United States Nuclear Regulatory Commission - Protecting People and the Environment

Sources of Radiation

Since the beginning of time, all living creatures have been, and are still being, exposed to radiation. Nonetheless, most people are not aware of all the natural and man-made sources of radiation in our environment.

A chart of the public's exposure to ionizing radiation (displayed below) shows that people generally receive a total annual dose of about 620 millirem. Of this total, natural sources of radiation account for about 50 percent, while man-made sources account for the remaining 50 percent.

Pie Chart Showing Sources of Radiation Exposure in the United States

For additional information, see the following topics:

Page Last Reviewed/Updated Friday, June 28, 2013