Q: I am planning to build a house at a place, which is located about 200 feet from a high tension (high voltage) overhead electricity line. Are there any serious hazards of EMF emitted from high tension wires & what is a safe distance to build a house near high tension wires?

A:One ironic fact about low-frequency electromagnetic fields is that we live and worry about them within the Earth's static magnetic field of 50 µT, which is hundreds of times greater than the oscillating magnetic field produced by 110/220-V current in houses (0.01 to 0.05 µT).Even directly under high-voltage transmission lines, the magnetic field is only about 3 to 10 µT, which is less than that in an electric railway car and much weaker than the magnetic field close to the head when an electric razor is used (about 60 µT). Although most physicists find it inconceivable that power-line electromagnetic fields could pose a hazard to health, dozens of epidemiologic studies have reported weak positive associations between proximity to high-voltage power lines and the risk of cancer. The negative or equivocal studies did not end the controversy. Fear of leukemia is a powerful force, and the media response amplified the perception of electromagnetic fields as a health hazard. In 1989 The New Yorker published three articles by journalist Paul Brodeur that described in mesmerizing detail how maverick researchers had discovered a cause of cancer that the establishment refused to accept. Like many of the epidemiologic studies themselves, these widely quoted articles described biologic mechanisms of action for electromagnetic fields that were hypothetical, even fanciful. Brodeur went so far as to claim that the search for the truth about the hazards of electromagnetic fields was threatened most by the obfuscation of industry, the mendacity of the military, and the corruption of ethics that industrial and military money could purchase from various members of the medical and scientific community. Suspicion spread to many other wavelengths on the nonionizing electromagnetic spectrum, producing fears about occupational exposure to electricity as well as exposure to microwave appliances, radar, video-display terminals, and even cellular telephones. Dozens of studies looked for associations with brain cancer, miscarriages, fetal-growth retardation, lymphoma, breast cancer, breast cancer in men, lung cancer, all cancers, immunologic abnormalities, and even changes in the behaviour of animals. In recent years, several commissions and expert panels have concluded that there is no convincing evidence that high-voltage power lines are a health hazard or a cause of cancer.