The first evidence that I can recall that prompted Dr. Becker to suspect that powerline EMFs could affect human health was the information that he received at a blue-ribbon committee meeting in December, 1973 in Washington, DC. Prior to that time I do not think he realized the potential problem, nor the relationship of the research then being performed in our laboratory to that problem. Dr. Becker reasoned that if environmental EMFs were a health risk, then there ought to be evidence of such an impact among the general population. He therefore conducted an epidemiological study aimed at directly assessing this question. See R.O. Becker: Microwave radiation, New York State J. Med. 77:2172, 1977. Dr. Becker's report was the first to link environmental EMFs with cancer. Some months earlier, Milton Zaret published a report in the same journal that linked occupational exposure to EMFs and cancer. See M. Zaret, Potential hazards of Hertzian radiation and tumors, New York State J. Med. 77:146, 1977.
The process whereby scientific reasoning regarding potential health risks begins with animal studies and then seeks confirmation in epidemiologic studies simply seemed natural to Dr. Becker. But as the EMF dispute grew, the relative importance of epidemiological and laboratory data itself became a contentious issue. Some epidemiologists argued that EMFs don't affect human health because the epidemiological studies were equivocal or otherwise not reliable. The gist of their argument seemed to be that highly reliable epidemiological studies were possible, and were needed to sustain a conclusion that powerline EMFs affect human health.