Today it is a rare thing to see a kitchen that is without a microwave oven. In the mid 1970 s extensive research was undertaken as to the potential risks involved in exposure to low level microwave radiation. As a result, in the United States the allowable level of leakage of a microwave oven was set at 1,000 microwatts per square centimetre at a distance of five centimeters and 5,000 microwatts per square centimeter thereafter. The only way to know if your microwave oven is leaking radiation within these specified levels is to have it checked by an authorised serviceman. There is still debate, however, as to whether the allowable levels of leakage are really safe.
Some scientists believe that microwave radiation has a cumulative effect on the body.
In other words a low level dose of radiation the first day which in and of itself is not harmful can combine with similar low levels on subsequent days to build up to a dangerous level. It would pay then to follow some simple safety rules when using your microwave oven. A door with cracked or faulty latches should not be used. Do not use scouring pads or steel wool. Never look into an operating oven.