Long-term monitoring of radioactivity in surface air and deposition in New York State.

摘要

Gross-beta activities have been determined weekly for 22 y from filtered atmospheric aerosols at seven sites in New York State. The activities, ranging from 0.1 to 0.9 mBq m(-3), varied seasonally and were evaluated in terms of meteorological factors. Cosmogenic beryllium (7Be) concentrations were determined quarterly on the air filters and weekly in deposition collected at one site. Over 98% of the air filters contained observable activity concentrations of 7Be (mean of 3 mBq m(-3)) and 210Pb (mean of 1 mBq m(-3)). However, only 20% of deposition samples contained Be concentrations above analytical detection limits. Tritium (3H) concentrations were below detection limits in deposition samples at the background site, but were present on most samples collected near a H-processing facility. Measurements of 131I were conducted weekly on charcoal canisters, with only one site showing observable concentrations (mean of 1 mBq m(-3)), due to nearby incineration of dried municipal sludge containing patient waste from hospital treatments.