Evaluation of the Excess Lifetime Cancer Risk Due to Natural Radioactivity in Tap Water Consumed in Nevşehir Province, Turkey

Ionizing radiations (alpha-, beta- and gamma-rays) emitted from radionuclides in waters can produce detrimental biological effects for human health. The excess lifetime cancer risk relates to the probability of developing cancer over a lifetime at a given annual exposure dose rate. Nevşehir province, which is one of the most important cultural and religious tourism centers in the world because of it’s the unique geology, history and culture, is located in the Cappadocia region in Central Anatolia of Turkey. Underground water resources are used as drinking water in Nevşehir. Tap water used in homes, workplaces, hotels, schools etc. are supplied from wells drilled by the municipality. In this study, the excess lifetime cancer risk was evaluated for adult living in Nevşehir province based on the contents of gross alpha and gross beta in tap water samples collected from various districts in Nevşehir. The values of the excess lifetime cancer risk varied 1.7 x 10 -4 to 1.3 x 10 -3 with an average of 5.5 x 10 -4 . Consequently, the excess life time cancer risks values via tap water consumption were found below the acceptable limit of 10 -3 for radiological risk.