Besides cell phones, what are other sources of RF energy?

The most common use of RF energy is for telecommunications. In the United States, cellular telephones operate in a frequency range of about 1,800 to 2,200 megahertz (MHz). In this range, the electromagnetic radiation produced is in the form of non-ionizing RF energy. AM/FM radios, VHF/UHF televisions, and cordless telephones (telephones that have a base unit connected to the telephone wiring in a house) operate at lower radio frequencies than cellular telephones. Other sources of RF energy, including radar, satellite stations, magnetic resonance imaging (MRI) devices, industrial equipment, and microwave ovens, operate at somewhat higher radio frequencies.

This answer is based on source information from the National Cancer Institute.