Epidemiological principles for EMF and EMR studies

Abstract

Epidemiology is fundamental science and the strongest evidence for the assessment of human health effects of disease agents. Moving from a possible association to a causal effect the assessment principles are followed by the Sir Austin Bradford-Hill approach. When dealing with the health effects of electromagnetic fields and radiation some specific and important epidemiological principles must be used. Exposure assessments are vital. Electromagnetic fields and radiation are invisible, odourless, silent and tasteless, and are ubiquitous. Therefore the basic physics and engineering principles that explain the nature and strength of these fields are fundamental. The basic methods of environmental epidemiology involve identifying the disease rates in an exposed group to compare the disease rates in a non-exposed group, with no confounders to confuse the results. A major problem with EMF and EMR is that in most communities there is no non-exposed reference group because we live in homes with electromagnetic fields from electric power wires and appliances and we can receive radio, TV and cellphone signals all the times in our homes. Everyone in the world is exposed to radio short-waves and satellite microwaves. This has led to the Ubiquitous Exposure (No Non-exposed Group) Principle, an extension of the Healthy Worker Effect. For studies around Radio, TV and cell site transmission towers, the horizontal antenna patterns are used to focus most of the RF energy into beams to send them to where most of the receiving population lives. The vertical antenna patterns are a function of the frequency of the carrier signal. They have main beams and many side-lobes which produces complex radial undulating signal intensity varying with distance from the tower. For studies of people living in the vicinity of radio, TV and cellphone towers it is vital that the radiation patterns and population patterns are understood. Studies that appropriately match exposure with cancer and other health effects, show strong, consistent and significant doseresponse relationships indicating causal linkage between electromagnetic fields and radiation and human health effects.