Nonionizing Radiation Levels in the Washington, D.C., Area

In order to determine the typical levels of radio frequency and microwave radiation that result from man-made sources in an urban environment, measurements were made of peak power densities in the Washington, D.C., area during the summer of 1969. Radiation levels were monitored over the frequency range from 20 Hz to 10 GHz at ten sites within a 25 mile radius of the city. Experimental accuracy can be estimated at ±10 dB. The highest levels measured (approximately 10-2 mW/cm2) originated primarily from AM broadcast towers and airport radar installations. These values fall 30 dB below any published U.S. recommendations for occupational exposure.