Some scientists believe that the effect EMFs have on melatonin production explains many otherwise unaccountable physiological maladies, but the links are far from conclusive. At sufficiently high power levels, EMFs can cause body heating, which, with long-term exposure, may result in health hazards such as blindness or sterility. Most ordinary household appliances and transmitted radio signals produce EMFs far weaker than those required to produce thermal effects. Epidemiological studies also show negative health effects at certain frequencies but not at adjacent frequencies. All of these studies do not present conclusive evidence linking certain types of EMFs to increased health risks.
Research continues in order to establish the true extent of the threat to human health.
At least 27 countries support EMF research, including Canada, Denmark, Italy, Japan, Norway, Russia, Sweden, the United Kingdom, and the United States. Although it is difficult to perform identical experiments, steps are being taken by the scientific community to synchronize the experiments worldwide, standardize experimental methodologies, and validate results and conclusions. At present, there is no federally mandated RF exposure limit in the United States. However, U.S. Government, commercial, and international organizations have taken action and EMF research is under way. In the United States, the Federal Government has conducted public EMF studies for at least 20 years.