The use of electricity is of great benefit to society in residential and occupational settings. Many of our daily routines would be severely disrupted were it not for electric power to control our indoor climate, store and prepare our food, clean our homes and clothing, and perform other tasks at home and at work. The ever-expanding use of electricity has not, however, come without risks: Most notable is the potential for shocks and burns from contact with energized electrical conductors. Recently, public concern has grown over the possibility that more subtle adverse health effects might exist as a result of exposure to the electric and magnetic fields (EMF) surrounding electric power transmission and distribution lines and the electric devices that have become common tools of the residence and workplace.
Numerous epidemiologic studies show an association between living near power lines and the incidence of some childhood cancers. In addition, several studies suggest that some adult cancers might be associated with occupations in which workers are exposed to elevated levels of power frequency (50-60 Hertz [Hz]) EMF. Most epidemiologic studies focus on the magnetic fields associated with 50 or 60 Hz power systems. The reported associations are generally weak and the suggested causality is highly uncertain. Reports of these studies in the popular news media, however, have excited a great deal of public concern, which in turn has been a driving force in setting research agendas for the study of extremely low-frequency (ELF) EMF by government agencies and private organizations.
Research on the biologic effects of exposure to ELF-EMF has been under way for more than two decades, and an extensive literature has accumulated. However, the scientific literature has not clearly demonstrated mechanisms by which power frequency EMF might induce changes that would lead to detrimental health effects. Research findings in this area are characterized by large uncertainties and, until recently, relatively few efforts have been made to replicate results in independent laboratories. Furthermore, in cases where reproduction of experimental results has been attempted, the results have not been reproduced consistently. These uncertainties have led to a continuing controversy within the scientific community regarding the potential for 60 Hz EMF to harm human health and to a public outcry for resolving the uncertainties.
Because of the increasing public concerns, several workshops were held between 1990 and 1992 to review the state of knowledge and to discuss strategies for future research work to illuminate the issues. These workshops included participants from the Department of Energy (DOE), the National Institute of Environmental Health Sciences (NIEHS), the Environmental Protection Agency, the Electric Power Research Institute, public utilities, state governments, scientists, and others. The workshops established a basic framework for an enhanced national program in EMF research that was ultimately authorized by Congress in the Energy Policy Act of 1992 (Public Law 102-486).
Under Item 303, Section 2118, the act outlined a 5-year, $65 million program, that would involve a partnership of government and industry in determining whether environmental exposure to power frequency EMF poses a public health risk. The resulting Electric and Magnetic Fields Research and Public Information Dissemination (EMF-RAPID) program, has three primary components: The first is to determine whether exposure to EMF produced by the generation, transmission, and use of electric energy adversely affects human health. Second is to carry out research, development, and demonstration of technologies that would mitigate any adverse human health effects. Finally the program would provide for dissemination of information related to the possible human health effects of EMF exposure. The legislation established a National EMF Interagency Committee (IAC) and a National EMF Advisory Committee (NEMFAC) to guide the effort. In addition, the secretary of energy was directed to enter into an agreement with the National Academy of Sciences (NAS) to evaluate the research activities completed under the program and to report its finding to DOE, IAC, and NEMFAC.
In response to the directions of the Energy Policy Act of 1992 and a request from DOE, the National Research Council (NRC), the principal operating agency of the Academy, through its Board on Radiation Effects Research, established a committee of scientists and engineers to aid in its review of the activities conducted under the EMF-RAPID program. The NRC committee was also asked to review the research agenda and strategies adopted by DOE and NIEHS, as well as those suggested by other federal and nonfederal groups. More specifically, the NRC committee was asked to: review and evaluate the scientific and technical content of projects completed under the EMF-RAPID program; to review continuing research projects for scientific content and suitability to meet the goals of the EMF-RAPID research plan; to recommend modifications to the EMF-RAPID program, as appropriate, based on information the committee acquires about new research findings not available when the national research agenda was developed; and to assess the scientific and technical content, and recommend changes as necessary, for activities initiated under the EMF-RAPID program to promote the transfer of information derived from research projects.
The results of the NRC committee review and evaluations are to be reported to DOE and to IAC and NEMFAC annually. A final report, to be submitted at the conclusion of the EMF-RAPID program, will assess the research activities conducted under the act. This report is the first annual report concluded by the NRC committee under the EMF-RAPID program.
A great deal of care has gone into the development of the research
strategy for the EMF-RAPID program, and no glaring omissions in the program can
be identified. Previous research conducted on the biologic effects of exposure
to EMF and published in the scientific literature has been criticized as being
abundant with inconsistencies, containing large uncertainties, and not having
been confirmed by other investigators. Another criticism is that experiments
have predominantly been conducted with exposures that are large relative to
those encountered in the residential environment under normal conditions.
Therefore, the research strategy for the EMF-RAPID program has as its major
objectives the identification and quantification of appropriate environmental
exposure parameters, the reproduction of several crucial biologic experiments,
a commitment to reduce experimental uncertainty through the use of a team
approach to experiment design, and the requirement of good laboratory practices
in the research. An important component of the research strategy has been an
effort to bring new researchers with excellent credentials for biologic
research into this field of study. The research strategies seem consistent
with the stated goals of the program.
RESEARCH STRATEGY AND AGENDA
The EMF-RAPID program must balance the desired depth and breadth within
its limitations of time and budget. This has brought about a focus on research
areas that are most critical to developing a data base that could be used in
risk assessment studies. A major difficulty in assessing the ability of the
research agenda to meet its risk assessment goal is the lack of a specific,
defined methodology for undertaking risk assessment for any agent that
interacts similarly to EMF exposure in contributing to adverse health effects.
Without such a methodology, it is difficult to set a research agenda that will
maximize the probability of success. Under the circumstances, the research
strategy has been designed to focus initially on replication of experiments
deemed important to identifying possible risk factors.
Among the major difficulties affecting the potential of the EMF-RAPID
program to meet its goals are the methods of research administration and the
limitations on time and budget. First, it is difficult to obtain definitive
results on demand from a program of investigator-initiated basic research.
Second, a significant amount of program time was devoted to setting up the
machinery for initiating the coordinated program; this delayed the start of the
actual research. The first research grants were awarded nearly two years after
the program's congressional authorization. At a minimum, this suggests that
Congress should consider extending the program for 2 years, to 1999, to allow
completion of the planned research.
The administration of the EMF-RAPID biologic research program by means of
the National Institutes of Health's (NIH) investigator-driven, grant-funded
method of research funding also is a major difficulty. Although a highly
refined method of funding investigator-initiated basic scientific research, it
was not developed with the intent of organizing and funding a program of
research with a specific aim. This also has contributed to a delay in meeting
the program's 5-year deadline.
Some areas of hypothetical importance to explaining a possible link
between exposure to power frequency EMF and as yet unidentified adverse health
effects are not included in the program; however, the program's emphasis on the
health end point of cancer and on exposures to standard sinusoidal 60 Hz EMF is
the only reasonable research agenda in view of cost limitations and the
unlimited number of co-promotor and other feasible health end point effects,
and the only way to ever bring the program to a conclusion that will
satisfy most reasonable concerns.
STUDIES INITIATED
Several studies have begun under the EMF-RAPID program in the areas
of engineering, managed by DOE, and in vitro and in vivo biology, managed by
NIEHS. The engineering studies focus on source characterization and exposure
assessment for the power-frequency EMF to which people are commonly exposed.
Electric and magnetic field management portions of the program are being
postponed until later, when a better understanding of the environmental
characteristics of EMF and their biologic significance might be available.
The in vitro studies focus on confirmation of earlier work on the effects
of 60 Hz exposures on expression of the early-response genes, such as myc, fos
and jun, and on the properties of membrane transport in mammalian cell systems.
In vivo studies focus on the effects of EMF exposure as a promoter or
copromoter of tumors and on the alteration of melatonin levels in animals
exposed to EMF and on the likely consequences of observed changes in melatonin
concentrations. It must be recognized that when attempting to replicate
previous experiments, one must follow the original protocol with
obsessive precision because, there being no accepted theory of why one should
see any effect at all, one has no idea as to which steps are truly
essential and which can be modified or bypassed.
Engineering Studies
Six studies were scheduled to begin in fiscal year 1994 under the exposure
assessment and source characterization portion of the program. Four of these
are for the development of guidelines for measurement procedures and for
establishment of a data base to make data that is collected readily available.
The other two studies are for the initiation of a 5-year project of human
exposure assessment and environmental surveys. It would have been preferable
to initiate the latter two projects after the completion of the first four, but
the time allocated by the program did not permit this delay. Exposure
assessment and source characterization studies are scheduled in four more
project areas in fiscal year 1995, but none was in progress at the time this
report was prepared (July 1995).
The exposure assessment and source characterization is a large
undertaking burdened with significant inefficiencies as a consequence of the
schedule. Because it is not known which aspects of ELF-EMF exposure, if any,
adversely affect human health, a prudent measurement program requires
comprehensive measurements covering a wide range of the EMF attributes. To do
otherwise risks failing to capture the relevant information. Even then, the
EMF measurements taken might fail to capture the appropriate attribute or
combination of attributes, and therefore it is possible that some of the
accumulated data will be irrelevant. Consequently, it is difficult to
understand the urgency of extensive statistical sampling projects to fill data
bases that will be needed only if adverse health effects are confirmed.
Two objectives are identified for the electric and/or magnetic field
management portion of the EMF-RAPID engineering research activity. First,
there should be an evaluation of the costs, benefits, and effectiveness of
options for managing EMF exposure, and second, if needed, new techniques should
be developed for management on the appropriate EMF components. Both are
appropriate and attainable engineering efforts, once the relevant
characteristics of exposures are understood.
The planned engineering research activity for quality assurance has just
one objective and one project (funding for quality control efforts in a program
the size of the EMF-RAPID program is clearly appropriate). The project
identified is an expansion of a continuing effort currently funded by DOE
outside the EMF-RAPID program.
In Vitro Studies
Fourteen projects were initially funded under the in vitro portion of the
EMF-RAPID program. The primary focus of these projects is on the reproduction
of seminal work in calcium ion transport, membrane transport, enhanced
expression of early response genes, free-radical effects, and cellular
promotion and copromotion by exposure to EMF. Confirmation of earlier results,
or the lack on confirmation, should lead to firm conclusions about whether
60-Hz magnetic fields are biologically active in mammalian cells. If the
results are positive they should be useful in establishing testable hypotheses
for further studies.
In Vivo Studies
About one-third of the funds available in the initial grants of the
EMF-RAPID program for the study of biologic response to 60 Hz magnetic field
exposure was applied to the study of possible in vivo effects. Six studies
begun in 1994 were split between exploring the role of 60 Hz magnetic fields on
the modulation of melatonin and on the role of 60 Hz magnetic fields as a
cocarcinogen in three tumor systems. This effort is focused on an extremely
limited scope of exposure characteristics and biologic responses, and it must
be recognized that if a component of EMF other than the putative 60 Hz
sinusoidal character is biologically active or if the response is manifest in
terms other than the particular end point under investigation, this set of
studies might not detect possible effects of EMF exposure, and negative
findings could be inconclusive. Furthermore, the effort is so small that it
does not provide for replication of results, as does the in vitro portion of
the research program.
PROJECTS COMPLETED
Because the program has only recently begun, just one project has
been completed and provided to the NRC committee for review. That project,
prepared under the public information dissemination portion of the EMF-RAPID
program, was the development of Questions and Answers About Electric and
Magnetic Fields Associated with the Use of Electric Power (DOE, NIEHS,
1995). The NRC review committee believes this is an excellent document for the
audience intended. For the most part, the booklet provides factual, unbiased
information in a language that is useful to a large segment of the population.
However, in the process of simplifying concepts, several minor technical errors
were introduced. It must be noted that these errors are not significant,
should not mislead anyone, and are considered to be offset by the availability
of information at a level that can be understood by the lay public. This
effort to present information in a clear and concise manner is considered
extremely important.
In the same manner that the program planning for engineering studies
suffers from not knowing the biologically relevant field parameters, the
planning of biologic studies suffers from the lack of information about the
risk assessment technology to be used. The EMF-RAPID program also is limited
in that it includes little effort to seek information on the effects of EMF
exposures other than to sinusoidal 60 Hz magnetic fields. Moreover, the
emphasis is almost exclusively on cancer as the end point. Effects from the
combination of alternating current fields from power lines or electrical
devices with the static components of the geomagnetic field, or from transients
that involve relatively large and rapid changes in the electric or magnetic
field, could be important in initiating biologic response. Consideration also
should be given to such biologic end points as neurobehavior and reproduction
and development.
FIELD MITIGATION
A primary goal identified by the EMF-RAPID program is to examine
techniques to mitigate risks from exposure to EMF. Within the context of the
limited schedule, and given the lack of information about biologic effects,
pursuing this goal seems premature. It is recommended that this task be
delayed until the risk factors have been better defined.
PROGRAM EXTENSION
Finally, the delays encountered in starting the program and the time
constraints inherent in the grants process strongly argue for an extension of
the sunset clause of the Energy Policy Act of 1992. Two more years are needed
to ensure timely completion of the research projects still to begin under the
EMF-RAPID program. We urge Congress to consider allowing an extension.
PROGRAM COMPLETION
With any program of this complexity, there comes a time when it is
necessary to determine that an adequate answer is at hand and that research
should be curtailed. The EMF-RAPID program should include a formally structured
administrative mechanism to conclude whether the data taken in toto support the
concept that a significant risk from ELF-EMF does, or does not, exist. Most
programs established to evaluate potential risks of exposure to environmental
agents are difficult to terminate, given the interests of the
individuals involved. The competing interests should be recognized and a
method to integrate multiple pressures should be developed. This could
be accomplished within the formalities of the risk assessment process, or it
could be a separate process of review of the risk assessment.
INFORMATION DISSEMINATION
The information booklet, Questions and Answers About Electric and
Magnetic Fields Associated with the Use of Electric Power, is a
commendable effort of exceptional value for providing information to the lay
public. However, our review revealed several minor errors. We recognize that
the booklet was subjected to numerous reviews and that the minor errors we
detected should not mislead the lay reader. However, it is recommended that
experts in engineering, physics, and biology should review subsequent booklets.
Although commendable, the booklet provided only a brief discussion of the
results of in vitro and in vivo investigations of the effects of exposure to
ELF-EMF. We recommend that another booklet expand the discussion to include
laboratory studies. In addition to summarizing completed research, the booklet
should discuss uncertainties, the origin of uncertainties, and their effects on
the risk assessment process. This information should be prepared for the lay
audience, but it should include a relatively complete listing of appropriate
scientific literature for the more interested reader.
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