of earlier investigations. In light of the history of this field of investigation, these results, without independent confirmation, have little value in answering the basic question of whether there are biologic effects of low-level power-frequency MFs.

    Category 5 (replications of earlier positive reports) has been by far the most valuable part of the EMF-RAPID program. Evaluation of the question of possible health effects of power-frequency MFs is handicapped by the absence of robust effects that can be reproduced consistently from one independent laboratory to another. No serious progress on understanding of MF health effects, if they exist, can be made until such reproduction occurs. Conventional funding mechanisms discriminate against applications that propose to test whether some other investigator's findings are valid but requests for proposals from the EMF-RAPID program deliberately encouraged replications.

    Although many unconfirmed claims of biologic effects have been made during the course of more than 2 decades of effort, very little of the work to date has been mechanism-based research. If any of these effects turn out to be valid, they could provide the much-needed starting point for such systematic research. That is why replication studies are important at this point in the development of MF bioeffects research. If carefully performed, these experiments have value, even if their results are negative. All of the replication studies performed under EMF-RAPID had either negative or equivocal results.4

    4  

    The Committee is aware of an unpublished series of replications that has taken place under other sponsorship. Three replication studies support the observation by Liburdy and co-workers that low-intensity 60 Hz MFs eliminate the slight inhibitory effects of melatonin and tamoxifen on the growth of tumor cells in vitro. This might constitute the kind of confirmation that has been needed, but it will be necessary to evaluate the replications after their publication in peer-reviewed journals.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Biology Tables

    The results of the 61 biologic studies commissioned by EMF-RAPID have been summarized in a series of tables (2.12.5). For the purposes of the Committee's review, the biologic studies fall into five categories:

    1. No MF results reported in project summary (18 projects).

    2. No MF or EF effects reported (10 projects).

    3. Effects reported but data insufficient to calculate magnitude of effect (8 projects).

    4. EF or MF effects reported and data sufficient to calculate magnitude of effect (7 projects).

    5. Attempts to replicate earlier positive reports. This category includes studies that attempted to reproduce earlier reports of MF effects (18 projects).

    Categories 4 and 5 have been subdivided into in vivo and in vitro studies.

    Blank cells in the tables indicate that information was not available. The magnitude of a reported effect (tables 2.4a & b) is a number obtained by dividing the difference between exposed and sham samples by the standard deviation of the effect. Thus, a magnitude less than unity indicates that the effect is less than the standard deviation. The magnitude of a reported effect provides some perspective on whether the claimed effect is real and how important it could be from a biologic point of view. Effects that are small relative to experimental variability are difficult to establish experimentally and often are regarded as unimportant biologically. Projects in tables 2.4a and 2.4b reported at least one effect with data sufficient to estimate the magnitude of the effect. Unless otherwise indicated the frequency of the exposure is 60 Hz. When appropriate, additional information is provided as text describing the tabled material.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.1 lists project summaries that reported no MF results at the time of the EPACT Committee review (July - October 1998). No evaluation of the projects in this category, other than the descriptive material presented in the table, is possible at this time.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.1—No MF Results Reported in Project Summary

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Astumian

    Univ. of Chicago

    Nonlinear mechanisms of field effects on cells-entirely theoretical

    None

    Theoretical study, no MF results

    1997

    Author proposes to ''develop theories of biophysical mechanisms that deal with biologically relevant MF exposure conditions"

    Barrett

    NIEHS

    Effects of melatonin on cell proliferation

    No MF exposure

    No MF results. Melatonin does not inhibit estrodiol-induced MCF-7 and BG-1 tumor cell proliferation

    1994

    Some previous reports indicated that melatonin can reduce cell proliferation

    Bilski

    NIEHS

    Study of reactions of biologic, transient neutral free radicals and radical ions that might be affected by MF exposure

    Exposure facilities not available at time of report

    No MF results reported

    1993

    Recent speculation regarding prolongation of free-radical life span by MF exposure as a mechanism of MF effects

    Binninge

    Florida Atlantic Univ.

    Effects of MFs on gene expression in yeast

    20 µT, 60 Hz AC; exposure duration not reported

    No results reported

    1994

    Historical interest in MF-induced gene expression based on results of Goodman and others

    Blumenthal

    NIEHS

    Model of melatonin production, distribution and elimination

    None

    Development of physiologically based pharmacokinetic model for melatonin; no MF results

    1994

    Pharmacokinetics of melatonin might be relevant to potential MF effects

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Chignell

    NIEHS

    Rate constants of melatonin reactions with free radicals and singlet oxygen

    None

    No MF exposure involved, so no MF results; indoles reacted rapidly with free radicals

    1993

    Previous indications of MF effects on melatonin concentrations and melatonin's action as a free-radical scavenger

    Craviso

    Univ. of Nevada

    MF effects on calcium in excitable cells

    ~1 mT

    No MF results reported, "data being evaluated"

    1997

    General interest in intracellular calcium as function of several MF measures

    Griffin

    Oak Ridge National Laboratory

    MF effects on cell-cell communication in rat liver cell line

    8–50 µT, 45 Hz; 37 µTDC parallel; <0.2 µT perpendicular

    No MF results reported; "delay in start of funding"

    1997

    Replication study of observations by Benane and by Blackman of MF effects on cell-cell communication (Blackman and others 1993; Benane and others 1996)

    Hahn

    Virginia Medical Center

    Brain tumors in mice exposed to 60-Hz MFs

    1.4 mT, 18 h/d from wk 4 until death or age 29 mo

    No results reported; study not completed at time of committee review

    1997

    Some epidemiologic studies link MF exposure to increased brain-cancer incidence in humans

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Harry

    NIEHS

    Alterations in GAP-43 mRNA in rats after exposure to MFs

    2, 200, and 1000 µT for 18.5 h/d continuously and 1,000 µT for 18.5 h/d intermittently (lh on and 1 h off); throughout both pregnancy and postnatal period

    No results reported; study not completed at time of committee review

    1996

    Authors state that project addresses possible effects of MF during neonatal period; a few studies suggest MF effects on neural development

    Litovitz

    Catholic Univ.

    Mechanisms of MF-induced bioeffects

    Exposure not described

    No results reported; study not completed at time of committee review

    1995

    Investigation and characterization of mechanisms by which cells detect and respond to weak MF

    Mandeville

    Univ. of Quebec

    MF effects on brain-tumor promotion in rats [ENU initiation]

    < 0.02, 2, 20, 200, and 2,000 µT for 20 h/d applied from 18 d prenatal to 60 wk postnatal

    No results reported, study not completed at time of committee review

    1994

    Certain epidemiologic research suggests MFs might act as promoter in carcinogenesis, including development of brain cancer

    McCormick

    IIT Research Institute

    Potential health effects of MFs on pineal function in rats and mice

    0.2 mT, 60 Hz with transients added, intermittent fields, and 60-Hz fields with added harmonics; 4 wk of exposure

    No results reported, study not completed at time of committee review

    1997

    Considerable past research on MFs and melatonin in rats, including speculation on role of transients

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Murphy

    NIEHS

    Ion changes in apoptosis as possible mechanism of MF effects

    No MF exposure

    No MF results

    1993

    Some studies have suggested changes in Ca2+ transport with MF exposure; author hypothesizes that altered Ca2+ homeostasis enhances neoplastic progression

    Murphy

    NIEHS

    Signal-transduction pathways responsible for oncostatic properties of melatonin; use of BG1 cells

    No MF exposure

    No MF results

    1993

    Elucidation of signaling pathways involved in oncostatic action of melatonin

    Putney

    NIEHS

    Effects of MFs on calcium signaling in S49 and Jurkat cells

    "No MF exposure" (Walleczek 1992 used 6 mT)

    No MF results

    1994

    Putney proposed to replicate a report on calcium signaling in immune-system cells (Walleczek 1992)

    Sheppard

    Loma Linda Univ.

    Analysis of epidemiologic studies

    Epidemiologic studies; no exposure involved

    No results reported

    1997

    Combined analysis of 13 epidemiologic studies of childhood leukemia to estimate fraction of cases of childhood leukemia attributable to MFs

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded

    (FY)

    Rationale

    Travlos

    NIEHS

    Effects of nocturnal melatonin on progression of breast cancer induced by methyl nitrosourea (MNU) in F344/N rats

    None

    Although light-burst treatment affected melatonin, no clear relationship between melatonin and cancer induction by MNU was found; not an MF study, therefore no MF results

    1997

    Earlier suggestions that melatonin affected development of breast cancer

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.2 lists project summaries that report no effect of EF or MF exposure

    Two of the studies (Hei and Glickman) investigated mutational effects. Hei reported on the comutagenicity of MFs and gamma radiation; the results indicated that MFs did not have the capacity to enhance the cytotoxicity or mutagenicity of gamma radiation. Glickman investigated both the potential comutagenicity of MFs and NiCl2 at the lacI locus in the transgenic R2LIZ rat fibroblast cell line and the potential mutagenic effect of MFs at the lacI locus in the Big BlueT transgenic mouse. Glickman reported no MF effect on R2LIZ cell survival. No mutation results had been reported at the time of this review.

    Hong investigated the role of tyrosine phosphorylation in response to 60-Hz MF exposure. The data showed no change in the activity of the epidermal growth factor (EGF) receptor after MF exposure of A431 cells. It is relevant to this study, however, that A431 cells have an extremely high concentration of the EGF receptor, which makes them a useful source of this protein tyrosine kinase receptor but might not make them a useful test system for studying the influence of a weak upstream signal. It should be noted that the negative results regarding the EGF receptor, despite the concerns about the validity of A431 cells as a model system, are in sharp contrast with the alleged MF effects on activity of the Lyn kinase in B-cell lymphomas (see Uckun, table 2.3).

    Reiter tested the possibility that MF exposure increases free-radical longevity, resulting in increased damage to DNA. Rats were treated with safrole, a carcinogen that increases free-radical production in vivo, and liver concentrations of 8-hydroxyguanosine and average number of micronuclei per cell were measured 8 h after exposure; these indirect measures of free-radical damage were increased by the safrole treatment. Other rats were given safrole and then exposed to a 0.1-mT MF for 8 h. MF exposure had no detectable effects on concentrations of 8-hydroxyguanosine and number of micronuclei greater than those produced by safrole. These observations do not substantiate any MF-induced increase in radical half-life.

    In the study by Marino on immune-system changes in mice no overall consistent effect of MFs was apparent to the committee.

    Kripke noted that it was "too early to form a basis for positive or negative conclusions" in a study on melatonin concentrations in elderly human volunteers.

    No effects were reported for EFs on yeast H+ATPase (Astumian), or for MFs on p53 expression in normal human lymphoblastoid or ataxia telangiectasia cells (Loberg), maternal toxicity in study using rats (Ryan), and on a variety of end points in brain-cell cultures obtained from embryonic mice (McMillian).

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.2—No EF or MF Effects Reported

    PI

    Topic

    Exposure

    Result

    Funded

    (FY)

    Rationale

    Astumian

    Univ. of Chicago

    Sensitivity of yeast H+ATPase to EFs

    1 mV/m to 100 V/m, 1–100,000 Hz

    No effects of applied EFs on yeast H+ATPase; reference is made to a doubling of NaK-ATPase response, in which theory suggests a much larger effect

    1994

    PI hypothesizes that H+ATPase will show EF dependence similar to that seen with Nak-ATPase, in which both frequency and amplitude optimums have been observed

    Glickman

    Univ. of Victoria

    MFs, chemical toxicity, and comutagenesis in vitro

    MF mutagenesis in vivo

    2 mT for 120 h

    3 mT for 8 h/d for 12 wk

    Nickel toxicity not enhanced by MF exposure

    No mutation data on MF exposure at time of this report

    1997

    Mutagenesis thought to be prominent in mechanisms of carcinogenesis

    Hei

    Columbia Univ.

    Comutagenicity at SI and hgprt loci in AL cell line after MF and gamma-radiation exposure

    1.5 or 3 Gy followed by 50 and 60 Hz, 100 µT for 1–7 d

    MFs did not enhance cytotoxicity or mutagenicity of gamma irradiation

    1997

    Mutagenesis thought to be prominent in the mechanisms of carcinogenesis

    Hong

    NIEHS

    MF effects on tyrosine phosphorylation in A431 cells in vitro

    0.1 mT for 0.5–8.0 h

    No MF effects revealed in experiments conducted in two laboratories (Environmental Protection Agency and University of North Carolina)

    1994

    Tyrosine phosphorylation as mechanism of signal transduction and carcinogenesis

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Kripke

    Univ. of California, San Diego

    MF effects on melatonin in elderly volunteers

    Personal exposures up to 3 µT, with median at 0.05 µT

    No effect of MF exposure on melatonin concentrations

    1997

    Interest in MF effects on melatonin concentrations, which are reduced in elderly

    Loberg

    IIT Research Institute

    MF effects on gene regulation in ataxia telangiectasia and normal lymphoblastoid cell lines

    10 µT and 1 mT for 1, 3, 6, or 24 h

    No MF effect on p53 expression in normal or AT cells

    1997

    Testing hypothesis that MFs can modulate cellular responses to agents that damage DNA via effects on cell regulatory pathways

    Marino

    Louisiana State Univ. Medical Center

    MF-induced changes in immune system of mice

    0.5 mT for 1–49 d in one experiment and 175 d in another

    In three replicate experiments, T cells, B cells, and corticosterone were assayed; corticosterone concentrations were sometimes increased and sometimes decreased in MF groups relative to controls; no overall consistent effect apparent

    1995

    Testing hypothesis that exposure to environmental power-frequency magnetic fields can impair immunosurveillance

    McMillian

    NIEHS

    Evaluation of MF effects on neuronal development

    0.002, 0.2, and 1 mT intermittently, or 1 mT continuously, for 18.5 h/d

    "Correlations with EMF dose-exposure were generally lacking"

    1993

    Epidemiologic suggestion of increase in brain tumors associated with MF exposure

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Reiter

    Univ. of Texas Health Science Center

    MF effects on DNA damage in rats as determined by 8-hydroxyguanosine and micronuclei formation

    0.1 mT for 8 h

    No statistically significant increase in 8-hydroxyguanosine or micronuclei after MF exposure

    1997

    To test hypothesis that MFs increase half-life of free radicals, thereby increasing probability of DNA damage

    Ryan

    IIT Research Institute

    Developmental toxicology of MF exposure in rats

    Dams were exposed to 0.2 mT during gestational days 6–19 for 18.5 h/d or to third harmonic (180 Hz) or playback of 20 recorded transient events. Harmonics and transients were superimposed on 60 Hz

    Maternal toxicity not observed; no results available for fetuses

    1997

    Hypothesis that transients of MF exposure and harmonics might adversely affect development of fetus

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.3 lists project summaries that report MF effects but in which the information provided is insufficient to calculate the magnitude of the effect. Project evaluations, other than the brief descriptions presented in table 2.3, are not warranted. Some comments on methodology are noted below.

    The Luben project to study membrane receptor function was based on results from a previous collaboration with Uckun (Uckun and others 1995), in which it was reported that 0.1-mT (60-Hz) MFs activate the Lyn kinase in B cells. The data on Lyn kinase and tyrosine phosphorylation in the Uckun paper (used as a rationale for the present EMF-RAPID project) appear to be adequate and reasonably well controlled. The data on phosphokinase C (PKC), however, are limited in that the studies on PKC activity were restricted to assays of membrane fractions for phosphorylation of a peptide substrate. The use of protein kinase inhibitors allegedly specific for PKC is the only evidence that the activity measured was due to PKC. Rinehart reports that MF exposure enhances the growth of some human epithelial cultures, although supporting data are minimal. The project also investigated gene expression with endometrial stromal fibroblasts. Studies on gene expression of the type described have major limitations in that they focus on a narrow repertoire of messenger RNAs. C-myc and gro do not adequately cover the spectrum of possible changes in gene expression. Studies by Woloschak on MF that used a differential display method did detect changes in gene expression; genes were both induced and repressed after 1.0-mT exposures. However, the changes were small, and the significance of this effect can be assessed only after the results are published.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.3—Effects Reported, but Information Insufficient to Calculate Magnitude of Effect

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Costa Univ. of Washington

    Investigation of MF effects on proliferation of mitogen-stimulated human astrocytoma cells

    0.06–0.12 mT; exposure duration not provided

    Increased cell proliferation in human astrocytoma cells

    1997

    Suggestion in some epidemiologic studies of increase in brain tumors associated with MF exposure

    Grissom

    Univ. of Utah

    Effects of DC fields on enzyme reactions

    1.0 mT to 1.0 T; exposure duration not provided

    Small effects on enzyme rate constants at very high DC MF levels.

    1997

    Some historical interest in possibility that MF can moderate enzyme reaction rates

    Luben

    Univ. of California

    MF effects on membrane receptor function

    0.1 mT; exposure duration not provided

    Description of first-yr results appears generally consistent with earlier, related experiments

    1994

    Earlier reports of PI and others that MFs affect concentration of PKC and cellular pathways related to it

    Pennypacker

    NIEHS

    MF effects on proto-oncogene-DNA binding during brain development

    2, 200, and 1,000 µT, continuous exposure, or 1 h on and 1 h off, for 18.5 h/d during gestation and 3 d postnatal

    AP-1 binding reportedly lowered by exposure, but no data provided; AP-1 binding assumed to be indicator of early brain development

    1994

    Hypothesis that MF affects early brain development and results in neurobehavioral dysfunction

    Rinehart

    Univ. of North Carolina at Chapel Hill

    Evaluation of transforming potential of MF

    0.01–0.2 mT, short-term exposure for 1 h, chronic exposure for 30 min, 3 times/wk

    No effects of 1-h exposure seen on c-myc and gro gene expression or in cell cycle; intermittent long-term exposures accelerated aging; anchorage-independent proliferation of some cancer cell lines increased

    1994

    Previous work by other investigators that suggested MF effect on c-myc or gro messenger expression

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Rationale

    Sisken

    Univ. of Kentucky

    Effects of MFs on calcium entry in cultured cells

    0.3 and 50 mT; exposure duration not provided

    Data from oral presentation show calcium increases of around 10%, but data insufficient to determine statistical significance

    1997

    Previous studies suggesting that changes in Ca2+ transport with MF exposure affect cellular proliferation

    Uckun

    Univ. of Minnesota

    Stimulation of protein tyrosine kinases (PTK) in human B-cell lymphocytes by MFs

    1–1,000 µT; exposure duration not provided

    Stimulation of PTK reported, but no data provided

    1995

    MF exposure of lymphocytes might stimulate tyrosine kinases, which are implicated in progression of leukemias and lymphomas (Luben, Byus, and others have reported MF effects on tyrosine kinases)

    Woloschak

    Argonne National Laboratory

    Changes in gene expression accompanying exposure to MFs

    0.1 and 1 mT for 24 h

    Preliminary data show ''modest induction of a few genes" at exposures of 1 mT for 24–72 h

    1994

    Historical interest in MF-induced gene expression based on results of Goodman and others

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.4a lists project summaries that report in vitro EF or MF effects and contain sufficient information to estimate magnitude of effect.

    The study by Goodman on the copromotion of cancer by MF was directed largely at gene expression of c-myc and p53 in cells. Although Goodman reports no publications from the grants supported by the EMF-RAPID program, the group has five publications related to MF effects (Goodman and others 1989; Goodman and Shirley-Henderson 1990; Goodman and others 1992; Lin and others 1994; Goodman and Blank 1998). These mainly involve a study of effects of MF exposure on gene expression—for example, of the myc gene—or in the induction of heat-shock proteins. It is an enigma why the results in the Goodman publications on MF and heat-shock proteins disagree with other studies supported by the current program, which find no changes in gene expression or heat shock protein expression, for example, Saffer and Thurston 1995 and Owen 1998 (see table 2.5a).

    Aaron presents preliminary data on increased glycosaminoglycan content per milligram of tissue on days 7 and 9 of MF exposure but not on days 3, 5, and 11. A significant increase is observed at 0.07 and 0.1mT but not at other doses. Aaron concludes that the 60-Hz field accelerates chondrogenic differentiation and synthesis of cartilage. He suggests further that the data indicate that Tumor Growth Factor-ß (TGFß) responses are a possible mechanism of the observed increases in differentiation. In 1998, the investigator has one paper in press and two others in preparation that involve these studies on differentiation and on TGFß synthesis. The author hypothesizes that MF exposure alters endochondrial ossification, a process central to skeletal embryogenesis.

    Blank and colleagues suggest that stress responses in cells might be measured by determining changes in cytochrome oxidase function and the rate of electron transport. They conclude that 60-Hz MFs increase the oxidation rate constant of cytochrome oxidase by 20–30% at field strengths below 3 µT and by a factor of about 2 between 6 and 10 µT. Those data on MF effects on cytochrome oxidase are similar to effects on Na+/K+-ATPase reported earlier by Blank. One paper on these experiments has been submitted for publication. The committee questions the rationale that cytochrome oxidase is an indicator of stress in cells but notes that the results appear to be significant if the conclusions are limited to the studies on enzyme reaction rates.

    Liburdy presents an extensive report on preliminary studies on the influence of MFs on signaling processes; the investigator describes a number of measures for the study of mitogen-activated calcium transport in rat lymphocytes. The preliminary conclusions suggest that MFs increase intracellular calcium and enhance signal transduction, but not to the extent that cell viability is affected. The investigator also suggests that MFs act synergistically with an activating agent, such as anti-CD3 antibody, to enhance signal transduction in lymphocytes. The objective was to test the hypothesis that time-varying (AC) MFs interact with biologic systems in a manner that depends on the presence of static DC MFs. The specific aims were to determine whether particular AC-DC combinations increase or decrease calcium signaling in mitogen-activated thymocytes and, if so, to determine whether the changes increase or decrease cell viability or proliferation. The PI indicates that MF exposure can increase intracellular calcium in Jurkat cells activated with antibody to the CD3 cell surface receptor. Scatchard analyses indicated that binding was increased by 25–30% after brief (10–15

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    min) MF exposures. The PI regards this as biologically relevant. A dose-response study at 100, 1,000, or 10,000 µT indicated a monotonically increasing effect.

    McLeod and co-workers reported small effects on cell proliferation, alkaline phosphatase concentrations, and cell shape and orientation when bone cells were exposed in vitro to ELF MFs of around 2 mT. They hypothesize that these effects are the result of the action of EFs induced in the medium by the MFs rather than direct action of the MFs on the cells.

    Motivated by suggestions in their earlier studies that 30-Hz EFs of about 1 mV/m countered the osteoporosis normally associated with bone disuse in experimental animals, McLeod and colleagues (1993) studied the effects of large MFs (about 2 mT) on cell proliferation and alkaline phosphatase activity of bone-related cells in vitro. In the entire study, involving several combinations of exposure time and cell plating density, three statistically significant results were reported: cells at one plating density exposed for 72 h had a 20% ± 10% (mean ± SE) lower proliferation rate, alkaline phosphatase activity in those cells increased, and cells at a higher plating density exposed for 12 h also had higher alkaline phosphatase activity. Although many individual samples were pooled to obtain the statistically significant end points, the investigators did not perform a separate study to confirm their findings. A related study (McLeod, table 2.4a) funded by EMF-RAPID found reduced alkaline phosphatase activity in another line of osteoblast-like cells.

    The general report of the McLeod EMF-RAPID project describes two exposure systems. One produces MFs, which of course induce EFs in samples placed within a solenoid. The other produces pure EFs by way of electrodes introduced into the sample media. Although pure EFs could easily be used to test directly the suggested physical mechanism of the action of MFs in these effects, no report of such tests is described in the materials supplied to the committee. If the hypothesis is correct, biologic effects can occur at EFs as small as 1 mV/m. The general report briefly mentions a study of effects of pure EFs on the orientation of cells. However, a paper in press by Lee and McLeod (In press) describes only the use of MFs in this work. Rubin and colleagues (1996) report inhibited proliferation of osteoclast cells. However, the effect is lower by only 8% at 30 Hz than at 60 Hz, whereas the EF was lower by half.

    In view of the apparent inconsistencies and/or small magnitudes of these reported effects, it will be necessary to have both internal and independent confirmation before the results can be used to guide animal studies, which would be necessary before evaluation of the implications for human health effects.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.4a— EF or MF Effects Reported in vitro, Information Sufficient to Calculate Magnitude of Effect

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Magnitude of effect

    Rationale

    Aaron

    Rhode Island Hospital

    MF effects on chondrogenesis in developing bone cells (in vivo/in vitro study)

    0.1 mT, 7 d for 7 h/d

    Increased glycosaminoglycans in days 7 and 9 but not days 3, 5, and 11; 60-Hz field accelerates chondrogenic differentiation and synthesis of cartilage

    1995

    ~2

    To test hypothesis that MF exposure produces alterations in endochondral ossification

    Blank

    Columbia Univ.

    MF effects on cytochrome oxidase function

    60 Hz, 0–10 µT; exposure duration not provided

    Reaction of cytochrome C with ascorbate is accelerated by MF exposure when basal rate of reaction is low (Blank and Soo 1998)

    1997

    ~2

    Use of cytochrome oxidase-ascorbate reaction rates as a measure of stress response to MF exposure

    Goodman

    Columbia Univ.

    MF and copromotion of neoplastic transformation using C3H 101/2 cells

    0.8–800 µT for 4–60 min and 1–7 h

    Activation of transcription factor enhanced; cells undergoing neoplastic transition are more sensitive to MFs than normal cells; cells undergoing suppression or induction of neoplastic transformation display more pronounced response (in gene expression) to intermittent MF exposures

    1997

    Insufficient data

    To test hypothesis that intermittent and transient MFs act as copromoter in carcinogenesis

     

     

    8 and 80 µT for 5–40 min

    Increases in heat shock protein in human breast cancer cells (Han and others In press)

    Up to 5

     

     

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Magnitude of effect

    Rationale

    Goodman (cont.)

     

    8 µT for 20–40 min

    Increased protein-DNA binding (Lin and others 1998a)

     

    Up to 10

     

     

    8 µT for 20 min

    Myc-mediated transactivation of heat shock protein (Lin and others 1998b)

     

    ~3

     

    Liburdy

    Lawrence Berkeley National Laboratory

    MF effects on intracellular calcium content

    100 µT, 60 Hz plus 40 µT DC

    Cells in MFs take up more calcium than controls after activation with anti-CD3

    1994

    2

    To test hypothesis that specific AC-DC field combinations National increase or decrease calcium signaling in mitogen-activated thymocytes according to Lednev parametric theory (Lednev 1991)

    McLeod

    State Univ. of New York

    Effects of EFs on bone cells in vitro

    > 100mV/m

    Bone cells show dose-response with threshold near 100 mV/m; transformed and nontransformed cells respond differently

    1993

    Insufficient data

    Hypothesis that magnetic fields act indirectly on cells through induced electric fields

     

     

    2.5 mT (1 mV/m), 30 Hz for 4–64 h

    McLeod gives example of about 20% reduction in alkaline phosphatase activity after 16 h exposure; evidence of EF versus MF effect not clear (Note: McLeod (McLeod and others 1993) showed increased alkaline phosphatase activity)

     

    Insufficient data

     

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Magnitude of effect

    Rationale

    McLeod (cont.)

     

    0.7 mT (0.2 mV/m) for 24 h

    Exposed cells showed changes in shape (Lee and McLeod In press)

     

    ~0.1 length, 0.2 area

     

     

     

    1.6 mT, 0.5 mV/m, 30 Hz; 1 mV/m, 60 Hz; for 7 d

    Rubin (Rubin and others 1996) reports inhibited proliferation of osteoclast cells; effect is lower by only 8% at 30 Hz than at 60 Hz although EF was lower by half

     

    ~0.7

     

     

     

    1.8 mT, 0.6 mV/m, 30 Hz, 12 and 72 h

    McLeod (McLeod and others 1993) reports increased alkaline phosphatase activity in cells plated at high density, but not in cells at low plating density

     

    0.5

     

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.4b lists project summaries that report in vivo MF effects and contain sufficient information to estimate magnitude of effect.

    Behavioral experiments conducted by Lai (1996) indicated that exposure to a 0.75-mT 60-Hz MF for 45 min immediately before training in a 12-arm radial maze retarded initial training but not asymptotic performance. In another experiment, adverse effects on Morris water-maze performance were observed (Lai and Carino 1998). In these experiments, the effects of several MF intensities and duration were assessed. These results, suggesting interference with memory, are potentially important. The committee believes that evaluation of potential health effects other than cancer and birth defects is appropriate. Other work by those and other authors also suggests that strong MFs can affect neurologic mechanisms and produce slight behavioral alterations. If such effects are confirmed, the public-health implications of small changes in performance of laboratory tasks caused by acute exposure to very strong MFs are unknown. Lai also reported in this project that small changes in performance of laboratory tasks were associated with MF-reduced high-affinity choline uptake in the frontal cortex and hippocampus of rats; opiate-receptor antagonists eliminated the effect (Lai and Carino In press). The data suggest an intensity times duration interaction; no effects were observed at 1 h and less than 2 mT, or at 1 mT and less than 1.5 h (Lai and Carino In press).

    In another project of Lai (Lai and Singh 1997), rats were exposed to 0.1, 0.25, or 0.5 mT and 60 Hz for 2 h, and then DNA-strand breaks were measured in isolated brain cells. Exposure to 0.01 mT for 24 or 48 h induced strand breaks, again suggesting an (intensity x duration) dose metric. The finding of single- and double-strand DNA breaks after MF exposure is highly controversial. The energy in ELF MFs is very low and the energy deposited will not break chemical bonds. DNA strand-breaks occurred at a maximum level approximately 4 h after MF exposure. This fact suggests that the breaks were not induced directly by the MF exposure, but occur due to secondary processes. Lai observes that some DNA damage is a consequence of free-radical formation, a normal process of many metabolic events (Lai and Singh 1997). The working hypothesis is that MF exposure increases the very brief duration of free radical survival, thereby increasing the resulting damage. This hypothesis has some support in magneto chemistry with very high MF strengths, but its relevance to biologic systems at lower field strengths is at best uncertain. The authors also report DNA-protein and DNA-DNA cross-linking after MF exposure (Singh and Lai 1998). As a whole, these observations could be seminal or wrong. The experiments provide an example of the dictum, "extraordinary claims require extraordinary proof". If further replication studies are funded, the Lai and Singh studies could be candidates for consideration.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.4b—MF Effects Reported in vivo, Information Sufficient to Calculate Magnitude of Effect

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Magnitude of effect

    Rationale

    Lai

    Univ. of Washington

    MF effects on behavioral and cholinergic activity in brains of rats

    0.75 mT for 45 min

    2 mT for 1 h

    MF effect on cholinergic system induced spatial "working" memory deficit (Lai 1996)

    Radial arm maze (Lai and Carino 1998)

    1994

    2

    1

    Suggestion by this group that MFs affect cholinergic mechanisms in brain

     

     

    0.5 mT for 3 h

    2 mT for 1 h

    MFs reduced high-affinity choline uptake in frontal cortex and hippocampus in two experiments; opiate-receptor antagonist eliminated effect (Lai and Carino In press)

     

    2

    1

     

     

     

    1 mT for-90 min

    Reduced cholinergic activity (Lai and Casino In press)

     

    1

     

    Lai

    Univ. of Washington

    Evaluation of DNA-strand breakage and DNA cross-links in rat brain after MF exposure

    0.5 mT for 2 h

    0.5 mT for 2 h

    Lai and co-workers report DNA strand breaks (Lai and Singh 1997)

    DNA-DNA cross-links, and DNA-protein cross-links (Singh and Lai 1998) in brain cells isolated from rats exposed to MFs in vivo

    1997

    2

    1

    PI hypothesis that MF exposure affects free-radical kinetics and results in DNA-strand breaks and cross-links

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.5a lists project summaries that report in vitro experiments conducted as efforts to replicate previous reports of EMF effects.

    Most of the outright replications of in vitro studies shown in table 2.5a were straightforward, and most turned out to be negative. Some are rather striking. In an original study by Rodemann and others (1989) one of the strongest published effects of MFs (magnitude of about 10) was reported, and the 6-mT fields used in the study were large. Nuccitelli attempted to replicate the work of Rodemann indicating that MFs affect protein synthesis in fibroblasts and keratinocytes. He also attempted to replicate a report by Goodman and Blank (1998) that MFs induce heat-shock proteins in HL-60 cells. Nuccitelli did not observe effects reported by Rodemann and by Goodman, even though the experimental conditions were carefully replicated.

    A number of EMF-RAPID projects attempted to replicate positive studies on gene expression—all with negative results. Two studies by Balcer-Kubiczek investigated various aspects of gene expression which have been of interest since earlier studies (Goodman and Shirley-Henderson 1990) suggested changes in gene expression after MF exposure. The studies of MF effects on expression of 11 genes conducted by Balcer-Kubiczek involved the use of northern blots and a technique based on the polymerase chain reaction (PCR). With those techniques, no MF effects on expression of these genes were noted in a series of four experiments. At the time of the Balcer-Kubiczek study, PCR was perhaps the technique of choice because of its high sensitivity for detection of changes in messenger levels in cells responding to extracellular stimulation. The rapid development of new chip technology and the use of new genomic data on gene expression could facilitate further studies of this nature. Studies like those carried out by Balcer-Kubiczek might have further value if replicated with the new technology.

    A study by Lieberman noted no MF effects on gene expression, failing to reproduce preliminary experiments performed in Goodman's laboratory. The Lieberman studies on yeast transcription are so briefly described that one cannot be certain about whether the measurements were sufficiently sensitive to detect subtle changes.

    Owen looked at expression of the c-myc proto-oncogene in promyelogenous leukemia cells (HL-60) and examined omithine decarboxylase (ODC) activity in mouse L929 cells (Cress and others, In press). In an attempt to replicate the expression of c-myc in HL-60 cells reported by Goodman and others, the PI attempted to use serum lots, cell types, and procedures as used by Goodman and co-workers. One of the core exposure facilities was used in some of the studies. MF exposure did not increase c-myc expression (Owen 1998). No statistically significant effects on ODC activity were observed.

    Miller investigated oncogenic transformation after MF exposure. No effect was seen in the 10T1/2 transformation system; preliminary indications of copromotion were noted in a study with late gestational Syrian hamster fetuses exposed in utero.

    In an attempt by McDonald to replicate the induction of heat-shock proteins in human lymphoblasts, the PI was unable to show that the expression was a function of exposure to MFs as reported by Goodman and others.

    In another published study, Saffer and Thurston (1995), using great care in their replication efforts, were also unable to show that the c-myc proto-oncogene expression in HL-60 was altered by exposure to 60-Hz EMFs. Differential-display PCR did not indicate that any other genes in HL-60 were affected. Using the JB6 cell line, already

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    initiated but not fully transformed, Saffer was also unable to demonstrate transformation over a wide range of MF exposures (Saffer and others 1997).

    McCormick also attempted replication of the findings of Goodman and Henderson. In two replication studies conducted independently by different investigators in the McCormick laboratory, no MF-induced increases in c-myc expression in HL-60 cells were noted, either in basal conditions or when stimulated by TPA. McCormick also reports that exposure to MFs for 20 min to 24 h had no effects on cell proliferation or on expression of cancer-associated genes (c-myc, p53, or HER-2/neu) in either estrogen-receptor-positive or -negative human breast epithelial cells. MF exposure also had no interactive effects with c-myc expression stimulated by TPA or p53 expression stimulated by mitomycin C.

    Williams, in his report outlining preliminary work on gene expression, notes that HL-60 cells do not appear to up-regulate c-myc mRNA in response to the five MF exposure conditions he tested. Williams also was unable to replicate a previous report of up-regulation in c-myc mRNA in the human T-cell leukemic cell line CEMCM3 after MF exposure. An investigation of MF effects on cellular responses to DNA damage was also negative.

    A focused replication effort by S.C. Miller of previous work by Uckun and others (Uckun and others 1995) using the DT-40 cell line and selected DT-40 mutants from the Uckun laboratory showed no effect on inositol 1,4,5-phosphate (IP3) production with 0.1-mT 60-Hz MF exposure. Miller failed to find any effects on NFkB- or AP-1-dependent reporter-gene expression in a human leukemia cell line. Miller also reports a failure to find an effect on phosphotyrosine profiles after MF exposure.

    The project summary by Hui and colleagues presents an inquiry into the response of lymphoblastoid cells to 0.1- to 0.4-mT MF exposure. Attempts to reproduce the results of Phillips (Phillips and others 1992), who reported that the expression of c-fos and c-myc proto-oncogenes was affected in lymphoblastoid cells exposed to 0.1-mT 60-Hz MFs, were unsuccessful even after exhaustive attempts at replication. Quantification of proto-oncogene expression was normalized to the expression of a housekeeping gene, G3PDH, a step not taken in the original experimentation by Phillips and co-workers. The investigators also used a transformation model (INIT C3H 10T1/2 cells transformed with methylcholanthrene but controlled with retinyl acetate) to test for promotional effects of EFs and MFs. No promotional effects were found. Hui and co-workers also noted that exposure to 0- to 100-mV/cm EFs does not produce changes in internal calcium concentrations. In summary, Hui did not find any effects that could be attributed to MF exposure regarding gene expression, transcription rates, transcript levels, c-myc levels, proliferation rates of initiated cells, or intracellular Ca2+ concentrations in this careful study.

    Lotz conducted studies (at the NIOSH regional exposure facility) to replicate the experiments of Lindstrom and colleagues (1995a, b) who reported that transient changes in intracellular free-calcium concentrations were induced in the human leukemic Jurkat lymphocyte cell line by exposure to a weak MF at 50 Hz. In the intracellular-calcium study, no significant differences were found in incidence of Ca2+ concentration transients during exposure to a 50-Hz, 0.15-mT MF. Another replication by Lotz attempted to confirm the findings of R.W. West (West and others 1994, 1996) that exposure to ELF MFs significantly increases colony-forming efficiency in soft agar, an event associated

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    with neoplastic transformation in these cells (anchorage-independent proliferation). In the cell-proliferation study, the NIOSH data indicate that exposure of JB6 cells to a 0.1-or 1.0-mT, 60-Hz field does not alter anchorage-independent proliferation, and exposure does not increase the effect of TPA or alter anchorage-independent proliferation. In the Lotz replication studies, the importance of continuing consultation with the original investigators was apparently recognized. Collaboration with the original investigators appears to have been a part of the two replication efforts, and extensive efforts were made to achieve close replication of the original experimental conditions.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.5a—ln vitro Experiments Conducted as Efforts to Replicate Previous Reports of MF Effects

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Balcer-Kubiczek

    Univ. of Maryland at Baltimore

    MF effects on gene expression in various cell lines in vitro in relation to exposure parameters

    Typically 2 mT for 3 h

    No MF effects on expression of 11 genes in a series of four different experiments

    1994

    Historical interest in MF and gene expression based on results of Goodman and others

    Balcer-Kubiczek

    Univ. of Maryland at Baltimore

    MF effects on gene expression in vitro with PCR-based method

    2-mT, 60-Hz square wave for 3 or 24 h

    When mRNAs in exposed and control HL-60 cells were compared, one differentially expressed cDNA clone was found among. 1,000 cDNAs (no internal confirmation of observation)

    1997

    To test hypothesis that exposures to MFs with higher-frequency components ''alter expression of immediate early genes"

    Hui

    Roswell Park Cancer Institute

    Effects of MF exposure on expression of proto-oncogenesin lymphoblastoid cells

    0.1 mT, 60 Hz; duration not reported

    Failure to replicate observation that MF exposure of lymphoblastoid cells affects expression of c-fos and c-myc proto-oncogenes or intracelluar Ca2+ concentration

    1994

    Attempt to replicate results of Phillips (Phillips and others 1992) indicating that MF exposure of lymphoblastoid cells affected expression of c-fos and c-myc proto-oncogenes

    Lieberman

    Columbia Univ.

    MF effects on gene expression in yeast

    80 µT, 20 min

    No MF effect on gene expression

    1997

    Lieberman observation in preliminary experiments in Goodman's laboratory that selected genes were turned off in cells exposed to MFs

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Lotz

    National Institute for Occupational Safety and Health

    MF effects on transient changes in intracellular free calcium in human leukemic cell cultures

    0.15 mT, 50 Hz for 8–16 min

    MF effects reported by Lindstrom not found

    1995

    Attempt to replicate results of Lindstrom (Lindstrom and others 1993), who reported MF induction of transient changes in intracellular free calcium (Lindstrom and others 1995a)

     

    Anchorage independent proliferation of promotion-sensitive JB6 cells in soft agar (transformation assay)

    0.1 and 1.0 mT for 10-14 d

    MF effects reported by West not found

     

    Anchorage independent proliferation of promotion-sensitive JB6 cells in soft agar (West and others 1994; Lindstrom and others 1995b; West and others 1996)

    McCormick

    IIT Research Institute

    MF effects on expression of c-myc gene in HL-60 promyelocytic leukemia cells

    1–1,000 µT

    No MF effects on c-myc expression in HL-60 cells in two replication studies by different investigators in laboratory

    1994

    Attempts to replicate, in two independent studies, expression of c-myc in HL-60 cells as reported by Goodman and Shirley-Henderson (1990)

    McDonald IIT Research Institute

    MF effects on heat-shock protein expression in human cell lines

    0.01, 0.1, and 1 mT for 1, 4, or 24 h

    No MF effects observed

    1997

    Evaluation of possible MF effects on stress responses as judged by induction of heat-shock proteins

    Miller, R.C.

    Columbia Univ.

    Oncogenic transformation in C3H 10T1/2 cells exposed to MFs, TPA, and x rays

    0.2 and 1.0 mT, 24 h., TPA at 0.1 mg/ml for 8 wk, 3-Gy x rays

    No effect of magnetic field on C3H 10T1/2 cell transformation

    1994

    Interest in MF exposure and carcinogenesis; transformation models used here are thought to be indicators of carcinogenic potential

     

    Transformation in Syrian hamster embryos exposed in utero to MFs, TPA, and x rays

    2.5 mT, 48 h, TPA at 0.1 µg/ml, 1-Gy x rays

    Indications of copromotion in late-gestational-age embryos

     

     

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Miller, S.C.

    SRI International

    MF effects on IP-3 production in DT-40 cell line

    0.1 mT, 60 Hz for 24 h

    Failure to find MF effect on IP-3 production as reported by Uckun

    1994

    Careful replication of MF effects on IP-3 production reported by Uckun (Uckun and others 1995)

    Nuccitelli

    Univ. of California, Davis

    MF effects on protein synthesis in human keratinocytes and fibroblasts

    8 mT, 20 and 60 Hz for 6 h/d for 7, 14, or 21 d

    Failure to find increase in protein synthesis as reported by Rodemann and by Goodman

    1994

    Exact replication of study by Rodemann (Rodemann and others 1989), who reported one of strongest published effects of MFs (magnitude, 10), an increase in protein synthesis rates in human fibroblasts

     

    MF effects on heat-shock proteins (HSPs) in human keratinocytes

    0.1 mT for 5 min, 20 min, 2 h, and 24h

    No effects on HSPs observed

     

    Reports from Goodman of effects on HSPs (Goodman and Blank 1998)

    Owen

    Food and Drug Administration

    MF effects on gene expression in HL-60 promyelogenous leukemia cells and ornithine decarboxylase activity in mouse L929 cells

    6 µT, 60 Hz for 20 min or 6 µT, 60 Hz for 4 h

    MF exposure did not increase c-myc expression, and no statistically significant effects on ODC activity were observed

    1994

    Attempt to replicate expression of c-myc in HL-60 cells as reported by Goodman and other investigators (Byus and others 1987; Goodman and others 1989; Litovitz and others 1991; Goodman and others 1992; Lin and others 1994; Lin and Goodman 1995; Litovitz and others 1995; Jin and others 1997; Litovitz and others 1997)

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Saffer

    Battelle Pacific Northwest National Laboratory

    MF effects on gene expression in HL-60 cells

    6–1,000 µT for 20–60 min

    No MF effects on c-myc expression; no indication of increased gene expression from differential-display PCR (Saffer and Thurston 1995); a major replication study involving 15 tests of claims of effects varying by factors of 1.3–4.5

    1994

    Attempt to replicate expression of c-myc in HL-60 cells as reported by Goodman and other investigators (Byus and others 1987; Goodman and others, 1989; Goodman and Shirley-Henderson 1990; Litovitz and others 1991; Goodman and others 1992; Phillips and others 1993; Litovitz and others 1995; Uckun and others 1995; Jin and others 1997; Litovitz and others 1997)

     

     

    100–1,000 µT for 20–60 min

    No indication of cell transformation in initiated JB6-cells cells (Saffer and others 1997)

     

    Attempt to replicate indications of MF promotional effect on initiated JB6 (Litovitz and others 1991; Fitzsimmons and others 1992; Phillips and others 1993; West and others 1994; Uckun and others 1995; Litovitz and others 1995; West and others 1996)

    Williams

    Johns Hopkins Univ.

    MF effects on gene expression and interaction of fields with mutagens in HL-60 and lung-cancer cells

    100 µT, 60 Hz for 20 min; 100 µT, 60 Hz for 72 h

    No reproducible patterns of gene expression observed after any MF exposure investigated

    1994

    Attempted to replicate expression of c-myc in HL-60 cells, as reported by Goodman and co-workers (1990)

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.5b lists project summaries that report in vivo replication studies.

    In general, the in vivo replication studies (table 2.5b) funded by EMF-RAPID did not confirm the positive results of the original experiments. Two replication studies investigated the possibility that MFs act as promoters in carcinogenesis. The study by Anderson and co-workers attempted to replicate the results of Loescher and colleagues, who reported that 50-Hz MF exposure promoted mammary-tumor development in Sprague Dawley rats given dimethyl-[a]benzanthracene (DMBA); melatonin concentrations also were studied. Four papers by Loescher and colleagues, (Loescher and others 1993; Mevissen and others 1993; Loescher and others 1994b; Baum and others 1995) describe their work. Promotional effects and melatonin suppression were observed in some of their experiments.

    To evaluate the potential of 50- or 60-Hz MFs to promote breast cancer in female Sprague Dawley rats treated with DMBA, several experimental protocols were followed by Anderson's group. In each of the protocols, groups of 130 rats were used for each exposure level of 0.1 mT at 60 Hz and 0.1 and 0.5 mT at 50 Hz, with and without administration of DMBA by gavage in sesame oil. Animals were exposed to MFs for 13 wk or 26 wk, including sham-exposed and vehicle-control groups. During the MF exposure period, all animals were evaluated for mammary-gland tumors by palpation; at the end of the MF exposure period, tissues from all animals were evaluated histopathologically. The first 13-wk, 20 mg DMBA study and the 26-wk, 10 mg DMBA study showed that 90% of the rats developed multiple mammary carcinomas; this limited the sensitivity to a possible promotional effect of MFs. Therefore, the second 13-wk study was carried out at a reduced DMBA dose of 8 mg. In this study, 40% of the animals developed mammary cancers, thus providing enough sensitivity to detect effects reported by Loescher. In addition, a 26-wk study With 10 mg of DMBA was completed in which there was no evidence of early onset of mammary gland tumors as a result of magnetic field exposure.

    This project, using a proven and well-established protocol, found no evidence of any promotional activity of MFs of 0.1 and 0.5 mT at 50 Hz or 0.1 mT at 60 Hz in the Sprague Dawley rat. The study also found no evidence of a melatonin-suppression effect. Possible differences in the replication study include the age of the rats and DMBA purity; the DMBA lot at Battelle produced tumors at a lower concentration than the lot used by Loescher and colleagues. Independent evaluation of the weak positive promotional results reported by Loescher and others was an important objective of the EMF-RAPID program. The study by Anderson and colleagues was one of several EMF-RAPID biology projects funded by a contract mechanism. Because the contract mechanism was used, a complete peer-reviewed report (NTP 1998a) for Anderson's project was available to the committee at the completion of the EMF-RAPID program. The second group of investigators (Byus and others 1987) received support to test claims that MFs and TPA can act as copromoters of DMBA-initiated epidermal tumors. Two Sencar mouse experiments involving DMBA initiation, TPA promotion, and 2-mT field exposure were completed; they yielded contradictory results. The PI is convinced that the best chance of detecting a copromotional effect of MFs occurs with low doses of TPA, at which tumor response is low and statistical power is highest.

    The difference between groups was not statistically significant until between weeks 30 and 43. The PI feels that this "late" effect is important and possibly reflects the

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    response of a subset of tumor types. However, experiment 2 did not show a clear copromotional effect. The author discusses possible reasons for the different outcomes, emphasizing that in experiment 2 the overall tumor response to the same dose of TPA was greater. Also, the response in experiment 2 was "early" rather than "late". In both experiments, ornthine decarboxylase (ODC) was measured in a variety of tissues; no MF-related increases in ODC were observed. The report supplied to the committee on this project is difficult to evaluate, but it does not establish robust effects.

    Three projects tested various aspects of the relationship between MF exposure and melatonin concentrations in humans. A preliminary reanalysis of existing data (Burch and others 1998) by Yost reports a statistically small effect (P < 0.04) on melatonin concentrations at night in electrical-utility workers. In an analysis of one of their earlier studies of human subjects, Graham and others (1996) found that melatonin concentrations in men with low pre-existing melatonin were affected by exposure to large MFs under controlled conditions in a laboratory setting. Under EMF-RAPID sponsorship, they tested these findings in a replicate experiment with men and in a similar experiment with women as subjects; both experiments produced negative results.

    Reiter conducted a series of about 12 experiments on melatonin in rats using the Yellon exposure paradigm (Yellon 1994), which involves a single 30-min exposure to 60-Hz and 0.1 mT beginning 2 h before lights off. The Reiter experiments used rats as the animal model; the Yellon studies used a djungarian hamster model. Species differences in melatonin responsiveness to MF exposure are a possibility. Reiter reports uniformly negative results. Later, he conducted five experiments with the exposure paradigm of Selmaoui and Touitou. This protocol involves 12 h of exposure, beginning in light and extending into darkness; again, melatonin was assessed on the first night of exposure. This also was an acute experiment, ignoring evidence from rats that the melatonin-suppression effect develops over days to weeks of chronic day-night exposure (Wilson and others 1986; Kato and others 1994). Selmaoui and Touitou (1995) had reported weak evidence of a melatonin-suppression effect; Reiter reports uniformly negative results with the Selmaoui and Touitou exposure paradigm.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Table 2.5bIn vivo Experiments Conducted as Efforts to Replicate Previous Reports of MF Effects

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Anderson

    Battelle Pacific Northwest National Laboratory

    Effect of MFs as promoters of DMBA-initiated mammary-tumor development in Sprague Dawley rats

    0.1 and 0.5 mT at 50 Hz, 0.1 mT at 60 Hz, 13 and 26 wk

    Anderson and colleagues unable to replicate reports by Loesher and co-workers that MF exposure promotes mammary-tumor development in DMBA-treated rats (NTP 1998a)

    1996

    Attempt to replicate observation by Loescher and co-workers that MF exposure promotes mammary-tumor development in DMBA-treated rats (Mevissen and others 1993; Loescher and others 1994a; Loescher and others 1994b; Baum and others 1995)

    Byus

    Univ. of California, Riverside

    MFs and TPA as copromoters of DMBA-initiated epidermal cancer in Sencar mouse

    2 mT

    One experiment indicated significant copromotional effect on skin carcinogenesis after 30 wk of treatment; second experiment did not show copromotional effect

    1992

    Positive indication of copromotion in ODC transgenic K2 mice (Stuchly and others 1992)

    Graham

    Midwest Research Institute

    MF effects on melatonin and immunity in humans

    20 µT

    One study failed to confirm hypothesis that MFs suppress nocturnal melatonin in men with pre-existing low melatonin; second study failed to show MF effect on melatonin in women

    1994

    Replication of previous observation (Graham and others 1996) that, in men with low existing melatonin, MF exposure further suppressed production

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    PI

    Topic

    Exposure

    Result

    Funded (FY)

    Replication

    Reiter

    Univ. of Texas Health Science Center

    MF effects on pineal melatonin in rats

    0.025, 0.05, and 0.1 mT continuously and intermittently for 12 h

    No statistically significant effects on pineal melatonin in 17 experiments conducted with Yellon or Selmaoui and Touitou acute exposure protocols

    1994

    Attempt to verify MF effects on melatonin as mechanism of MF health effects with multiple acute MF-exposure protocols

    Yost

    Univ. of Washington

    MF effects on melatonin in utility workers

    Environmental fields of 0.1–0.3 [.muT measured with personal exposure meters for reanalysis of data of Butch and colleagues (1998)

    Trend of decreased nocturnal melatonin after increased MF exposure during workday; weaker correlation when compared with h mean exposures, suggesting a confounder; results have borderline statistical significance

    1997

    Reanalysis of data from study by Burch and co-workers reporting an association between MF exposures of utility workers and lowered melatonin (Butch and others 1998)

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Biology Summary

    The first three categories of biology projects are of limited use for the evaluation of health effects at the present time. The majority of the information was provided to the committee in the form of 2–3 page project summaries. It was not always clear whether the work was hypothesis driven or "screening for effect" investigations. If published in peer-reviewed journals the hypothesis-driven studies could have value even if they report negative results. Category 4 projects provided sufficient information, either in the project summaries, or in solicited material sent to the committee, to estimate the magnitude of the reported effect. The reports of effect in this category are unconfirmed. Category 5, the replication category, is an important classification in the committee's judgement. This final category includes a wide scope of replication studies, ranging from "exact replications" to attempts to replicate general effects (transformation for example). The results of these replication studies are almost entirely negative.

    Discussion

    From a technical perspective, the EMF-RAPID program has helped incrementally to answer the basic question of whether environmentally relevant power-frequency MFs can produce biologic effects. The engineering studies underscore the fact that time-averaged MF exposures in a wide range of occupations are remarkably similar. That has implications for the interpretation and design of epidemiologic investigations. The literature on laboratory studies of this subject is full of conflicting claims. The only responsible way to deal with the situation is to subject the most important positive reports to multiple independent replication. EMF-RAPID made a substantial start on replication, which is an important contribution. The replications conducted under the program have had almost entirely negative results and thus have reduced the credibility of many of the claims of biologic effects of power-frequency MFs.

    If it can be shown unequivocally that low-level power-frequency MFs do produce biologic effects, and if the effects are robust enough for the scientific community to reproduce the phenomena routinely, the underlying biophysical mechanism will eventually be established. However, the EMF-RAPID program has shown that much of the literature on MF bioeffects is questionable, in that it is not easily replicated. No finding from the EMF-RAPID program substantially contradicts the conclusions of the earlier National Research Council committee report Possible Health Effects of Exposure to Residential Electric and Magnetic Fields (NRC 1997).

    Information-Dissemination Projects

    The Energy Policy Act of 1992 specified that the EMF-RAPID program should "provide for dissemination of information . . . to the public". Two of the four objectives of the National Electric and Magnetic Field Research and Communication Program: Draft Strategic Plans5 were not met:

    5  

    For communication objectives see page 16 of this report

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
    • "Plan, support, and conduct communication research." The committee is unaware of any communication research funded under EMF-RAPID.

    • "Encourage communication from public decision-makers to those who plan scientific studies". The committee found little evidence of such encouragement, although it is not clear what was intended by the objective, and the interagency committee might be seen as fulfilling this aim.

    Information-Dissemination Booklets

    Two booklets were published as part of the EMF-RAPID communication effort. The first, Questions and Answers About EMF: Electric and Magnetic Fields Associated With the Use of Electric Power (DOE 1995) was reviewed in the committee's interim report. The present EPACT Committee concurs with the original assessment on page 20 of this report. According to information provided by NIEHS, about 180,000 copies of the booklet have been dispersed, half going to utilities for distribution to customers and the remainder going to state and local governments and to fill requests from the public. An additional 20,000 copies of the booklet were printed in Spanish; about 16,000 copies have been dispersed. The committee, in its interim report, concluded that more booklets of this sort should be published and suggested that it would be useful to prepare a more comprehensive guide, which would include biologic effects observed in the laboratory and an extended reference section for the more technically interested reader.

    A second booklet, Questions and Answers EMF in the Workplace, was produced by EMF-RAPID. This booklet included some of the same information as the first booklet, but it also included chapters on human health studies (epidemiology) and biologic research (animal and cell biology). Information was presented on MF measurements, and examples of MF exposure in the workplace were included. It identifies other information sources and includes an extended reference section. The booklet was printed in the United States and Canada, and NIEHS has estimated that 65,000 copies were distributed in the United States. It meets the recommendations of the interim EPACT Committee report.

    EMF InfoLine

    The Environmental Protection Agency (EPA) initially operated a toll-free telephone EMF-information line jointly funded by EPA and EMF-RAPID. In 1998, oversight of the line was assumed by NIEHS. The information line responds to public inquires about both 60-Hz MFs and radio-frequency radiation, and it refers callers to appropriate resources. The persons who answer calls also take orders for the two booklets described above. Calls to the line seem to be handled responsibly. The EPACT Committee has no information on funding support for this seemingly useful activity.

    EMF-RAPID Web Site

    The NIEHS EMF-RAPID Web site (http://www.niehs.nih.gov/emfrapid/home.htm) contains a number of documents available to any member of the public who has access to the Internet. The number of requests for downloads averages 161 per day. For the period

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    March 1, 1997, to June 30, 1998, a total of 78,128 files were downloaded from the site. Items are added and occasionally removed from the site, but a menu existing in August 1998 illustrates the type of information that is available:

    • Overview and program focus: a one-page description of the program.

    • Program organization, staff, and components.

    • EMF annual reports: NIEHS reports for years 1994–1996 with updates for 1996 and 1997.

    • EMF-RAPID interim report to congress, December 1995.

    • Research information: short (two or three page) project summaries of the 61 projects funded by EMF-RAPID and some projects funded by other means. Some of the project summaries included on the Web site have many of the same shortcomings as those in the project summary books provided to the committee. Data sometimes were incomplete, absent, or not current. Occasionally, cited figures and tables are not present. It sometimes appears that publications cited as resulting from projects predate the projects or are not related to them. Some funding information and contact information on the principal investigators are provided.

    • EMF regional magnetic field exposure facilities: brief descriptions of the four facilities designed to provide uniform MF exposures for the EMF-RAPID program, links to the four institutions (Food and Drug Administration, National Institute for Occupational Safety and Health, Oak Ridge National Laboratory, and Pacific Northwest National Laboratory), and an e-mail contact for each program.

    • EMF-science review symposia and meetings: information from the three NIEHS symposia and the Department of Energy engineering symposium. The discussion of the DOE engineering component was fragmentary and incomplete at the time this report was written.

    • Questions and Answers about EMF: this booklet can be accessed directly or downloaded from the Web site.

    • EMF in the Workplace-Questions and Answers: can be accessed directly or downloaded from the site.

    • EMF measurements database: ''The purpose of this project is to make measurements of EFs and MFs publicly available". A small amount of information from the engineering symposium is available here. Three data sets had been entered at the time of committee review. The database is not judged to be user-friendly.

    • Other MF information sources: directs the users to other sources MF information.

    • Working-group report: available in PDF and HTML versions.

    Miscellaneous

    An EMF "sourcebook" was created in a hard copy version and on the Internet. The hard copy version of the sourcebook consists of materials similar to those appearing on the EMF-RAPID Web site (described previously). Two travel grants were awarded to allow representatives from citizen groups concerned about EMFs to attend the 1995 annual DOE contractors' meeting in Palm Springs, CA.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Summary

    Regarding a third objective of the draft strategic plan—"improve coordination and communication with the national and international scientific community. Provide referral services . . ."—the scientific symposia (discussed in the next section of this report) did meet the objective of improving communication among the scientific community. The committee finds the scientific and technical quality of the information to be acceptable. The objective to "provide referral services" is partially met by the Web site described above, and referral services were also provided by the EMF-RAPID information line. If data were regularly entered into the database, progress toward meeting this objective would be improved.

    Finally, the fourth objective of educating the public and others is addressed by many of the activities listed above. However, much of the material is in a format or a language directed at the technical community. The first booklet was written for the general public. The committee recommends that NIEHS work to make the Web site easily accessible for the general public.

    EMF Science-Review Symposia

    NIEHS organized three EMF science-review symposia that were intended to review the literature on several major power frequency magnetic field research subjects. The first covered theoretical mechanisms and in vitro research, the second covered epidemiologic research, and the third covered clinical and in vivo laboratory research. The meetings were open to the public. The "breakout group" reports of the meetings are available as NIEHS publications (NIEHS 1997; NIEHS 1998b,c) and also are available to the public on the EMF-RAPID Web site. The reports reasonably summarize the meetings. However, despite the hard work of many participants, the meetings did not constitute a systematic, comprehensive review of the literature.

    The most important accomplishment of the three biology-review symposia might have been to educate newcomers brought into the risk-assessment process being considered by NIEHS. For example, discussion groups attempted to answer specific questions posed by NIEHS. Some of these questions were related to summaries of the state of the science, and other questions were related to hazard identification and risk assessment. However, on-site ad hoc efforts to review a selected subset of extensive and complex scientific literature in a few hours in a large public meeting did not provide an effective and satisfying product. Thus, the scientific value of these meetings is less than that of the 1997 National Research Council committee report (NRC 1997), the 1998 NIEHS working-group report (NIEHS 1998a), or other published reviews. Furthermore, with respect to communication among members of the bioelectromagnetics community, the three NIEHS biology review meetings were supplementary efforts added to the two prime scientific meetings, the DOE contractors' conference and the Bioelectromagnetics Society meeting, which have been held annually for at least 2 decades. The NIEHS working group did not use the three EMF science-review symposium booklets in a formal way. It is not known whether they will be used by NIEHS in the preparation of its final report.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    A fourth symposium on the engineering component of the EMF-RAPID program, sponsored by DOE, allowed principal investigators who had completed detailed engineering-project reports to present their methods and findings publicly, and discuss them with interested participants (NIEHS 1998d).

    EMF-RAPID Working-Group Report

    The working-group meeting, held June 16–24, 1998, in Brooklyn Park, MN, produced an NIEHS report titled Assessment of Health Effects from Exposure to Power-Line Frequency Electric and Magnetic Fields (NIEHS 1998a). A press release described the essential findings of the report, and the report was made available for public review (hard copy and CD-ROM available by mail) and placed on the EMF-RAPID Web site in several formats. A period for public review and comment was designated from August 10, 1998, through October 9, 1998. The public was encouraged to comment on the report by mail or in person at three locations: Washington, DC, on September 28, 1998; San Francisco, CA on October 1, 1998; and Chicago, IL, on October 5, 1998. A fourth opportunity for public comment occurred on the afternoons of September 14 and 15, 1998, at the annual EMF contractors' meeting sponsored by DOE in Tucson, AZ. Records of the public comments are available to the public at various sites in the United States.

    Under the EMF-RAPID program, NIEHS established the working group to assess health effects of exposure to power-frequency magnetic fields. The working group, consisting of 29 voting members, met on June 16–24, 1998, in Brooklyn Park, MN. Twelve of the participants contributed to first-draft documents before the meeting.

    As in the three biology symposia, the working group largely considered published findings. Papers and reports that had not been published but that provided enough detail, including results of in vivo studies funded by RAPID, were considered. Although this rule was not always strictly adhered to, it tended to eliminate current EMF-RAPID research from consideration or discussion. The NIEHS working group reviewed essentially the same epidemiology that was reviewed by the Research Council committee on Possible Health Effects of Exposure to Residential Electric and Magnetic Fields (NRC 1997), adding the literature accumulated from 1996 to 1998.

    The two reviews differed in a number of important ways. Perhaps the most important were the time available for arriving at the conclusions and the process of arriving at the wording of the conclusions. The Research Council committee functioned for several years and had intensive discussions over the course of many meetings. The NIEHS working group as a whole was operational for 10 d, and most of the time was devoted to arriving at the final language of the literature review. The discussions in which conclusions were reached occurred at the end of the meeting and were very limited in time. The Research Council committee developed its conclusions, after multiple discussions among the whole committee, in the form of a consensus report agreed to by all participants. The NIEHS working group was directed to follow the process used by IARC. The participants answer a set of predefined questions in successive votes. The questions cannot be modified during the process, and the weight of the participants' opinions is equal for all questions and votes, regardless of their disciplines and expertise. No effort was made to reach consensus nor to identify and explain differences in opinion.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    Much of the working group's time was spent in small groups as subcommittees worked to write specific sections of the literature review. Although plenary sessions were held, these usually were attended only by groups that wrote the text or by individuals from closely related fields of expertise.

    The process used by the Research Council committee involved long and repeated discussions in which the expertise of the participants could be considered in arriving at a consensus. The findings and conclusions were framed in ways that allowed a consensus to be developed. Furthermore, they reflected nuances based on the context of the weight of evidence that was discussed in many sessions in which all members took part. This negotiated consensus was a set of conclusions arrived at by all the participants after multiple sessions of open discussion. The process put a premium on the persuasiveness of the evidence and on the ability of participants of one discipline to persuade participants from other disciplines about the value of different lines of evidence.

    The value of the IARC-based process is its following of an established process used extensively in the evaluation of the carcinogenicity of hundreds of compounds. The IARC process leads to a definite result—the evaluation of the human carcinogenicity of an agent. Because an agent to be evaluated with the IARC process needs to be a suspect carcinogen and because the process is conservative in the prescribed steps, it is not surprising that IARC evaluations are extremely likely to result in a finding of possible carcinogenicity.

    The IARC process is guided by the epidemiologic evidence in humans which can be "sufficient", "limited" or "inadequate". Animal evidence can be "sufficient", ''less than sufficient", "limited", and "inadequate". The final characterization of the exposure can then be Group 1 "carcinogenic" (human:sufficient, animal:sufficient), Group 2A "probably carcinogenic" (human:limited, animal:sufficient), Group 2B "possibly carcinogenic" (human:limited, animal:less than sufficient), Group 3 "not classifiable" (human:inadequate, animal:inadequate or less than sufficient), and Group 4 "probably not carcinogenic" (human:evidence suggesting lack of carcinogenicity, animal:evidence suggesting lack of carcinogenicity) or (human:inadequate, animal:lack of carcinogenicity). The process does not recognize lack of carcinogenicity in animals except in Group 4, and that would require a finding that the human evidence was inadequate.

    Both reviews (NRC 1997; NIEHS 1998a) had the benefit of meta-analysis of epidemiologic findings, and much the same approach was used in both meta-analyses. The meta-analyses were carried out on the basis of published data; considerable differences existed in the design and execution of the studies. Characterization of the exposure to EMFs varies widely in different studies, and it is not possible at this time to identify the most relevant metric for characterizing exposure. The appropriateness of converting wire codes into assigned levels of MFs on the basis of the few simultaneous observations of wire codes and direct measurements in homes may be a questionable undertaking but it is necessary to link different studies. Many of the meta-analyses were based on categorical estimates of exposure; few analyses addressed exposure estimates of a continuous nature. The meta-analyses in both reports contain numerous cautions as to many inherent weaknesses, but they then proceed to present the combined results of a large number of analyses. One purpose of the meta-analyses is to see whether the combined statistical power of several studies provides more significant associations. The

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    meta-analyses have not increased the strength of the association, although one does get the expected increase in statistical significance.

    The Research Council committee report and the NIEHS working-group report reviewed much of the same epidemiology. The latter group had the ability to review literature published in 1996–1998, although no definitive or extraordinary epidemiologic studies were published during the 2-yr period. The conclusions are not greatly dissimilar, but the two processes resulted in differently worded statements. The Research Council committee report (NRC 1997) concluded that;

    • Living in homes classified as being high in the wire-code category is associated with about a 1.5-fold excess of childhood leukemia, a rare disease.

    • MFs measured in the home after diagnosis of disease in a residence have not been found to be associated with an overall excess incidence of childhood leukemia or other cancers.

    • Studies have not identified the factors that explain the association between wire codes and childhood leukemia.

    • Taken together, epidemiologic evidence does not support possible associations of MFs with adult cancers, pregnancy outcome, neurobehavioral disorders, and childhood cancers other than leukemia.

    • MF exposures at 50–60 Hz delivered at field strengths similar to those measured in typical residential exposures (0.01–1.0 µT) do not produce any significant in vitro effects that have been replicated in independent studies.

    • Reproducible changes have been observed in the expression of specific features in the cellular signal-transduction pathways for MF exposures at about 100 µT and higher.

    • There is no convincing evidence that exposure to 60-Hz power-frequency magnetic fields causes cancer in animals.

    • There is no evidence of any adverse effects on reproduction or development in animals, particularly mammals, from exposure to power-frequency 50- or 60-Hz EFs and MFs.

    • There is convincing evidence that low-frequency pulsed MFs greater than 0.5 mT are associated with bone-healing responses in animals.

    A number of additional conclusions and recommendations in the Research Council committee report referred to findings and recommendations about research needs.

    The final summary and evaluations of the NIEHS working-group report (NIEHS 1998a), offer the following statements:

    • The working group concluded that ELF MFs are "possibly carcinogenic" in humans (supported by 19 members; eight members considered the evidence as not allowing a classification as to carcinogenicity, one member considered the evidence as indicating noncarcinogenicity in humans, and one member abstained from voting).

    • Of 26 working-group members voting on the question, 20 concluded that there was limited evidence that residential exposure to ELF MFs is carcinogenic in children on the basis of the results of epidemiologic studies of childhood leukemia; the remaining six voting members concluded that there was inadequate evidence.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
    • Of 25 working-group members voting on the question, 14 concluded that there was limited evidence that occupational exposure to ELF MFs is carcinogenic in humans, primarily on the basis of results of studies of chronic lymphocytic leukemia; the remaining 11 voting members concluded that there was inadequate evidence.

    • Of 25 working-group members voting on the question, 22 concluded that there was inadequate evidence of an association between occupational exposure to ELF MFs and the risk of cancers other than leukemia; two members concluded there was limited evidence, and one that there evidence for lack of an effect.

    • Of 25 working-group members voting on the question, 24 concluded that there was inadequate evidence that residential exposure to ELF MFs is carcinogenic in adults; the other member concluded there is evidence for lack of an effect.

    • All 25 working-group members voting on the question concluded that there was inadequate evidence of an association between exposure to ELF MFs and childhood nervous system tumors or childhood lymphoma.

    • Of 27 working-group members voting on the question, 19 concluded that there was inadequate evidence in experimental animals of the carcinogenicity of exposure to ELF MFs; the remaining eight members concluded that there was evidence of lack of an effect.

    It is worth noting that no working-group member voted for the conclusion that ELF MFs are "carcinogenic" or "probably carcinogenic". It is unfortunate that the summary statements focused so heavily on cancer. The extensive literature reviewed in the report addressed effects other than cancer.

    When the working-group report is considered in more detail, the dramatic contrast apparent between the Research Council committee report (NRC 1997) and the NIEHS report (NIEHS 1998a)—"no effect" versus "possible carcinogen"—is reduced; and when the differences between the two evaluation processes that were used are taken into account, the difference in conclusions is understandable. The current committee concludes, however, that the conclusions of the 1997 Research Council committee report (NRC 1997) more accurately convey the health implications of the underlying research to the public.

    Several national and international organizations are involved in developing exposure guidelines for EFs and MFs, and several such guidelines have been published for power frequencies. The predecessor of the International Commission for Non-ionizing Radiation Protection (ICNIRP) and the International Non-ionizing Radiation Committee (INIRC) of the International Radiation Protection Association (IRPA), published exposure guidelines for power-frequency EFs and MFs in 1990 (ICNIRP 1990; IRPA/INIRC 1990). These guidelines were recently updated by ICNIRP (ICNIRP 1998) and extended to include exposure to power-frequency magnetic fields with frequencies up to 300 GHz. Similar guidelines or standards have been developed by the American Conference of Governmental Industrial Hygienists (ACGIH 1998) and by the Institute of Electrical and Electronic Engineers (IEEE 1997). These guidelines are based on known acute effects of EFs and MFs. Although all those organizations are aware of the epidemiologic literature dealing with reported associations between EMF exposure and different cancer end points, the data from such experiments have not affected the recommended exposure guidelines. The reasons are the lack of quantitative data about

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×

    these associations, the lack of consistency in the reported outcomes, and the lack of adequate characterization of the exposures. It is not possible to determine how much protection can be obtained against undefined risks that might or might not exist at relevant exposures. In the absence of clear, reproducible effects at relevant EMF exposures, the tendency is often to limit exposures specific to the situation or to prescribe that exposures at new installations be held below levels experienced in existing installations.

    Discussion and Recommendations

    The results of the EMF-RAPID program do not support the contention that the use of electricity poses a major unrecognized public-health danger. Basic research on the effects of power-frequency magnetic fields on cells and animals should continue, but a special research funding effort is not required. Investigators should compete for funding through traditional research-funding mechanisms. If future research on this subject is funded through such mechanisms, it should be limited to tests of well-defined mechanistic hypotheses or replications of reported positive effects. If carefully performed, such experiments will have value even if their results are negative. Special efforts should be made to communicate the conclusions of this effort to the general public effectively.

    The following specific recommendations are made by the committee:

    1. The committee recommends that no further special research program focused on possible health effects of power-frequency magnetic fields be funded. Basic research on the effects of power-frequency magnetic fields on cells and animals should continue but investigators should compete for funding through traditional research-funding mechanisms.

    2. If, however, Congress determines that another time-limited, focused research program on the health effects of power-frequency magnetic fields is warranted, the committee recommends that emphasis be placed on replications of studies that have yielded scientifically promising claims of effects and that have been reported in peer-reviewed journals. Such a program would benefit from the use of a contract-funding mechanism with a requirement for complete reports and/or peer-reviewed publications at program's end.

    3. The engineering studies were initiated without the guidance of a clearly established biologic effect. The committee recommends that no further engineering studies be funded unless a biologic effect that can be used to plan the engineering studies has been determined.

    4. Much of the information from the EMF-RAPID biology program has not been published in peer-reviewed journals. NIEHS should collect all future peer-reviewed information resulting from the EMF-RAPID biology projects and publish a summary report of such information periodically on the NIEHS Web site.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
    1. The communication effort initiated by EMF-RAPID is reasonable. The two booklets and the telephone information line are useful, as is the EMF-RAPID Internet site. There are two limitations to the effort. First, it is largely passive, responding to inquiries and providing information, rather than being active. Second, much of the information produced is in a scientific format not readily understandable by the public. The committee recommends that further material produced to disseminate information on power-frequency magnetic fields be written for the general public in a clear fashion. The Web site should be made more user-friendly. The booklet Questions and Answers about EMF should be updated periodically and made available to the public.

    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
    ×
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Suggested Citation:"EPACT Committee Review of Completed Projects." National Research Council. 1999. Research on Power-Frequency Fields Completed Under the Energy Policy Act of 1992. Washington, DC: The National Academies Press. doi: 10.17226/9587.
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    Since the 1970s, concerns about health hazards associated with electric and magnetic fields from power lines and from workplace, school, and household use of electricity have led to many studies and continued controversy about whether adverse health effects occur. In the Energy Policy Act of 1992 (Public Law 102-486), Congress authorized a focused national research program to study the possible health effects of exposure to low-intensity, 60-hertz electric and magnetic fields. In response to this legislation and at the request of the Department of Energy (DOE), the National Research Council established a committee under the Board on Radiation Effects Research (BRER) in the Commission on Life Sciences (CLS) to aid in its review of the power-frequency magnetic field research activities completed under the Electric and Magnetic Fields Research and Public Information Dissemination (EMF-RAPID) program that was authorized by the Energy Policy Act. The Research Council's Committee to Review the Research Activities Completed Under the Energy Policy Act of 1992 (EPACT) was asked to review the EMF-RAPID program implemented by DOE and the National Institute of Environmental Health Sciences (NIEHS), and research strategies suggested by other federal and nonfederal groups.

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