Natural Radioactivity (Radon-222) and Air Pollution Measurements in Washington, D. C.

Abstract

Atmospheric concentrations of radon (Rn222) were measured at urban, suburban and rural sites in the Washington, D.C., metropolitan area during a stagnant weather regime in mid August 1965. An analysis of air quality data, radon concentrations and meteorology indicates that the stagnant weather conditions which lead to the accumulation of smoke, haze and gaseous pollutants in the air, are conducive to the accumulation of radon in the lower atmosphere. During maximum stagnation radon concentrations were 2?4 times higher than normal; the high levels of natural radioactivity reflect the limited volume of air available for dilution, caused by a restriction to vertical mixing that prevailed throughout the stagnant period. This case study suggests that high concentrations of natural radioactivity will be indicative of air pollution potential conditions existing in the atmosphere. Also, air quality data indicated that heavy rains and vigorous mixing associated with a squall line were ineffective in cleansing or displacing, for a significant length of time, the polluted air mass.