The natural radioactivity in drinking water by gross alpha and beta measurements and radiological quality assessment

Abstract

The aim of this study is to investigate the radiological quality of drinking waters consumed in Nevşehir province which is the most important tourism destination of the Cappadocia region. The activity concentration of gross α- and β-emitting from natural radionuclides (238U, 234U, 230Th, 226Ra, 210Po, 232Th and 210Pb, 228Ra and 40K) in 21 tap water samples supplied by municipal pipelines were analyzed by using a gas proportional α/β counter. The average activity concentrations of the gross α and gross β in tap water samples were found as 88 ± 10 mBq L-1 and 305 ± 32 mBq L-1, respectively. The average natural activity concentrations of α- and β-emitting radionuclides in tap water samples are below the limit values recommended by the Turkish regulation and WHO. For all samples, except for one sample, the gross β activity concentrations are higher than the corresponding gross α concentrations. The average annual effective radiation dose (AERD) due to the ingestion of these water samples was estimated to be 43, 60 and 124 μSv year-1 for infants, children, and adults, respectively. The average of AERD estimated for adults is 24 % higher than the dose limit of 100 μSv year-1. The activity concentration results reveal that tap water samples are acceptable for human consumption in accordance with the Turkish regulation and WHO recommendations for drinking water.