Abstract
Be-7 is a cosmogenic radionuclide with a half-life of 53.3 d produced mostly in the stratosphere by cosmic ray spallation of nitrogen and oxygen and entering the lower troposphere by atmospheric circulation processes. Be-7 emits gamma rays of energy 477.6 keV and its concentration in the ambient air can be measured by gamma spectrometry. In the present study, the activity concentration of Be-7 in outdoor ambient air of Lahore city, Pakistan, has been measured employing two air samplers and using a high purity germanium [HP(Ge)] detector. The Be-7 activity concentration was found in the range from 1.6 to 11.3 mBq m(-3) with a mean value of 5.4 mBq m(-3).