VARIATION IN CANCER RISK ESTIMATES FOR EXPOSURE TO POWERLINE FREQUENCY ELECTROMAGNETIC-FIELDS - A METAANALYSIS COMPARING EMF-MEASUREMENT METHODS

We used meta-analysis to synthesize the findings from eleven case-cont rol studies on cancer risks in humans exposed to 50-60 Hertz powerline electromagnetic fields (EMFs). Pooled estimates of risk are derived f or different EMF measurement methods and types of cancer. EMF measurem ent methods are classified as: wiring configuration codes, distance to power distribution equipment, spot measurements of magnetic fields, a nd calculated indices based on distance to power distribution equipmen t and historic load data. Pooled odds ratios depicting the risk of can cer by each measurement type are presented for all cancers combined, l eukemia for all age groups and childhood leukemia. The wire code measu rement technique was associated with a significantly increased risk fo r all three cancer types, while spot measures consistently showed non- significant odds ratios. Distance measures and the calculated indices produced risk estimates which were significant only for leukemia.