Measurement of thoron and radon progeny in outdoors of Sirsa (India), using defined solid angle absolute beta counting

Defined solid angle absolute beta counting technique is used to measure the equilibrium equivalent concentration (EEC) of radon and thoron from the filtered aerosol samples collected at Sirsa (India), in the months of September-October 2009. The value of 220Rn EEC determined during the same measurements varies from 0.98 to 3.27, minimum for afternoon and maximum for morning. An effective equivalent dose outdoor of 0.023 mSv y-1 due to the average EEC Th of 1.65 Bq m-3 was calculated with a conversion factor of 10 nSv Bq-1 h-1 m-3 and an occupancy factor of 0.2. For EEC Rn with an average value of 13.02 Bq m-3, the effective equivalent dose calculated using the conversion factor of 9 nSv Bq-1 h-1 m3 and the occupancy factor of 0.2 was 0.164 mSv y-1. The world average inhalation effective dose due to radon and its progeny is 1.2 mSv y-1 as recommended by UNSCEAR, which reveals that the studied area is safe from health hazards. (authors)