SUMMARY OF EPACT COMMITTEE INTERIM REPORT
The interim report of the EPACT Committee, EMF Research Activities Completed Under the Energy Policy Act of 1992 (NRC 1995), briefly discussed the status of research related to the biologic effects of MF exposure. A review of the research strategy adopted by the EMF-RAPID program (including program strengths and limitations) discussed work initiated under the EMF-RAPID program, reviewed the one project that had been completed at the time the report was written, and presented the conclusions and recommendations. A brief summary of each of these components of the interim report follows.
Status of Research Related to Biologic Effects of Power-frequency Magnetic Field Exposure
The biologic-effects portion of the interim report began with a description of the risk-assessment process, which appeared to be a central focus of the EMF-RAPID program. Although expressing some doubts that the three goals of the risk-assessment process (characterization of toxicity, definition of hazard, and conduct of risk assessment) were achievable in the time frame of the EMF-RAPID program, the committee noted that in vitro and in vivo studies have an intrinsic value in that "the determination of biologic sensitivity to EMF exposure should be considered as an important component of toxicology, independent of the direct application to risk assessment".
The biology portion of the research effort was just getting started at the time of the interim report; research results were for the most part not available, so they were not evaluated by the committee. The in vitro and in vivo components of the program were described.
In vitro studies
The following goals of the in vitro studies were identified in the interim report:
Replication of studies that had previously indicated a cellular response to power-frequency magnetic field exposure.
Identification of one or more cell systems that produce a robust response. It was emphasized that such systems are needed "to characterize those components of power-frequency magnetic field that are essential to elicit response, as well as to determine temporal patterns of the response".
Identification and characterization of possible mechanisms that would lead to the establishment of clear hypotheses for biologic effects of power-frequency magnetic fields.
In vivo studies
The committee observed that in vivo studies complement and bridge information obtained from in vitro and epidemiologic studies. It noted that the following points should be considered if in vivo data are to be used in a risk-assessment context:
The experimental animal must be an appropriate surrogate for human response to the tested agent.
The ability to detect small toxic effects can be severely limited by the number of animals that can be assayed.
Chronic toxic effects must be interpreted in animal studies through a knowledge of the dose-response relationships for the toxic effects of concern.
Review of Research Strategy Adopted by EMF-RAPID Program
The interim report noted that the research strategy of the EMF-RAPID program attempts to balance breadth and depth within a limited budget and schedule. The committee found no glaring omissions in the program but recommended that it "include mechanisms for seeking rapid confirmation of important observations and for the rapid implementation of studies that seek to test new hypotheses that appear especially relevant".
Strengths and limitations of the program were noted. Of the three specific goals stated in the Research Agenda and Communication Plan, EMF-RAPID Program (DOE 1994a), the committee expressed doubts that the first goal, determination of the health effects of MF exposure, could be definitively reached within the limitations of the 5-yr program. It noted that the second goal, development of techniques to mitigate any adverse health risks, seemed premature. The third goal, dissemination of scientifically valid information to the public, was considered appropriate and a clear strength of the program. Program weaknesses cited by the committee included the absence of a clearly defined methodology to be used in risk determination. Another shortcoming noted by the committee was the decision to conduct all biology and health-related research through the NIH grant process. The committee strongly recommended that a special study section be formed within the EMF-RAPID program to evaluate new proposals and competing renewals of program projects, particularly with a view to bringing the program to closure in some reasonable period. It was also recommended that the program office consider selected use of cooperative agreements to allow more-focused studies to be performed when needed.
The interim report commented on the EMF-RAPID program strategy and tactics, citing the emphasis on replication studies and the fact that the broad approach for cultured-cell systems was combined with a more specific focus on copromotion-cocarcinogenesis and melatonin effects in the animal studies. The committee felt that the strategy represented a solid compromise based on intriguing data and reasonable hypotheses but that it was unlikely over the program's lifetime to produce a database sufficient to support a formal risk analysis.
Description of Work Initiated Under EMF-RAPID Program
The interim report noted 16 current and 10 expected engineering projects, 10 communication projects, 14 in vitro biology projects, and seven in vivo biology projects. Some proposed engineering and communications projects were eventually canceled because of budget cuts. The number of EMF-RAPID-funded NIEHS in vivo and in vitro projects, however, increased to a total of 61 projects.
Review of Completed Project
The only EMF-RAPID project that had been completed at the time of the interim report was the booklet Questions and Answers About Electric and Magnetic Fields Associated with the Use of Electric Power (DOE 1995). The booklet was judged by the committee to present objective responses to a variety of questions that might be asked by a concerned public. The answers were for the most part accurate and presented in nontechnical language. It was noted that the booklet contained an excellent discussion of the epidemiologic data that had caused public concern. Although the booklet noted the importance of statistical uncertainty, the committee concluded that the tables should have included confidence limits. The committee also noted that the booklet should have made clear that the associations being considered were, for the most part, with surrogate measures of MF exposure, such as job titles, and that associations with measured fields were not made. Several technical errors were pointed out, but it was thought that they would not substantially mislead the public. The committee concluded that more booklets of this sort should be published and suggested that it would be useful to prepare a more comprehensive guide that would include biologic effects observed in the laboratory from exposure to power-frequency magnetic fields.
Conclusions of the Interim Report
In general, the interim report concluded that the EMF-RAPID program had several commendable components including identification and quantification of appropriate environmental exposure characteristics, reproducibility of crucial biologic experiments, a commitment to reduce experimental uncertainty through a team approach to experimental design, and emphasis on good laboratory practices.
Regarding the research strategy and agenda, the committee noted that it would be difficult to obtain definitive results on demand from a program of investigator-initiated basic research. The situation was complicated by the fact that the program got a late start: the first research grants were funded a year after congressional authorization. Projects were then funded at various times throughout the program. The lack of a specific, defined method for undertaking risk assessment also was cited as posing a difficulty in judging the ability of the program to meet its risk-assessment goal.
Recommendations of the Interim Report
The interim committee report recommended that the EMF-RAPID program develop the process by which data would be incorporated into a formal risk analysis and make that process known to the program managers as a guide to the research-planning effort. [The present EPACT Committee notes that a working group was convened to produce an informal assessment of hazard to humans from MF exposure. On the basis of IARC guidelines, a vote was taken by the NIEHS working group and ELF-MF were placed in the classification of ''possibly carcinogenic" (NIEHS 1998a). A formal risk analysis had not been done at the time of this review].
The interim report recommended that a special NIH study section be used to evaluate new proposals and competing renewals. This study section should include people with a broad and specific knowledge of MF research. In addition, a funding mechanism should be included to allow for the rapid implementation of studies that seek either to replicate important findings or to test new hypotheses derived from continuing work. The selected use of cooperative agreements or supplementary applications was recommended to allow a more timely performance of highly focused studies.
The interim report noted that knowledge of mechanisms of MF effects was lacking and that such knowledge would be needed to provide efficient program direction. In general, a focused characterization of environmental exposure as it might be related to biologic effects was urged. No specific recommendations were made. [A 1,000 person evaluation of environmental exposure was completed within the engineering program at a later date].
A primary goal identified by the EMF-RAPID program was to examine techniques to mitigate risks posed by exposure to power-frequency magnetic fields. The interim report recommended that task be delayed until the risk factors had been defined better. [After the interim report, one study on risk mitigation was completed (IIT 1997)].
The interim report urged Congress to consider a 2-yr extension of the EMF-RAPID program. [After receiving input from many sources, Congress granted a 1-yr extension of the EMF-RAPID program to December 31, 1998].
The interim report recommended that the EMF-RAPID program include a formal administrative mechanism to determine whether the data taken as a whole support the concept that a significant risk is or is not posed by ELF MFs. The intent of the recommendation was to provide a mechanism to determine when an adequate answer was at hand and to suggest that further research in this field should be curtailed. [The EMF-RAPID program later funded an NIEHS working group, which, using IARC classifications, concluded that power-frequency magnetic fields are a possible human carcinogen].
Regarding information booklets, the interim report recommended that efforts after publication of Questions and Answers (DOE 1995) be reviewed by experts in engineering, physics, and biology. It also recommended that another booklet be issued for the lay public, expanding the discussion to include laboratory studies and providing a "relatively complete listing of appropriate scientific literature" for "the more interested reader".
A second booklet, Questions and Answers about EMF in the Workplace , produced and distributed by the EMF-RAPID program after the interim report, includes laboratory studies and provides a "relatively complete listing of appropriate scientific literature". The authors note that the booklet was reviewed by experts in federal and state agencies, academic institutions, national laboratories, citizens groups, labor organizations, and industry.