Scientific attention continues to focus on EMF. One study came out shortly after the Oak Ridge report and received tremendous attention. As Brodeur reported in The Great Power-Line Cover-Up, "On September 30th of 1992, the wind went out of the utility industry when officials of Sweden's National Board for Industrial and Technical Development formally announced that they intended henceforth to 'act on the assumption that there is a connection between exposure to power frequency magnetic fields and cancer, in particular childhood cancer.'"
This action was prompted by two studies at Sweden's Karolinska Institute, one of childhood leukemia and the other of occupational exposure and brain cancer. Both claim to have found a connection between cancer and EMF. These studies contradicted two British studies released in 1990 and 1991 that found no such connection, yet the British studies go unmentioned in Brodeur's work.
Indeed, they are virtually unmentioned anywhere in the popular media. A Nexis computer database search a few months after the Swedes made their announcements found that while 81 media outlets mentioned the Swedish studies, only one mentioned the two British ones, even though the British studies appeared in a peer-reviewed medical journal (the British Journal of Cancer) while the Swedish study was released directly to the media with no review. Rather than go the usual route of peer review and publication in a medical or science journal, the Karolinska Institute did an end run around the usual careful if stodgy system by simply handing an abstract of their findings over to reporters at a San Diego conference on EMF. Many members of the media appear to be unaware that epidemiological studies often conflict, and simply took--or at least represented in their articles--these to be essentially the final word on the subject.
Though the popular media refer to these Swedish studies as more or less definitive, EMF authorities do not. In a letter to Science in July 1992, the Oak Ridge panel noted glaring inconsistencies between the two Karolinska studies and an earlier Swedish study from 1986.
The 1986 one noted an inverse relationship between EMF and childhood leukemia, for example. On the other hand, it did find a correlation between EMF and childhood brain cancers while the later ones found none. The Oak Ridge panelists went on to find contrast after contrast. Epidemiologists generally believe conflicting positive results should be viewed as negative overall.
In the eyes of an epidemiologist, the inability of each of the other studies to confirm one specific connection lowers the possibility of that connection being real. Gerald Draper, the director of the Childhood Cancer Research Group at Oxford University, pointed this out in an editorial in the British Medical Journal. "The possibility that magnetic fields associated with electricity transmission may cause some cases of childhood cancer cannot be dismissed," he wrote, "but the lack of consistency among published studies, and the absence of an accepted biological explanation for such a relation, means that we have to conclude that at present no causal relation has been established."
It's impossible to know just how much EMF exposure a child received, so some system must be used to estimate it. The first study to link childhood leukemia and EMF from power lines was conducted in Denver by psychologist Nancy Wertheimer and her physicist friend, Ed Leeper. Unable to actually enter people's homes, they instead measured the distance between distribution lines and the homes themselves.
Using what they called wire code methodology, they and some of their successors, such as Dr. David Savitz of the University of North Carolina, found increased cancers with increased exposure. But Savitz, using spot measurements in the house, found that with this method there was no correlation between cancer and exposure. Dr. Stephanie London in Los Angeles added yet another method of measurement, hanging a detector around children's necks to measure their actual exposure. She found no correlation between actual exposures and EMF, nor between spot measurements and EMF, but did find a correlation using the Wertheimer-Leeper wire code. Similarly, Dr. Anders Ahlbom, chief researcher behind the Swedish studies, found that actual EMF measurements in homes, as opposed to his calculations of the exposure he thinks the individuals received over several years, correlate to a reduction in leukemia risk.
It may be that the coding system is truly best. It may be, as Savitz has suggested, that present-day spot measurements of EMF can't reflect fluctuations in fields that might have happened over time. But to say that London and Ahlbom have found an EMF-cancer correlation, as Brodeur and others have said, is to simply assume that the wire code is the best measurement tool.
No one knows if that's the case, however. This led Savitz, in his April 1993 overview of EMF studies in the American Industrial Hygiene Association Journal, to write "a number of inconsistencies and questions prevent a conclusion that magnetic fields cause cancer, including the failure of measured fields to be as strongly associated with cancer risk as are wire codes."
More recent studies in the October 1993 British Medical Journal, larger than the Swedish ones, also cast doubt on the EMF-cancer link. Just as the media ignored foreign studies prior to the Swedish ones and downplayed the negative associations in those studies, they likewise ignored these, from Sweden's neighbors, Finland and Denmark. Both were vastly larger than the Swedish one. The Danish one had 1,707 children with tumors and almost 5,000 controls, while the Finnish one followed essentially the entire child population of the country, over 150,000.
The Finnish study found no statistically significant correlation between EMF and all types of cancer combined or any individual cancer, except when it then broke the individual cancers down by gender, when it found a correlation to high EMF exposure and nervous system tumors in males. That correlation stood on the finding of three tumors in a single boy. By changing the analysis to per-patient instead of per-tumor, even that connection disappeared.
But What If?
Ironically, one of the solutions that occur to most people concerned about EMF--placing themselves further away from the source--could theoretically make things worse. That's because some of the studies finding positive EMF-cancer correlations indicate that low levels of exposure are worse than higher ones. This seems strange, because the usual rule of toxicity is the more exposure, the worse off you are. As one Carnegie-Mellon researcher, Indira Nair, explains, our conception of what causes cancer is based on our observation of chemical and ionizing radiation, such as that from X-rays or atom bombs, harm inducers. Assuming EMF are harmful, they would be inducing harm in a completely different way, by interfering with the timing of certain cell operations rather than by tearing apart molecules as carcinogenic chemicals do.
So when Paul Brodeur makes one of his television appearances with a gaussmeter (which measures EMF emissions) and urges viewers to get their own and avoid high-emission areas, even assuming his claims of the hazards of EMF are true, he would still be giving useless or even dangerous advice.
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Still, as Brodeur repeatedly states in Currents of Death, there are "32 published studies demonstrating ELF [extremely low frequency, another term for EMF] effects." What Brodeur doesn't say is that hundreds of studies have been performed in which EMF shows no biological effects. Further, "biological effects" aren't necessarily harmful. As the authors of a report on EMF for the Congressional Office of Technology Assessment noted, "A biological effect is not necessarily a significant health consequence."
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