Microwave radiation may cause cancer and disrupt immune systems, and its magnetic fields create long-term nervous disorders.
Microwave cookers operate at higher frequencies than most domestic appliances, but are shielded.
Microwave radiation is emitted by military and civilian radar installations, satellite ground stations, relay towers for long-distance telephone links and television transmitters, as well as microwave ovens and citizens band radios. Results emerging from a USA study in 1984, investigating the biological and health effects of non-ionizing radiation, show glandular changes and a higher rate of cancer among laboratory rats chronically exposed to low-intensity microwaves. These findings could provide an experimental basis for widely reported complaints of headaches, dizziness, memory loss and fatigue from people chronically exposed to microwave radiation.
Research reported in 1995 showed that cooking or heating food in microwave ovens can cause it severe molecular damage which, when eaten, leads to abnormal changes in human blood. These changes can cause deterioration of the immune system. In 1991, an extension service of the University of Minnesota warned against heating babies' milk bottles in microwaves for both practical safety and nutritional reasons: Heating the bottle in a microwave can cause slight changes in the milk. In infant formulas there may be a loss of some vitamins. In expressed breast milk some protective properties may be destroyed.
Smartphones impart similar energy to that of microwaves. In New Zealand and Australia it is forbidden to erect mobile telephone transmitting masts on school properties. In California communications companies are advised not to install equipment near educational properties.