HomeMy WebLinkAboutPACKET Light and Power 1987-12-034 7- I LIGHT & POWER COMMITTEE 730 December 3, 1987 AGENDA 1. Authorization to bid vehicle 2. Authorization to purchase personal computer Reports 1. R.F.P.'s for service building design 2. Hidden Valley 3. Electromagnetic fields and childhood cancer 4. Disconnects for non-payment 5. Hand held meter reading devices
r' -'1 I ... THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL The School of Public Health The University Of North Carolina at Chapel Hill Department of Epidemiology Rosenau Hall 201 H (919) 966-3731 Chapel Hill. N.C. 27514 To: Persons concerned about reports of electromagnetic fields and childhood cancer From: David A. Savitz, Ph.D. Department of Epidemiology School of Public Health University of North Carolina Chapel Hill, NC 27514 The recent publicity concerning our study of childhood cancer and electromagnetic field exposure has resulted in a number of inquires regarding my judgment of the appropriate response by individuals. This memo reflects the best information which I can offer at the present time. As indicated in the press coverage, our study suggests a link between prolonged magnetic field exposure from electric power lines near residences and risk of childhood cancer. It -should be kept in mind, however, that we have not proven that - -- magnetic fields cause cancer. Subsequent research will indicate whether we are on the right track or whether our results are in error. Thus, there is a suggestion of a possible hazard which has yet to be resolved. Given these circumstances, it seems that interest or concern may be justified, but our study is not sufficiently convincing to warrant drastic action by homeowners. Ultimately, the response to this type of information (possible, but unproven hazard) requires an individual judgment about risk, much as the decision regarding suspected dietary hazards, flying in airplanes, or drinking alcohol or coffee reflects differing individual judgments. If it is learned, eventually, that magnetic fields do increase risk of childhood cancer, this would be of great concern as a public health issue. Nonetheless, childhood cancer is fortunately a very rare event, with about 1 in 10,000 children developing cancer per year. If the risk really were 1.5- to 2-fold greater among persons with elevated magnetic field levels, the risk would be 1.5 or 2 cancers in 10,000 children per year. Again, this would be very important, but minor relative to childhood injuries or risks from known cancer hazards to adults such as cigarette smoking or asbestos exposure.
r. 1 . . 2 1 The question has also been raised regarding what an individual can do to reduce magnetic field exposures. Unfortunately, the magnetic fields from electric power lines are not easily reduced. Magnetic fields readily penetrate building materials, so that the exposure level is determined by the current flow in the nearby power lines and the proximitY of the residence to those lines. The further away one is, the lower the exposure. The only readily changed personal exposure to magnetic fields would be through avoidance of electric blankets or heated waterbeds. The question of what distance from what types of power lines is "safe" is really not answerable: We don't yet know with certainty-that any distance is unsafe. If there are health effects from magnetic fields, there is no firm basis for estimating at what level of exposure risk is increased. In our data from the Denver area, high exposure was defined based on levels above 2-3 milligauss, a unit of magnetic field strength. These exposure levels are related to the type of power line, current flow, and distance but there is no simple way to determine what the exposure will be from the wires near a given home. I recognize that this information fails to answer the question of whether there is a health hazard from power lines and what an appropriate response should be. At the present time, the first question is unresolved so that the individual's response can only be based on his or her best judgment with the existing uncertainty.
State of New York Department of Health New York State Power Lines Project Questions and Answers The New York State Department of Health has received many questions since the July 8, 1987 release of the New York State Power Lines Project report. The following are the Department's answers to many of those questions, which have come from parents and homeowners. lawyers and engineers, real estate people and utility companies. 1. Why was the New York State Power Lines Project started? To evaluate the possible health effects of electric and magnetic fields produced by electric power transmission lines. The study was part of an agreement involving state approval of the installation of a major power line across upstate New York. Utility companies in the state funded the $5 million research project, but had no role in designing or evaluating the actual research. An independent panel of nine scientists selected the areas to studv and the research projects to be funded. Of the more than 150 proposals submitted from scientists throughout the United States and Canada. 16 were selected for funding. 2. What are electric and magnetic fields? These are fields created by the combination of voltage on the power line conductors and electrical current through the conductors. These fields are produced not just by power lines, but wherever there is electricitY. Sources include everyday home appliances such as clothes dryers, electric blankets. hair dryers and toasters. 3. Are power line fields regulated in New York State? How? Yes, there is a limit on maximum electric field strength on the right-of-way of 10 kilo volts per meter and at the edge of the right-of-way of 1.6 volts per meter. The Public Service Commission sets and enforces the limits bv requiring that a utility apply for a transmission line construction certificate to show that these limits are not exceeded.
4. What are the alternatives to overhead high voltage transmission lines? Possible alternatives are underground transmission lines or on-site power generation. 5. What is known about the relationship. if any. between electric and magnetic field exposure and health effects? Not very much. and that is why the study project was launched in the first place. Relatively little research has been done in this area. The Power Lines Project report shows evidence of some biological effects related to laboratory exposure to magnetic fields. But a direct link to health effects has not been established. 6. Can electric and magnetic fields cause cancer? The Power Lines Project funded two related epidemiological studies - one involving cancer in adults and the other cancer in children. The adult study, conducted in Seattle. showed no relationship between cancer cases and low-level magnetic fields from the power distribution lines in the neighborhood. The childhood study. in Denver, did show a statistical relationship between cancer cases and a proximity to local power lines. 7. Does the childhood cancer study prove that electric and magnetic fields cause cancer? No. The study shows a correlation (an association) between proximity to the power lines and higher childhood cancer rates. but it does not demonstrate a cause and effect relationship. Further, no one has determined what bioloqic process or mechanism electric and magnetic fields might use to cause or encourage the growth of cancer. Much more research is needed on this question, which relates to long-term exposure.
8. But what if the correlation does prove true in further studies? The review panel stated that "at this time, no risk assessments can be made.u The panel nevertheless estimated that if the power lines did cause the cancer cases in Denver. and the same power line patterns exist elsewhere in the country, then magnetic fields could be causing 10% to 15% of all childhood cancers in the United States. This *stimate is based purely on statistical extrapolation. The Denver study found that close proximity to power lines seemed to result in a near doubling of cancer -risk in children, i.e.. from one case in 10,000 to two cases in 10.000. 9. Did the Denver study include all types of chfldhood cancer? Yes. The study examined all cancer cases in the Denver area in children aged 0-14, between 1978 and 1983. The most common cases were leukemias or brain tumors. 10. What did the other Power Lines Project studies show? No effects were found in the laboratory animal studies on reproduction. growth or development. Several studies showed no evidence of genetic or chromosomal damage that might lead to inherited effects or cause cancer. Most measurements of behavior and brain function did not demonstrate any biological change. but some did show small effects. Some appear to result from body rhythm changes. and might interfere with normal sleep patterns. There were also changes in pain response and the ability of rat pups to learn. The connection between these laboratorY results and human health effects is not known. 11. Can magnetic fields in and around homes be measured? Yes, though the instruments are expensive and complicated. Most Utility companies do not provide that service. nor does local or state government.
. 12. Should I have the fields in and around mv home measured? Is there a safe level? This is a question each individual has to answer, but the Health Department is not recommending such a measurement. There is no level agreed upon by scientists or set by any government authority as being unsafe. The scientists who supervised the studies and authored the Power Lines Project report debated whether to recommend that New York establish a maximum limit for magnetic fields. They decided not to because of a lack of solid scientific evidence demonstrating a need for such standards. 13. Power lines run over my home. Or, I live near a substation. Should I move? There is no scientific recommendation or government regulation to help answer the question. It aopears that the risks. if any. are low, and therefore the Department of Health recommends no action until further research results are available. 14. Should I build or purchase a home near power lines? The answer is the same as to the previous question. 15. Since I live near power lines. should I have my children examined b¥ a physician? The Health Department does not recommend any special medical examinations because of this studY. Routine annual check-ups are the Department's standard recommendation. 16. What about research on occupational exposure to electric and magnetic fields? The Power Lines scientific panel reviewed the existing research, which it found inconclusive. However, a number of studiEs have shown a pattern suggesting that occuoations with a close exposure to electric and/or magnetic fields have an increases risk for leukemia. These occupations include telegraph and teleghone operators, teleghone and power linemen, electrical anc electronic engineers and electronic assemblers. The panel urged further research.
. 17. What else did the panel recommend? The panel recommended that research be conducted on how to reduce the magnetic field produced by power lines. Though no conclusive health effects were documented, the panel felt that there now exists enough evidence to cause concern. and that it would be prudent to search for ways to reduce magnetic fields. The federal government and the utility industry may want to sponsor such research. The panel also urged that national studies be undertaken to test the childhood cancer findings in this project report. The Health Department has written the National.Cancer Institute, the Federal Department of Health and Human Services, the National Academy of Sciences and the National Science Foundation to suggest continued investigations. For more information, or a copy of the full Power Lines Project report, write to: Ms. Patricia M. Lanphear NYS Department of Health Room 1455, Corning Tower Building Empire State Plaza Albany, NY 12237 (518) 474-7354 August, 1987