February 20, 2006
Electromagnetic Fields and Cancer: Shocking Junk Science
By Michael D. Shaw
Few things are more resilient than urban legends. For some reason, people really want to hold certain beliefs, no matter how illogical or unlikely they may be. A popular cable TV show, “Mythbusters,” uses the talents of FX wizards to test pop myths, and most are busted. Still, this has not damped the public’s enthusiasm for contemporary folklore, especially when they need to find a reason for bad events in their lives. Case in point: The persistent belief that power lines and other sources of electromagnetic fields are responsible for huge increases in cancer among people in surrounding areas.
The idea that power lines cause cancer can be traced back to a 1979 article in the American Journal of Epidemiology entitled “Electrical Wiring Configurations and Childhood Cancer.” This work, performed by Nancy Wertheimer and Ed Leeper, implied that the incidence of childhood leukemia was higher in Denver neighborhoods that were near electric power lines. Their report caused a real panic at the time, inspiring Paul Brodeur of the New Yorker to write a frightening three-part article that reached a large and influential audience.
Subsequent books by Brodeur in 1989 and 1993 alleged that power lines were “Currents of Death” and that the power industry and the government were engaged in a cover-up. The list of conditions purportedly related to electromagnetic fields now includes Alzheimer’s disease, Lou Gehrig’s disease, brain tumors, and breast cancer, and multiple chemical sensitivity.
As it turns out, this was all junk science. It took other researchers to do what should have been the job of the editorial board of the original journal. There were three major flaws in the study:
1. Magnetic fields were never measured. Thus, the very causal agent being indicted was only inferred by the wiring codes of the homes involved. In fact, later studies did measure the fields and found no correlation with incidence of cancer. Whoops!
2. Wertheimer and Leeper also failed to correct for the rather obvious confounding factor of income. Homes located close to power line towers are not considered desirable, and their study was biased toward poorer people. Sadly, there IS a correlation between poverty and cancer, and it goes far beyond proximity to power lines.
3. The study size was small, further skewing the statistics. Indeed, a study published in 1993, covering a cohort of 134,800 children, with one million person-years of exposure discerned 140 cancers in the group, five fewer than would be expected by chance.
If the original study had any merit at all, subsequent research would confirm—at least qualitatively—the findings. Not only was that not the case, but in 1997, the National Cancer Institute produced a huge study, published in the prestigious New England Journal of Medicine that found no association between childhood leukemia, and either wiring codes or measured magnetic fields. The same issue of the Journal included an editorial calling for an end to wasting money on electromagnetic field/cancer research.
According to famed physicist J.D. Jackson, during the last few decades the use of electric power and electric appliances has increased the 60 Hz power line magnetic fields to which people in this country are exposed by roughly a factor of twenty. If power line fields were a significant cause of leukemia, there should have been a dramatic rise in leukemia. Leukemia rates, however, have slowly decreased. Yet another nail in the coffin of this nonsense.
Additional factors perpetuating this myth involve those who keep making money on studies, or those who have staked their reputation on this blather. There’s also fraud. In June 1999, the NIH Office of Research Integrity announced that Robert P. Liburdy, Ph.D., a former staff biochemist at Lawrence Berkeley National Laboratory, had engaged in scientific misconduct by intentionally falsifying and fabricating data and claims about purported cellular effects of electromagnetic fields reported in two scientific papers.
As long as greedy charlatans can find hapless victims, and the public is shockingly clueless on all things scientific, this and many other health urban myths will continue. Why take charge of your own life, when it’s easier to blame someone or something else?