Annual Effective Dose and Excess Lifetime Cancer Risk Associated with Radon Exposure in Tap Water of Chiang Khan District, Loei Province, Thailand

Abstract

Objectives of this study were to determine radon concentration in tap water and assess the annual effective dose (AED) and excess lifetime cancer risk (ELCR) associated with radon exposure in tap water in Chiang Khan District, Loei Province, Thailand. A total of 40 water samples were collected to determine radon concentration using the RAD7 radon detector and analyze the physical and chemical properties of the water using a multiparameter water quality meter. The results showed that radon concentrations in tap water were between 0.007 and 1.973 Bq/L with an average of 0.099 ± 0.307 Bq/L. The highest concentration was observed at one sampling location (1.973 Bq/L), although all measured values remained considerably below the World Health Organization (WHO) and U.S. Environmental Protection Agency (USEPA) recommended limits of radon levels in tap water. Radon concentration has a negative correlation with temperature. The AED and ELCR assessments showed that the infant group (0-1 years) had the highest risk compared to the children and adult groups due to the higher rate of water consumption per body mass. However, AED and ELCR values for all age groups were still low and did not exceed the levels that pose radiation risks to public health. This study provides the first baseline data on radon levels, associated radiological risks, and water quality parameters in tap water from Chiang Khan District, Loei Province.