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Comments and Mail From Our Readers
August to December, 1999
Last modified on:
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Copyright © 1994-2008, Information Ventures, Inc.
December 30, 1999
Gerry, USA
My cubicle sits on along a wall that has a 480 Volt line coming in on the other side of it. I cannot place my monitor along this wall because the interference affects it. I have now been sitting with my back to this wall for a year now and I am 3 feet away from it. Does this pose a health risk to me now or possibly later in life? Thanks you for your time and consideration, Gerry
Reply from Dr. Robert Goldberg: Computer monitors can serve as crude indicators of high magnetic field levels because they show image distortion (usually a wavy screeen image) at magnetic field intensities of 10-20 milligauss (mG), depending on the design and size of the monitor. Electric fields from adjacent lines generally don't affect monitors because they are effectively shielded. A magnetic field from an electric line source tends to drop off rapidly as you move away from it, so the solution you have evidently adopted is the most common one -- move the monitor away from the field source. You should look closely at the monitor image to be sure you really have eliminated the interference distortion because even a small jitter can be very tiring to look at and a proven ergonomic stress.
The health issue you raise is harder to address. For the most part, studies have linked long-term adverse health effects with exposures to larger transmission and distribution lines, or to work in industrial settings where exposures are higher and more complex. While the average field levels you are likely to be exposed to are within the range of exposures measured in studies involving residential powerline effects, it is not clear if average magnetic field levels (expressed in mG) relate directly to health effects or if there is some other aspect of the exposure unique to larger powerlines that is more important. There are some indications of adverse effects from appliances and household wiring in the literature, but evidence from those studies, based mainly on self-reported use, are much more uncertain, especially regarding the extent of exposure. As you probably know if you have read much on our web site, even the possible adverse effects of powerlines are uncertain and controversial. For example, the feature article in the upcoming issue of the EMF Health Report discusses the UK childhood cancer study and a study from Bristol about increased exposure to radioactive and hydrocarbon aerosols around power lines released at the same time -- these studies investigating different aspects of the EMF issue come down on opposite sides with regard
to health effects. Since there are so many unknowns, we usually suggest that people evalute the information for themselves and, based on their level of comfort with the uncertainties involved, make informed choices about what exposures they are willing to accept. From what you indicate, I would think you are exposed to relatively high average magnetic field levels at your work and that alone may be a good reason to investigate the health issues further. Regards, Bob
Reply from Gerry: Thank you for your response. There is going to be an attempt to shield the
wall, I just hope that there have been no effects to my health in the past year. Have a happy and safe New Year. Gerry
October 30, 1999
David, USA
Dear Sir/Madam: My wife and baby and I are considering buying a brand new house, but are worried because the transformer that supplies the entire neighborhood with electric power has been placed only 6 ft from our living room, 12 ft from our bedroom, and 20 ft from our baby's bedroom. We are trying to find any applicable laws in Washington state which might disallow such placement of the transformer, or at least some indication of whether or not this is hazardous to our health - can you point us in the right direction, please? If you know of any resources we can tap, or if you can offer any advice, we would be very grateful indeed. Thanks very much, David
Reply from Dr. Robert Goldberg: It is very difficult to predict an exact magnetic field level that would come from a transformer of the type you describe. Field levels should decrease quite rapidly with distance from the transformer, but it seems likely that there would be elevated levels in your intended home, at least at the 6-foot distance. Magnetic field levels depend on the current flowing through a line or transformer. One approach would be to get some magnetic field measurements made, keeping in mind if the development is not fully occupied that you may have to estimate levels under maximum use conditions. Based on a survey of US homes, the average home living area gets an exposure of about 1 milligauss from outside power and distribution lines. You can assess the magnitude of the measured or estimated fields from the transformer in this context and decide if the transformer adds more of an increase than you are comfortable with. The health risks from a transformer exposure are very uncertain and most utilities are not willing to do any expensive revisions of the power distribution system to avoid exposures, except at the homeowner's expense. As far as I know, there are no legal requirements for safety provisions, other than reasonable measures to prevent electrocution, that must be taken around a transformer. Because the health risks of low-level exposures are so uncertain, none of the prevailing exposure standards take them into account in setting limits. There are no clear guidelines of safe and unsafe exposure levels because the scientific information is so limited, and at present the best you can do is to inform yourself about the possible risks of EMF exposure and decide for yourself what exposure level you are willing to live with. Our EMF-Link website and publications, particularly the EMF Health Report, try to provide objective scientific information to allow people to understand the nature of the uncertain risks with EMF. Regards, Bob
Reply from David: Dear Bob, Thanks so much for your response. Buying a house is a big decision,
especially when coupled with the idea of having a transformer 12 feet from my face when I go to sleep every night. We also have to be concerned about our baby playing in that yard. I appreciate your help and any additional advice you may be able to offer.
October 29, 1999
USA
I am writing to you in hope of obtaining some information or insight that may be of help to me. Our neighborhood has a total of 6 breast cancers all within 5 years; 8 houses total on one side. All are on the same side of the street and in back are fields with tension wires. I have had several meetings with city, county and KDHE but everyone refuses to take any action on testing environmentally, saying that there is no known chemical founded that causes breast cancer for them to test. Any insight as to where I might go next? Your help would be very much appreciated since I do not want to give up on this since they are in the process of building a school and am also concerned about students in the future. Susan
Reply from Dr. Robert Goldberg: The reason for cancer clusters is often very hard to track down. Since some groupings of disease will occur by chance, the first step is usually to evaluate how unusual the grouping really is by taking a statistical look at the overall rates. Public health officials usually do this and some (for example, state officials in New Jersey) have a lot of experience doing these investigations. While a causal relationship may seem evident from the sort of clustering you describe, often there are enough differences in the timing, specific types of cancer, and history of the people involved that it is not so clear on evaluation. Activist Paul Brodeur made a strong case for cancer clusters related to EMF at the Slater Elementary School in California and on Meadow Street in Guilford, CT, but scientific evaluations of these locations were not able to pin down a cause. There was a recent article in the New Yorker magazine about the difficulty of investigating cancer clusters ("THE CANCER-CLUSTER MYTH. by A. Gawande, New Yorker 74(45):34-37, 1999). Regards, Bob
October 28, 1999
Alex, USA
I have followed EMF research for years with a grave concern for the health of my daughter who lives in a city apartment building on the ground floor where I measured a field at 60 hz of as high as 170 milligauss sitting in her bathtub. Standing in the middle of the living room was 26 milligauss. I had these results confirmed by an electrician experienced in measuring these fields. The hall/bathroom field comes from feeder cables in the wall going up to 7 floors of apartments. I am pleased that interest in this topic continues but I am not reassured by the negative findings as long as they continue to study levels in the range of < 10 milligauss. I believe that city apartment dwellers may be exposed at an order of magnitude higher than what is being studied. I have not yet been able to attract the attention of anyone in the field (so to speak) with this information. I was told by the electrician that the size of this field is due to the way the phases are wired in the wall. If you know someone who could make use of this information, please pass this along. Alex, New York City
Reply from Dr. Robert Goldberg: Dear Alex, I know several people who made measurements in New York City and they tell me about similar high field levels in apartments and office situations. Since magnetic field intensity depends on the amount of current flowing through a wire, it seems reasonable that such high fields would occur where there is a high occupant density and, since space is so expensive, distances between residences and unused space is minimal. For example, professional office space on the lower floors of many New York buildings tends to have high load feeders passing through it. Because of rent control and other economic reasons, some people occupy the same office space for a decade or more. Wiring errors make such situations worse, but I suspect that even in correctly wired buildings the field levels are higher than in single family homes. Since you have followed EMF research you know that the issue of dose-response is unresolved; that is, we don't know what magnetic field intensity levels may be harmful or even if the risk increases as the intensity increases. It is clear from occupational studies that people in occupations in which they are routinely exposed to even higher field levels of one gauss or more (arc welders for example) do not show a remarkably higher risk of cancer and other diseases. The risk estimate is not as reliable as those of the residential studies since the numbers of exposed individuals are smaller, but at least it seems there is no dramatic increase, as would be expected with most toxic chemicals and similar exposures. I agree with you that it would be worthwhile to do an epidemiologic study in an urban setting that included such high exposures if it is possible to identify people exposed to these levels in large enough numbers and control for exposure differences due to things like unbalanced load in the phases of the wiring. Regards, Bob
Reply from Alex: Dear Bob, Well I don't have time to make a cause of it in spite of my fears, and as you say my ex-wife is ensconced in a rent controlled apartment she will never leave. I understand the mixed results on the dose issue, but I still don't see an awareness in the literature anywhere of just how strong a field we are talking about in some urban environments. I don't see the point of even studying residential levels of 6 milligauss when some people live in a field up to 20 times as strong. Thank you for your response, the first I have had to any letter I have written on the subject. Alex
Reply from Dr. Robert Goldberg: Dear Alex, I think your point is well taken, but consider the difficulties inherent in doing an epidemiologic study of people exposed to higher field levels in an area like New York city. As you pointed out, high field levels are likely to result from unbalanced phase wiring and major feed lines running through specific locations in the buildings. There is no easy surrogate exposure estimate like wire code that can be done from outside the building, so you would have to take magnetic field measurements in each individual apartment, then decide which rooms to use for estimating average exposures. That not only increases the cost greatly (and at present there is little funding for EMF studies in the US), but requires permission of the apartment dweller and the landlord to enter the apartment. Landlords are likely to be quite resistant to having measurements made that might scare their tenants, make them ask for correction of wiring errors or changes to lower field levels, or cause them to initiate litigation based on health concerns. I think you might have a difficult time getting cooperation to collect enough measurements for a decent study population. Regards, Bob
October 23, 1999
Australia
I currently reside in Australia and am in the process of building a new home in a new estate that is being established here in Melbourne. At this point in time there are about 40 homes that have been built. A proposed substation is being contemplated with the relevant Authorities. It will cosist of a 220KV entry point to 2 step-down transformers then feeding about 8-66KV lines around the establishment and through to various other areas. Council here is very concerned about releasing a planning permit to this private power company at the moment considering other potential sites that they can use to built their utility and the eviromental impact on our estate. Although the power company continues to pursue the issue that running additional power lines elsewhere is difficult if not impossible because of easement requirements. I'm very much concerned about this proposal considering the close proximity to residents in this estate. The substation will be built approxiamately 30 Metres from the nearest home. Obviously the other issue is the overall effect of this installation on mine and other properties in this Area. Do you know if sub stations are built in Residential areas as this will be in the US? If at all possible, could I forward to you the planned layout of this site and source your opinion? Yours thankfully, Jerome
Reply from Dr. Robert Goldberg: Dear Jerome, The situation that you describe is not very unusual in the US, at least in older urban neighborhoods where the substations were built 20 years ago or more. I don't know if practices have changed with more recent information, but in Philadelphia we have substations of the type you describe. The major concern for substations seems to be keeping children and others out of the area with effective fencing to avoid risk of shock and damage to the facility. In epidemiologic studies, residential proximity to a substation has been used as an indicator of EMF exposure. For example, Wertheimer and Leeper (Int J Epidemiol 11:345-355, 1982) considered residing in a home within 50 meters of a substation as "exposed" and Coogan and Aschengrau (Arch Environ Health 53(5):359-367, 1998) defined "exposed" as living within 152 meters of a substation. These distances, like studies that have used distance from a powerline, are fairly arbitrary since we have no clear evidence about what is a "safe" distance and actual exposure levels will vary somewhat depending on the load and line configuration at the substation. All I can suggest is that there is likely to be some added magnetic field exposure associated with the substation, at least for those living near the facility. I have no idea about regulations in Melbourne (is there any "right-of-way" provision for powerlines?) so I don't know what your utility will do about relocating the substation further from residential areas. In the US there is a concept of "prudent avoidance" which some of the utilities follow, and they will manage the field levels on new construction if it doesn't add much to the cost to avoid possible risks, recognizing that the evidence is not sufficient to have a clear idea that such measures are absolutely needed. Even if the substation can not be relocated, there are some measures that can be taken to get optimum cancelation of the fields around the substation and minimize the intensity of the exposure. If you get into a protracted discussion with the utility, or just want to inform yourself about what is known about possible risks associated with living near utility distribution facilities, you may want to look at our EMF Health Report as a source of objective informaton on the scientific studies in this area. Regards, Bob
September 15, 1999
USA
Do you find there is any connection between water bed heaters/electric blankets, and breast cancer. I was diagnosed in March and now am too afraid to sleep in my waterbed or to use an electric blanket. Thank you for your insights, Teresa
Reply from Dr. Robert Goldberg: This is an area of considerable theoretical concern but very little hard evidence. Because breast cancer is usually a hormone dependent tumor in its initial phases, the possible affect of EMF in disrupting melatonin patterns could have an effect on breast cancer incidence. This has never been shown in women however (there are some studies linking EMF to male breast cancer) which is perhaps not surprising since breast cancer is a relatively common form of cancer and likely to have many causal factors. A few studies have been done on use of water bed heaters and electric blankets (mostly using reproductive effects as an endpoint, which is easier to follow because any effect would occur sooner after exposure) and the results have been unclear. The biggest problem seems to be that people using such devices are exposed to a wide range of EMF levels depending on the location of the heater coil in the bed, the temperature setting and number of times it comes on in the night, and similar variables. There is also no evidence to indicate that if you have had cancer additional EMF exposure will make it worse. Again there are theoretical reasons to think this could be the case, but no evidence in the few studies that have looked for it. I generally advise people concerned about EMF exposure to avoid it when it is easily done. Perhaps you could use your blanket and bed heater to preheat your bed and turn them off during the night. You should realize that the possible risk of EMF exposure in this case is unclear, and your decision will be based on your personal "comfort level" based on the limited information available. Regards, Bob
August 19, 1999
Malaysia
I am a university student in Malaysia majoring in electrical engineering. Recently I am doing a research on the development of alternating current. There are some doubts that I would be grateful if you can furnish me with the relevant information, that is the comparisons between American and British power standards. As far as I know, American uses 60 hz while in British standards, 50 hz is being used. And may I know if the founder of alternating current is Nikola Tesla. I would be deeply grateful if you can furnish me the relevant information.
Reply from Dr. Robert Goldberg: This is all vital information for an electrical engineer. As electric power technology developed in the US, Nikola Tesla proposed a two-phase AC system in 1888 that won out over the DC system promoted by Edison Systems. In 1882, Thomas Edison had opened the first public generating station on Pearl Street in New York City (a 3-wire, 220 volt DC system) to provide power for incandescent lighting and DC motors. Tesla's AC system had some major advantages, the most important being the ability to send large amounts of current over fairly small lines by increasing the voltage into the kilovolt range and then transforming it back down to 110 V for domestic use (there is no easy way to transform DC). Early systems operated at various frequencies (25, 50, 60, 133 Hz), and 50 Hz won out in Europe and much of the rest of the world. The 60 Hz frequency used in the US, Canada, Brazil, and Japan, results in greater transmission loss due to higher reactance at 60 compared to 50 Hz, but motors generators and transformers can be smaller at the same rating, and flicker with fluorescent lights is less obvious. There are still many different frequencies used around the world in special applications (e.g., 16 2/3 Hz on some European electric rail). My wealth of information on this subject comes courtesy of Lou Vitale (VitaTech Engineering, Montclair, VA) an EMF Health Report reader who was kind enough to send me an excellent introductory chapter on the history of electric power systems from the textbook "Power Systems Analysis and Design" by Glover and Sarma (PWS Publishing Co.). I recommend it for a very clear discussion. Regards, Bob
August 17, 1999
USA
Is there a distance that is considered safe between a high voltage line and a housing development that builders must adhere to, to reduce/eliminate the cancer risk or other kind of health problems? Does it make a difference if there are other houses between? Thank you for your time. Karen
Reply from Dr. Robert Goldberg: Dear Karen, As you might guess, there is a complex answer to your simple question. I addressed the basic issue of estimating health effects in an article I wrote for the EMF Health Report, Volume 4, Number 5, September/October, 1996, "THREE COMMON QUESTIONS FROM THE REAL WORLD: ONE SCIENTIST'S ANSWERS" which is available for download on our web site (go to the bookstore page, http://infoventures.com/cgi-bin/web_store/web_store.cgi, and select "Articles from the EMF Health Report"). In brief, you can determine magnetic field levels by measurement, you can estimate them according to the current load on the line and geometric distance, you can compare the resulting exposure to average levels for US homes, but you cannot say with any confidence that a given level is safe or unsafe. The magnetic field level depends on current rather than voltage and drops off rapidly with distance from the lines. Houses between you and the powerline would have little effect on the magnetic field level (they would shield the electric field to some extent) other than to increase the distance to the line. As far as I know, there are no standards beyond requirements for a right-of-way that affect builders. Many developers will offer land near powerlines to the community for schools or recreational facilities because the land is harder to sell for homes. This issue is a difficult one to address for property issues. The feature article for the next issue of the EMF Health Report is written by Dr. Jack Adams, an engineer who has been working for the California Health Department developing a computer program that takes into account economic and health effects issues in providing a quantitative estimate of the costs and benefits of taking various measures to reduce fields from power lines. Regards, Bob
August 16, 1999
USA
I recently had a hair analysis test done and learned that my body has a excessively high levels of uranium, tin and titanium. I am having my well water tested. From 1989-1996, I lived near power lines. Could they have produced the high levels of these chemicals in my body? I am 48 years old and have been plagued with health problems for the past 10 years. Could the power lines have caused these problems? I have not been diagnosed with cancer. In fact, I have not been diagnosed with anything. I have suffered from depression, chronic pelvic pain (following a hysterectomy-there is no medical reason for the pain), fatigue (complete lack of energy or stamana), hormone imbalances (I know that is due to the surgery) and 2 years ago developed arthritis. What can you tell me? Thanks for your help. Linda
Reply from Dr. Robert Goldberg: Dear Linda, There is nothing in the research that I reviewed that suggests EMF exposure has the effect of increasing levels of metals in the body. The only possible association I know of is the mostly theoretical work by Dennis Henshaw (H. H. Wills Physics Lab., Univ. of Bristol, Bristol BS8 1TL, UK) who has hypothesized that electric fields from powerlines may concentrate pollution from the air. He has some experimental results to back this up, showing increased concentration of radon daughter products and bacteria around electric lines. You suggested well water as the source of the metals, but if it is atmospheric dust (or was in the area you lived in 1989-1996) then there is that possibility of an EMF involvement. Henshaw's theory is controversial however, since others argue that the electric field from power lines couldn't make a signficant contribution to deposited particles at ground level. If you are interested in learning more about Henshaw's theory, there are papers of his on his website, we have abstracts of his published research in BENER and in the EMF Database, and he wrote a feature article in the EMF Health Report in March/April 1998. Many of his papers and papers about his theory can also be found in MEDLINE. Regards, Bob
August 10, 1999
USA
My name is Rachel, and I recently miscarried twice. I have two wonderful children from a previous marriage. During the time that I was pregnant with them, I never sat at a computer. Their father and I divorced. I met my current husband on the net. We talked on here for hours a day. He finally came over in December of last year and we married. He loves my children as his own, but I want to give him a child of his own. He wants that very much also. About a year ago I started working as a Receiving Coordinator for a major logistics company, and now I use a computer all day, everyday, at work. I spend, between home and work, about 45 hours a week in front of this screen. When we lost the first baby, I thought that it was just fate. We mourned the loss, but the baby was lost at about 8 weeks, and it seemed that it could have been a "false alarm". I had not been to my doctor yet, and was depending on a home pregnancy test for the answer. I feel that I was actually pregnant because I had many symptoms that I had had with my two other children. When I found myself pregnant again, my husband and I were ecstatic. I got to the doctor as soon as I could get an appointment, but a week after his office confirmed the pregnancy, I started spotting. They did an ultrasound. I could see our "perfect" little baby, but there was no heartbeat. We had lost another child. In my search for answers following this loss, I got on the net. That is when I found the articles about ELF/VLF radiation and the idea that electro-magnetic fields from powerlines and such might cause miscarriage or birth defects. My desk sits out in the middle of a huge warehouse right next to the fuseboxes and right next to about a dozen huge transformers used to charge the forklifts and order selectors. I am surrounded (within ten feet) by three different terminals, including my personal terminal that I use constantly. After reading the articles I read, I am frankly scared to sit in the midst of all this electronic equipment if I become pregnant again. My husband and I are discussing my possible resignation should we (when we) conceive again. Am I just being paranoid, or could there be some solid truth behind my fears. Thanks, Rachel.
Reply from Dr. Robert Goldberg: Dear Rachel, At the present time there is a great deal of uncertainty about the possible health risks of exposure to EMF, and increased risk of spontaneous abortion and birth defects is one of the more uncertain areas. Work with computer monitors was a possible risk factor that was examined in research studies about 10 years ago. For the most part, more recent evidence suggests little or no increased risk once stress factors associated with the work itself (rather than the EMF) are controlled for. As you describe your work situation however, it appears that you may well be exposed to relatively high magnetic field levels from the building wiring and adjacent equipment. Fork lifts draw a lot of power (fork lift operators are one of the occupations with unexpectedly high EMF exposure) so the charger is likely to use a lot of current. Your magnetic field exposure will depend on the amount of current going through the lines near your work area and your distance from them. If you wanted to check directly, there are inexpensive gauss meters that will tell you if the areas are above the levels common in office work places (5-10 milligauss). It is hard to guess on exposure, but I would not be surprised to find your exposures are well above that level. If your exposure levels are unusually high, it is still not possible to determine if that is a factor in your fertility problems, but it may be a source of concern to you. Since you discovered our web site, you probably have done some reading on the EMF issue and realize the complexity of assessing the risk. Many people, faced with the uncertainty, choose to limit their exposure. If you are concerned, you may find that the information we make available in our EMF Health Report is useful in making a decision and keeping yourself informed about the issue in the future. Regards, Bob
August 9, 1999
USA
I am doing some research on the "police radar guns causing cancer, testicular cancer, to be specific". Can you tell me of any studies that may have been done? Or where I may obtain information on this subject. I thank you in advance. Monica
Reply from Dr. Robert Goldberg: Dear Monica, In our database of research on electromagnetic fields (described on our web site), we have about 20 papers that deal directly with the issue of hand-held traffic radar guns used by police, and a broader range of papers (about 50) that discuss similar types of radar exposure in the military, air traffic control, etc. These include detailed summaries of the content covering occupational health and safety reports, preliminary epidemiologic evaluations, and studies of the exposure levels experienced under various situations. A couple of these reports are from recent issues of BENER and could be purchased on our web site, but most are from earlier issues. The best way to access them would be to request a custom search of the EMF Database which would cost $325.00, including the first 25 abstracts, with additional abstracts at $2.00 each. If you wanted to access a study or two specifically on testicular cancer you should be able to find it on a general biomedical database like MEDLINE. Please feel free to contact me if I can help. Regards, Bob
August 1, 1999
USA
I have just found out that in Forney, Texas, where we are contemplating buildling a new home, there will be 3 new electric power generating plants, all within 5-7 miles from our new area. Can you tell me what the risks of living near these plants might be? Please hurry with any information you may have as we are to sign our papers soon and I do have some concerns and although I do not want to over-react, I certainly don't want to spend $160-200 thousand dollars if there should be concern and I could build elsewhere.
Reply from Dr. Robert Goldberg: It is very hard to generalize any risk from power plants so far from your proposed home. Aside from possible concerns about air pollution, the electromagnetic field effects from the plants themselves would be undetectable at a distance of a few hundred yards. There may be some effect if transmission lines from the plant are routed through your development and the lines pass near your proposed home. The strength of the fields depend on the current in the line and decreases very quickly with increasing distance from the line, so by "near" I mean within 100 yards or so. If this is the case you may want to get some estimates of the likely maximum magnetic field levels from the utility. The actual health risk of exposure, assuming you are within this distance, is itself very hard to determine. Our EMF-Link web site is a good source of information on the research into possible health effects, and if you are concerned about the possible risks you may want to take advantage of our EMF Health Report. Regards, Bob
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