Within the home, electrical equipment and elements of the household electrical system may contribute to magnetic field exposures. In our study, appliances contributed only a small amount to the children's measured exposure. It is important to remember that EMFs diminish rapidly as you move away from the source. Therefore, appliances that are used close to the body and for prolonged periods of time are more likely to contribute significantly to a person's exposure. Examples of these are hair dryers, can openers and other electrical equipment with a motor.
Wire code is a way of categorizing homes according to magnetic field levels.
It does not involve measuring the fields, but rather considers the size, number and type of electrical conductors outside the home and their distances from the home. Because electrical distribution systems vary by jurisdiction, so can wire codes. The magnetic field levels in a given wire code category can vary from one jurisdiction to another. The most common differences between studies relate to how the exposures were measured, how the subjects were selected, how other factors which might also be related to leukemia were taken into account and how the data are analyzed. These included the child's medical history, reproductive history of the mother, exposures to pesticides, chemicals, x-rays, and medications taken by the mother during pregnancy.