Currents of Fear
Original Air Date: June 13, 1995
Written, Produced and Directed by Jon Palfreman
ANNOUNCER: What is your daily exposure to electromagnetic fields? Should you be worried? Tonight, on FRONTLINE, find out, in "Currents of Fear."
NARRATOR: [voice-over] Imagine an environmental agent to which everyone is exposed day and night, an agent that is invisible, odorless and silent, an agent that affects young and old alike, at work and at play. Now imagine that this agent has been linked in dozens of studies to various cancers, but that the authorities have taken no action to protect their citizens. Some people believe this is what is happening now in America. The threat they see comes from the electromagnetic fields produced by the more than two million miles of power lines that criss-cross the country.
PAUL BRODEUR, Journalist and Author: I think there is a major public health hazard here. I think the evidence to date clearly shows it. I think it is unforgivably stupid public health policy to say that before we implement any kind of preventive measures, we should continue to study this for another five or 10 years in the laboratory.
NARRATOR: [voice-over] Omaha, Nebraska, like everywhere, depends on electricity. The Larm family never questioned it, until 1992.
JULIE LARM, Omaha Parents for the Prevention of Cancer: In February of 1992, my oldest son Kevin was diagnosed with acute lymphocytic leukemia. That very day, in tears, I wanted to know what caused this cancer, because I was afraid for all of my children.
NARRATOR: [voice-over] Julie Larm took Kevin to the Omaha Children's Hospital to be treated. There she encountered other children with cancers, like Jonathan Hendricks, and his mother, Dee. Dee was startled by the number of kids at the clinic with cancer.
DEE HENDRICKS: In going through the oncology clinic here in Omaha at Children's Hospital, I was blown away, in fact, I was in tears by the amount of other children that were suffering from cancer. I could not get out of my mind the faces, all the other bald-headed babies. But I knew, instantly, that this was not a normal thing going on. I wondered what it was in my neighborhood or in Omaha that could have possibly caused my son to have cancer. And driving home one night, I noticed that there were huge transmission towers that were scattered throughout the neighborhood.
NARRATOR: [voice-over] Julie and Dee became friends, and soon were contacted by other concerned citizens, like Adrian.
ADRIAN DENDINGER: I was diagnosed with purpura hemophilia, I was diagnosed with Addison's disease, I've had seven unexplained miscarriages. I have been diagnosed with cancer. I've had a complete hysterectomy. My parents lived 50 foot from a 160-volt line tower. We grew up, as children, playing, having tea parties, whatever, under that.
NARRATOR: [voice-over] Their suspicions that power lines had something to do with all these health problems were apparently confirmed when, a few months later, they saw a segment of the CBS News magazine, Street Stories, about the dangers of electromagnetic fields, or EMFs. The program featured a school in California where teachers had abnormally high cancer rates, and a landmark Swedish study showing that children living near power lines had up to four times the risk of childhood leukemia.
CBS NEWS CORRESPONDENT: ["Street Stories," CBS News] Immediately after this landmark study was released, the Swedish government and the power companies accepted the connection between electromagnetic fields and cancer.
NARRATOR: [voice-over] Also interviewed was a senior public health official, Dr. David Carpenter.
DAVID CARPENTER, Dean, School of Public Health, SUNY Albany: ["Street Stories," CBS News] I feel very strongly about this issue, because I really feel people are dying from exposure to magnetic fields that could easily be avoided.
JULIE LARM: So I called the health department the next day. They told me I had to gather the names and diagnoses for as many children as we could before they would start an investigation. So we began a telephone line of calling parents that we knew, and then they would, in turn, call parents, and we got a list of 11 children, that lived within one mile of the substation, that had been diagnosed with cancer within the last seven years. So then we called the health department back, and they, in turn, then did an investigation.
NARRATOR: [voice-over] While they waited for the health department, they began plotting cancers on a map, and reading everything they could find on the health effects of magnetic fields. One author that caught their attention was pioneering environmental journalist Paul Brodeur. He had written about similar EMF cancer clusters in Connecticut and California.
PAUL BRODEUR: My name is Paul Brodeur. I've been a staff writer at The New Yorker magazine for the past 35 years. I was the journalist who first alerted the nation to the health hazard posed by asbestos.
NARRATOR: [voice-over] For Brodeur, EMFs were simply the latest of a series of environmental toxins that industry and government had tried to conceal from the public.
PAUL BRODEUR: It's pervasive. You literally have millions of unsuspecting men, women and children exposed to power frequency magnetic fields that have already been associated in dozens upon dozens of studies conducted and published in the peer-reviewed medical literature, levels that are associated with the development of cancer. Never before has there been this much epidemiological evidence of the carcinogenicity of any agent, and that evidence subsequently declared to be invalid, and that agent subsequently declared to be benign.
NARRATOR: [voice-over] By the time Julie, Dee and Adrian met with the Nebraska health department, they had become convinced there was a serious problem with the power lines in their neighborhood, and they were in no mood to be patronized.
JULIE LARM: We used your map to put our dots on. These are the four ZIP codes, outlined in yellow. These are substations, okay.
DEE HENDRICKS: Something's going on in this neighborhood. There's too many dots that represent families that are being torn apart by cancers. There's too many 17-month-old bald-headed babies in the neighborhood, and we're going to scream until someone figures out what's going on in this neighborhood.
BRYAN RETTIG, Nebraska Department of Health: You know, the truth of the matter is, is that almost without exception, cancer cluster investigations don't come up with anything. They don't find a risk factor or, you know, a series of risk factors that might be responsible for-- for what-- you know, for the increase in the number of cases of cancer.
NARRATOR: [voice-over] When the head of the health department failed to turn up to this meeting, Adrian became angry.
ADRIAN DENDINGER: Those are people. My sister, dying of brain cancer. I've watched her rot in Mayo Clinic for a year. And then a head of a health department doesn't come to the meeting. That's baloney. We get lied to, we get ignored, we have to go get our own information, we have to make our own maps, we have to find out about substations. That is not what our elected officials are for. We're getting screwed from both sides.
NARRATOR: [voice-over] The Omaha mothers' concerns are shared by this man, Dr. David Carpenter, dean of the School of Public Health at the State University of New York-Albany. Carpenter has been convinced for almost a decade that EMFs pose a genuine risk.
Dr. DAVID CARPENTER: In my judgment, they are dangerous. Up to 15 percent of all cases of childhood cancer might be attributable to exposure to magnetic fields from the power lines in the street.
NARRATOR: [voice-over] But not everyone agrees that power line magnetic fields are dangerous. The group most skeptical of Carpenter's claims are engineers and physicists, who argue that the laws of electricity and magnetism, discovered a century ago, are among the best understood theories in science--
MUSEUM STAFF MEMBER: So those sparks are being produced by about 1.5 billion volts of electricity, but I can touch the inside, run along the inside with my bare hands.
NARRATOR: [voice-over] --so much so that museum staff entrust their lives to those principles every day, demonstrating them to children.
ROBERT ADAIR, Ph.D., Yale University: There's probably nothing on earth, or in the universe, that we understand as well as electromagnetic fields, and the interaction of electromagnetic fields with matter, including biological matter. All of chemistry and almost all of biology, excepting a few gravitational effects, are electrical.
NARRATOR: [voice-over] Bob Adair and his colleague, Bill Bennett, are professors of physics at Yale University. A few years ago, they became interested in this area, and the more they studied it, the more skeptical they became. The notion that power line electromagnetic fields could cause disease seemed, on the face of it, to be scientifically impossible.
WILLIAM R. BENNETT, JR., Ph.D., Yale University: The thing that struck me as most puzzling about it is that the fields these people are dealing with are absolutely minuscule. They're talking about fields of two or three milligauss, fields that are 1/200th or so of the earth's magnetic fields.
NARRATOR: [voice-over] Magnetic fields are measured in milligauss. The fields recorded in most homes are of the order of a few milligauss, at most. Yet, as every school child knows, we live in a magnetic field, the earth's magnetic field, which causes a compass needle to point north, and this field is hundreds of times larger. In America, it is about 500 milligauss. The earth's field, physicists argue, would totally dwarf those from power lines.
PAUL BRODEUR: There is absolutely no reasonable biological comparison between the earth's magnetic field, in which we evolved as human beings and which, as some people think, is responsible, at least partially, for the way our brains and central nervous systems develop, and the power frequency fields, which have only been with us, really, in a meaningful way for 50, 60, 70 years.
The magnetic field given off by power lines alternates to and fro, 60 times a second, to the rhythm of a 60-hertz alternating power. When you're standing underneath a power line, every cell in your brain and body is entrained to the rhythm. Well, that rhythm is going 60 times a second.
NARRATOR: [voice-over] But physicists have calculated the force this oscillating magnetic field could exert on moving charges in the body, and the electric currents it could induce, and concluded they are tiny, thousands of times less than the effects of the body's own heat bouncing molecules around.
ROBERT ADAIR: It's completely lost in the noise. The oscillation from the magnetic fields is absolutely minute compared to the general thermal oscillations. They would be a little like, let us say that you have a windstorm, and an erratic windstorm, where the wind's blowing all over the place, and somebody calls -- your neighbor calls up and said, "Your cat is breathing on my tree. Since he breathes in and out, that causes the tree to be pushed in and out, and that might damage the tree." Well, you wouldn't take it very seriously.
NARRATOR: [voice-over] Physicists found it even harder to see how such a tiny field might cause cancer. Cancer is usually caused when very energetic radiation or some chemical agent directly breaks or rearranges DNA. Adair calculated that power line fields were millions of times too small to do this.
John Moulder is a radiation biologist, a specialist in how radiation can cure or cause cancer.
JOHN MOULDER, Medical College of Wisconsin: Certain types of electromagnetic sources, the high energy ones -- x-rays, cosmic rays -- are capable of actually breaking bonds in biological material and cells, and it's that breaking of bonds, specifically breaking of bonds in the genetic material, that can cause cancer.
NARRATOR: [voice-over] This kind of radiation, ionizing radiation, lies at the high end of the electromagnetic spectrum. Vibrating at very high frequencies, 10 billion trillion times a second, ionizing radiation like gamma rays from radioactive fall-out, cosmic rays from space, and medical x-rays can all cause cancer. But at lower frequencies, the radiation no longer has the energy to break DNA.
JOHN MOULDER: Within the optical frequencies, the photons have enough energy to excite electrons and molecules, and that's the basis of how flowers grow and of how we see. Once we get down a little bit lower, down to lower frequencies now, into infrared and then into the microwaves and radio frequencies, the photon energy isn't even enough to do that, but it can heat, and that's how a microwave oven works. It works by heating molecules. As the frequency gets a little lower, we now pass through the frequencies used for cellular phones, then television and FM radio, and then ever lower, the ones used in broadcast AM radio. Somewhere around where AM radio is, the frequency is so low, the photon energy is so low, we don't even get heating.
NARRATOR: [voice-over] Twenty-four hours of every day, we are bathed in electromagnetic energy from all parts of this spectrum. Right at the low end, one million times less energetic than AM radio, are power line EMFs. The fields from these lines vibrate only 60 times a second. This frequency is so low, and the energy in the field so tiny, that all other natural sources dwarf it. Physicists have calculated a person standing under a power line at night would get some 10,000 times more electromagnetic energy from moonlight than from the power line. Such arguments led the 45,000-member American Physical Society to release a report last month saying that cancer fears were "unfounded."
PAUL BRODEUR: Who says that the lower frequencies don't operate in another way to cause cancer? Who says that they all have to act in the same way? Who says they do? Ludicrous. I mean, what kind of mind set is that? Well, I fear it's the mindset of the American physicist. The fact that the physicists don't want to believe that should not, in any event, be the engine that drives public health policy in the face of all this epidemiology, which is the only valid tool we've ever had to take preventive public health measures. It was through epidemiology that we learned that cigarette smoking was hazardous, through epidemiology that we learned that asbestos inhalation was hazardous, through epidemiology that we've learned that virtually every one of the environmental carcinogens that we know today, and against which we've taken action, has come to light through epidemiology. So the physicists are going to tell us "No, forget epidemiology, let's go into the lab"? Give me a break. You know, when have they ever discovered anything about biology?
INTERVIEWER: Do you think they should stay out of this debate?
PAUL BRODEUR: No. I think everybody should get in to the debate, the more the merrier. But I think it's ludicrous for physicists to try to pretend that they know about biology, when they don't. And the example I gave, that the last time they got involved in a major public health controversy, it was to assure the American people that no possible hazard could come from radioactive fallout, goes to show you how stupid and wrong they were about ionizing radiation.
NARRATOR: [voice-over] Traditionally, epidemiologists studied epidemics. Working back from an epidemic, usually an infectious disease, they tried to find a cause. Great successes of epidemiology include the major infectious diseases, and modern plagues like AIDS. But increasingly, epidemiology has been used to link environmental toxins with disease, and this has proved more controversial. Here, where the effects are strong, most scientists concede that epidemiology alone is sufficient to prove a serious public health risk. In heavy smokers, for example, the risk of disease, the so-called risk ratio, is 10 to 20 times that of a nonsmoker. Similarly high risks were found in studies of asbestos workers. These findings were so striking that even before there was supporting laboratory evidence, many public health officials were convinced that such toxins endangered the public, and advocated preventive health measures.
So if magnetic fields pose similar risks, one might expect that electrical workers exposed to very high fields would get cancer at a significantly higher rate than average. EMF activists like Brodeur claim this is, indeed, the case.
PAUL BRODEUR: The clear preponderance of the occupational studies show that workers exposed to power frequency magnetic fields at home and at work, are developing cancer at statistically significant higher rates than non-exposed people.
NARRATOR: [voice-over] But Brodeur's interpretation of the dozens of epidemiological studies isn't shared by many scientists.
JOHN MOULDER: The first thing you ask is how strong are the correlations when you see them, so my favorite analogy is to cigarette smoking. Cigarette smokers have 10 to 20 times the incidence of lung cancer of nonsmokers. That's a strong association. In the power frequency studies, where we find associations, they've tended to be pretty weak.
NARRATOR: [voice-over] In the EMF studies that found an elevated risk of cancers, risk ratios of only 1.5 to 2 are typically seen.
JOHN MOULDER: The second thing you would look for is, is it consistent? Does everybody find the same thing? All studies, for instance, of smokers showed elevated lung cancer. But with the power frequency occupational studies, you don't see that. Some studies show leukemia elevated, some studies don't. Some show brain elevated, some show that they're not.
NARRATOR: [voice-over] Three recent very large occupational studies produced quite inconsistent results. One found elevated levels of brain cancer, but no leukemia. A second found no brain cancer, but did find a suggestion of a link with leukemia. A third found nothing at all. Many epidemiologists think this inconsistency, combined with such low risk ratios, raises serious questions as to whether there is, in fact, a real risk, or whether all the studies are picking up is statistical noise.
PATRICIA BUFFLER, Ph.D., Dean, School of Public Health, University of California, Berkeley: If it's a low-level risk, you have to be very careful. Epidemiology is not sufficient in and of itself unless you have a situation where you have an overwhelming disease response, and we have a few examples like that. The vinyl chloride monomer story, where a small number of workers developed a very rare malignancy, angiosarcoma of the liver, and were identified as having very high exposures to vinyl chloride monomer in the process of cleaning out some of the reactors. There we had a risk ratio which exceeded 200.
NARRATOR: [voice-over] There were also issues about whether all of the workers in these studies had really been exposed to magnetic fields. While serving on the Oak Ridge panel investigation into EMFs, Bill Bennett read dozens of epidemiological papers, and found some were quite misleading.
WILLIAM R. BENNETT, JR.: There was one report published that referred to an epidemic of male breast cancer among telephone linemen in New York State, in the phone company. When you look at the data, you find that although this produced at a relative risk of something like 6.5:1, there are only two cases that were recorded, and they weren't linemen at all, they were actually office workers. So that somehow, on the basis of these two cases, one is led to believe that there was a serious problem involved.
NARRATOR: [voice-over] And Bennett realized there were other occupational categories that epidemiologists seemed to have virtually ignored. Going down to the Amtrak station, he measured a 50-milligauss magnetic field, even with no trains, and he decided to do an experiment.
WILLIAM R. BENNETT, JR.: I took data coming from Washington to New Haven at two-second intervals with a gaussmeter, and what I noticed in that result was that the magnetic fields were enormously high, compared to most of the epidemiological studies.
NARRATOR: [voice-over] On his journey, he measured peak magnetic fields as high as 600 milligauss.
WILLIAM R. BENNETT, JR.: There hasn't been a major epidemic of leukemia among electric railroad commuters, to my knowledge, or among workers on electric railroads who would be exposed to the fields even longer.
NARRATOR: [voice-over] Last year, one Norwegian study did investigate electric railway workers. It found no effect. But there are other problems that make interpreting the occupational epidemiology difficult. While workers in a substation are exposed to about 40 milligauss, the fields from home appliances can be quite large, as well, especially six inches or less from the appliance.
While these appliances are only on intermittently and the fields fall off quickly with distance, some, like electric blankets, can give long-term exposure. All of this makes the EMF issue far more complex than most epidemiology. As we live in an electric world, with appliances and with overhead and underground cables, virtually everyone is exposed, at home, in the workplace, even in the park. Even the epidemiologists who believe there may be a link with disease fear it may be impossible to prove.
DAVID SAVITZ, Ph.D., Epidemiologist, University of North Carolina, Chapel Hill: The key mode of exposure in the workplace is not notably higher than the key mode of exposure from outside the workplace. So if you have someone who's working, let's say, as an electrician, and look at how much exposure they accrue over their workday, if they go home and use an electric blanket, or perhaps live near certain kinds of power lines, they may actually get an equivalent amount of exposure at home.
PAUL BRODEUR: So much for the claim of the electric utility industry that this is, quote, "junk science."
NARRATOR: [voice-over] Paul Brodeur passionately disputes that the epidemiological studies are flawed, and in a recent book argues that the truth is being concealed from the public. The coverup involves government and industry, notably the Electric Power Research Institute, which funds much of the research. Moulder thinks this far-fetched.
JOHN MOULDER: First of all, they would have to know that a study was going to be negative before they funded it, and second, to repress positive findings in funded studies, I think, would be next to impossible, because you'd have to repress it in this country, you'd have to repress it in other countries, you'd have to repress publications by industry, by government, by academics. I don't think you could do it.
INTERVIEWER: Are you saying they're lying?
PAUL BRODEUR: I didn't say they were lying. I never said they were lying, and I have never claimed, nor do I believe, that anyone of these scientists, or any scientists who are being financed by EPRI or by the utility industries are falsifying their scientific data.
What they are doing, and let's be clear about this, is not lying. They are coming out and they're making public pronouncements about their opinions. Quote, "It is my opinion that there's absolutely no validity in any of the epidemiological studies that have been done so far." That's Patricia Buffler. Madam Buffler is not only a paid consultant of EPRI, she's a paid consultant of the San Diego Gas and Electric Company and has given an affidavit for them in court.
PATRICIA BUFFLER: I've worked with the U.S. Environmental Protection Agency, reviewing their document on EMF, and I've worked with the Electric Power Institute, putting in place their research program. Those are very important activities to participate in, and I think for someone to infer that by virtue of participating in those activities, I have a conflict of interest, is to attempt to intimidate me or others from participating in this public debate.
NARRATOR: [voice-over] Back in Omaha, Julie, Dee and Adrian, dissatisfied with the health department's response, joined a national activists' group, the EMR Alliance.
JULIE LARM: We do believe there is a coverup, and that they have known about the link with electromagnetic fields and cancer for quite some years. Certain individuals have the information and are able to protect themselves and their families. It is not fair that the rest of the public does not have it. They need to tell the truth.
NARRATOR: [voice-over] Last year, Julie got the chance to make her views known to President Clinton, when ABC invited Kevin to the White House for a special children's town meeting. In preparation for the program, ABC filmed Kevin in Omaha.
KEVIN LARM: I just think it's a big coverup. There's just too many kids getting cancer around here. There's 11 kids in this one-mile radius from the substation that have cancer, 11 of them.
JULIE LARM: The night before he was to appear with President Clinton, he became ill out in Washington and had to be hospitalized, so my other son took over for him on the show.
PETER JENNINGS, ABC News: Patrick, you want to talk to the president?
PATRICK LARM, Hometown Omaha, NE, Age 10: I want to ask you his question: "I have heard that recent studies have linked EMFs to childhood cancers. Other countries such as Sweden are passing laws to set standards. As our president, can you help lower EMFs, so hopefully some childhood cancers can be prevented?"
Pres. BILL CLINTON: That's something that we can do something about, but we had a study in 1990 which was inconclusive about it, but you're right, Sweden has concluded that EMFs do lead to higher rates of cancer. So I have asked the person who runs the Environmental Protection Agency for our government to do a review of this and to make a report to me in the near future. We just have to look into it and see whether we think there's honestly evidence there, and if there is, then we have to take action, and we're looking into it. And you tell your brother to hang in there.
Kevin, I hope you're watching this, and, we're praying for you and pulling for you.
NARRATOR: [voice-over] Five days later, Kevin, Patrick and Julie were invited to the Oval Office to talk further with President Clinton.
JULIE LARM: In my heart, I believe President Clinton is sympathetic to the children. After meeting with him, I believe he's sympathetic. But I believe, because of politics and large industries, his hands are tied.
NARRATOR: [voice-over] Two years before Julie's meeting at the White House, Congress had set aside funds, some $65 million, for research to try and resolve the issue. Because of the inconclusive epidemiology, research scientists like Gary Boorman were brought in to investigate EMFs in the laboratory. Perhaps with carefully controlled scientific experiments, biologists would be able to unlock the mystery of magnetic fields. Boorman realized that to get definitive answers, he had to attract first-class scientists.
GARY BOORMAN, Ph.D., EMF Program, National Institute of Environmental Health Sciences: You have to apply the same scientific standards to magnetic field research as you would to any other field. We're trying to get the best investigators we can to bring their resources and their intellect to bear on this problem. It's very difficult. A lot of scientists would rather work on AIDS, breast cancer, or other areas, and they're reluctant to get involved in this field. We're trying to get the best scientists involved, and we're having some luck in that regard.
NARRATOR: [voice-over] One large grant went to the Illinois Institute of Technology in Chicago. They built the largest rodent EMF exposure facility in the world, capable of exposing 3,000 animals at a time.
DAVE McCORMICK, Ph.D., ITT Research Institute: Our budget for this program is a little over $9 million. This building is constructed almost entirely of nonmetallic materials. All the wall and ceiling construction is wood. Temperature, humidity, noise level, light level are all controlled and monitored continuously. The earth's magnetic fields in all the rooms has been mapped very extensively. We monitor the ambient fields of the rooms continuously, so I think it's fair to say we've taken quite great pains to remove any potential confounders from the program.
NARRATOR: [voice-over] Two years ago, the center began a series of crucial studies to see if magnetic fields caused birth defects or reproductive problems, to see if they caused or promoted cancer, to discover if magnetic fields affected the immune system. Unlike humans, who are constantly exposed to 60-hertz magnetic fields, McCormick could ensure that one group of rodents, the control group, would be completely unexposed. Other groups would be exposed to different amounts of magnetic field from 20 milligauss all the way up to a massive 10,000 milligauss, thousands of times the average exposure in most homes. If anything could detect an effect, at least in rodents, these experiments should.
Another exciting possibility that interested Boorman was that the magnetic fields were subtly affecting cancer genes in totally novel ways, as Paul Brodeur had claimed. While power line magnetic fields could not break DNA, some unconfirmed studies had claimed that the fields might stimulate a certain cancer gene, increasing its activity and, presumably, its likelihood of causing cancer.
Jeff Saffer, a young molecular biologist, was intrigued by this possibility, so a couple of years ago he set out to try and validate the experiments. He placed identical batches of human cells into two test chambers. One batch of cells would be exposed to power line magnetic fields; the other would not. Saffer's job was to measure precisely whether this field affected the activity of a cancer gene called the MIK gene. If it did, it meant, in principle, there might be a mechanism by which EMFs could cause cancer.
Saffer knew that he had to be extremely careful. Temperature, humidity, noise and vibrations might affect the subtle changes he was looking for. His first effort failed. Undaunted, he continued systematically searching for something he might have done wrong. These efforts would take nearly two years.
By Spring, 1995, results from the different labs were beginning to come in. The EMF rodent exposure laboratory in Chicago had completed five studies. First, the study looking at whether power line magnetic fields caused fetal abnormalities.
DAVID McCORMICK: We evaluated a total of 3,000 animals. We did complete skeletal evaluations, evaluations of the head, evaluations of all the visceral organs, and that study was completely negative. We found no adverse effects of the magnetic fields at all.
NARRATOR: [voice-over] A reproductive study involving 12 litters from three generations of animals bred under the magnetic fields was also over.
DAVID McCORMICK: The end points we looked at were number of successful pregnancies, number of litters which were actually delivered, number of pups per litter, birthweight, and a number of other parameters to assess the health of the pups once they're delivered, and again, the results of that study demonstrated no effect of the magnetic field on reproductive performance in either sex.
NARRATOR: [voice-over] Two cancer studies using specially bred cancer-prone mice were also finished. Did the magnetic fields promote an already existing cancer? Did the exposed animals get higher cancer rates?
DAVID McCORMICK: Again, we found no evidence that magnetic fields stimulated lymphoma production in either strain. The EMF exposure had no effect.
NARRATOR: [voice-over] Finally, the immunology study also came out negative. One big study is still going on, where rats will spend two years, essentially their whole life, under the magnetic field. This will test for a longer-term chronic effect. The results will be known next year.
Meanwhile, at the Pacific Northwest Laboratories in Washington State, Jeff Saffer had gone to great lengths to discover whether magnetic fields could directly influence the MIK cancer gene. Despite his best efforts, nothing had worked, but he refused to give up.
JEFF SAFFER, Pacific Northwest Laboratory: We went back and used different types of plasticware to grow the cells that were different geometries, different shapes. We tried some higher field intensities, we tried some lower field intensities, we tried different type of serum, we also tried different concentrations, and again, could not find any conditions under which the cells were responsive to magnetic fields.
NARRATOR: [voice-over] Finally, Saffer took an extraordinary step. He actually went to the laboratory of the investigator whose work he was trying to replicate.
JEFF SAFFER: We went to the laboratories in New York City that had done these experiments, used their cells, used their culture vessels, their exposure system, and again were unable to find evidence for change in MIK expression due to the magnetic field.
NARRATOR: [voice-over] Saffer's conclusion was that the effects reported were not real, but probably resulted from inadequate experimental controls. Last month, in the scientific journal Nature, a preliminary report of Saffer's work appeared. The same issue carried a report from a team in Cambridge, England, who had also tried and failed to find any effect. Other studies have recently reported negative results. A study into whether EMFs affect melatonin levels in humans, a hormone that's been linked to breast cancer, found no effect. A large study of pregnant women using electric blankets was also negative. While other experiments are still underway, so far, things don't look promising.
GARY BOORMAN: As you refine your studies, if there really is an effect, the effect should, should increase, it should become stronger, it should become more focused, and if you cannot, with repeated studies and with better studies, you continue not to find an effect or find only marginal effects, then it becomes obvious that there's really nothing there.
NARRATOR: [voice-over] When completed, these studies will help Congress decide what, if any, action to take, but Paul Brodeur doesn't believe laboratory studies should drive health policy.
PAUL BRODEUR: Laboratory studies are not going to be the criteria upon which we base preventive public health measures. We have used the epidemiology as the only viable tool for implementing preventive public health measures. It is the only viable tool.
NARRATOR: [voice-over] But in the face of so much negative laboratory data, can epidemiology alone prove that cancers like the one Kevin Larm has are caused by EMFs? One thing most epidemiologists agree on, even the ones who support a link between EMFs and cancer, is that the kind of lay epidemiology that the Omaha parents have done is unsound. They had identified four ZIP codes in Omaha which appear to have two to three times more cancer than average, and these ZIP codes are criss-crossed with power lines. It looks impressive but for two things. First, according to their map, only three of the cases actually live within 300 feet of a power line, and power line fields fall off to tiny levels within this distance. But there is a second, more crucial weakness to this lay epidemiology. Cancers do not fall evenly across the landscape. Even if there is no carcinogenic agent in the environment, just by random chance, some ZIP codes will get more cases than average. Others will get less. For example, this densely populated ZIP code a few miles away has just five cancer cases, less than half the expected number, and it, too, is criss-crossed with power lines.
PATRICIA BUFFLER: In many of the cluster investigations, where cases are taking place in time and space, these events most likely are happening by chance, and if you draw artificial boundaries around a cluster in time and place, it's like the Texas sharpshooter.
NARRATOR: [voice-over] Epidemiologists like to tell their students the cautionary tale of the Texas sharpshooter.
PATRICIA BUFFLER: He takes his gun, shoots at the side of the barn, and then draws a bull's-eye around it afterwards, and then says "Aha, I have a bull's-eye."
NARRATOR: [voice-over] Drawing artificial boundaries in space and time, such as cancers occurring in certain ZIP codes during certain time periods, can create an illusion of a cluster. In fact, like the sharpshooter's bullets, cancers are usually scattered randomly throughout the landscape. Even scientists who support an EMF cancer link agree it's not valid scientifically.
Dr. DAVID CARPENTER: By statistics alone, it's very possible that there will be a number of cancers in one block and none in the next 10 blocks. And if one wants to try to identify sources of cancer, what one must do is study many, many children.
NARRATOR: [voice-over] That's just what a number of investigators did. Over the past 15 years, a series of residential studies, each involving thousands of children, have been done. The results have been controversial because, depending on how exposure from power line EMFs was estimated, epidemiologists either found or did not find associations with childhood cancer. Like the occupational studies of electrical workers, the typical risk ratios reported in these studies were low, around 2 or less, too low, most epidemiologists felt, to prove an effect.
But in 1992, a landmark study appeared from Sweden. A huge investigation, it enrolled everyone living within 300 meters of Sweden's high-voltage transmission line system over a 25-year period. They went far beyond all previous studies in their efforts to measure magnetic fields, calculating the fields that the children were exposed to at the time of their cancer diagnosis and before. This study reported an apparently clear association between magnetic field exposure and childhood leukemia, with a risk ratio for the most highly exposed of nearly 4.
The Swedish government announced it was investigating new policy options, including whether to move children away from schools near power lines. Surely, here was the proof that power lines were dangerous, the proof that even the physicists and biological naysayers would have to accept. But three years after the study was published, the Swedish research no longer looks so unassailable. This is a copy of the original contractor's report, which reveals the remarkable thoroughness of the Swedish team. Unlike the published article, which just summarizes part of the data, the report shows everything they did in great detail, all the things they measured and all the comparisons they made.
When scientists saw how many things they had measured -- nearly 800 risk ratios are in the report -- they began accusing the Swedes of falling into one of the most fundamental errors in epidemiology, sometimes called the multiple comparisons fallacy.
JOHN MOULDER: The problem is, when you do as they did, hundreds and hundreds of comparisons, something in the neighborhood of 800 different comparisons, by the standard way we do statistics, we would expect 5 percent of those to be statistically elevated and 5 percent to be statistically decreased. And now you have a problem. If you find, by one measure of exposure, that leukemia is up in a group of kids, is that real, or is that the result of just random noise in the system?
NARRATOR: [voice-over] In their thoroughness, the Swedes had created their own version of the Texas sharpshooter problem. Even if nothing is going on due to power lines, if you measure hundreds of risk ratios, they will scatter by random chance around a mean of one. Some will be above, and some below. Risk ratios below one suggest that EMFs protect against cancer, above one, that they increase the cancer rate. But the published article focused only on the strongest positive risk ratios. The summary highlights a nearly fourfold increase in risk of childhood leukemia. This is what the press picks up and the public hears.
JOHN MOULDER: It is not scientifically reasonable to do all the measurements, but then only pick out the ones that give you the answer you want for publication. If I dredge through their original report, I can find situations which, looked at in isolation, without looking at the rest of the report, that if that was the only data I gave you, I could claim that that proved that power lines protected children against childhood leukemia.
PATRICIA BUFFLER: It is analogous to the Texas Sharpshooter. What we're searching for in any research is truth, and that search for truth argues for being rigorous, having clearly documented your methods, and not withholding any information, not using the information in a selective way.
NARRATOR: [voice-over] How many of the EMF studies commit this error is unclear. Original contractors' reports are rarely available. Yet the issue is fundamental. Outside of epidemiology, most scientists are unanimous. You cannot confuse a study that tests a hypothesis with one that generates them.
ROBERT ADAIR: Epidemiologists should decide what they are going to look for, and write it down before they make the search, just what they're going to look for and just how they're going to look for it. Then, after they make their analysis, they will find two sets of things. They will find answers to the questions they have asked, and now we have a situation where one can analyze properly the statistical significance of those answers. They will also have answers to questions which weren't asked. Odd things may show up, and that's very interesting, too, but we separate those in another category. We call those hypothesis-generating experiments. And if you want to say whether that's really a real result or just a fluctuation, then you must do a second experiment were that is on your list of things to look at.
PAUL BRODEUR: Yeah, this may be a weakness in the album study. I'm not familiar with it myself. And there are weaknesses to be found in all of the epidemiological studies. You can take any given epidemiological study -- and I saw the asbestos industry do this time and again -- as it comes over the horizon, gets published, you can shoot it down with all kinds of stuff. They're trying to shoot down the Canadian study now. But the totality of these studies suggests a pervasive major public health problem that needs to be dealt with, and that I believe will have to be dealt with, because the American people will demand that it is, that it be dealt with.
NARRATOR: [voice-over] In the face of negative biology and contentious epidemiology, what should lawmakers do to protect people from a risk that may well not be there? Peter Vahlberg is an expert in risk assessment. One thing, he says, is certain. Even supposing there is a risk, the fact that it has been so hard to prove that power line magnetic fields cause cancer means that, by definition, any risk cannot be very large. Even assuming the Swedish study were true, the increased risk to children of getting a very rare cancer like leukemia is of the order of one in a million. Would moving them to another school make them safer?
PETER VAHLBERG, Ph.D., Harvard School of Public Health, Gradient Corp.: On the one hand, you might argue that if you believe there is an elevated risk from an adjacent nature of the power lines, that you could move the children out, but if this, in fact, involves putting them on a vehicle such as a bus and driving them a mile or so, we know from real actuarial statistics that being on a bus does carry some real health hazards, in terms of injury and death. The EMF risk is likely very small, it's hypothetical on several bases, whereas the risk from getting in a car is very concrete, it's very real, we can actually appreciate that, and we know how to calculate that. And to say that you're going to incur these concrete risks in order to avoid this very low hypothetical risk doesn't seem to make a lot of sense.
NARRATOR: [voice-over] And in fact, the Swedish authorities now agree. On reflection, they decided not to make any policy changes based on the 1992 study.
So should President Clinton follow the Swedes and do nothing? Not according to David Carpenter.
Dr. DAVID CARPENTER: There's too much smoke here. There's got to be a fire. While I admit that the proof is not 100 percent, there is consistency in correlation between leukemia and brain tumors and exposure to magnetic fields, both in residential and occupational settings. So I do not believe that doing nothing is appropriate.
NARRATOR: [voice-over] Amidst the public controversy, for Dee and Julie there is good personal news. In a happy reversal of fortune, both Kevin's and Jonathan's cancers are in remission, and their future looks very promising. Thanks to major advances in childhood cancer therapy, nearly two-thirds of childhood cancers are now curable. But they have not changed their belief's about EMFs.
DEE HENDRICKS: Our human body is very complex. It will be years before scientists understand it more, and they will never understand it completely, the way that God put us together. There is significant studies that do show that electromagnetic fields make changes, and that's what I believe.
NARRATOR: [voice-over] And do they have any doubts they're on the right track?
JULIE LARM: No
ADRIAN DENDINGER: Not at all. I'm 100 percent sure.
NARRATOR: [voice-over] Rightly or wrongly, power lines are now part of a long list of environmental agents that the public fears. While unproven, these fears, once established, are hard to erase.
PETER VAHLBERG: Reducing anxieties is far, far more difficult than inciting anxieties. I think it partly hinges on a difficulty that people have with understanding numbers. I mean, you can say the risk is high, the risk is low, and so forth, but the quantitative differences are difficult for people to appreciate.
NARRATOR: [voice-over] But why would people fear power lines more than established risks, such as smoking and driving?
JOHN MOULDER: What are the big risks that people seem to be totally unafraid of, like driving a car, versus the small risks they appear to be very afraid of? The differences seem to be people are less afraid of risks they think they control, and they're less afraid of risks that they understand, so the things that people are most afraid of is things they can't control and don't understand, and certainly power lines fall right in that category.
NARRATOR: [voice-over] A society must pay a price for its fears, whether they are real or imaginary. The power line controversy is costing an estimated $1 billion a year, money, critics argue, that could be much better spent elsewhere.
ROBERT ADAIR: The total cost to our society with this nonsense, this unreasoning fear of electromagnetic fields, is a serious drag on our economy and, in some sense, on our civilization. And it's like the little boy who calls wolf all the time, and one of these days a real wolf is going to come, and people are going to be so used to the imaginary wolves that they're going to miss the real wolf.
Copyright (c) 1995 WGBH Educational Foundation