Radon concentration and potential risks assessment through hot springs water consumption in the Gilgit and Chitral, Northern Pakistan

This study investigated the concentration of radon (222Rn) in hot springs water. For this purpose, 222Rn concentration was measured using the RAD7 (Durridge Company, USA) in the water of hot springs located in Tata Pani, Gilgit (n = 4), and Garam Chashma, Chitral (n = 6), northern Pakistan. Water samples from the springs (background, n = 3) were also collected and analyzed for 222Rn concentration 40-50 km away from the hot springs in Gilgit and Chitral, northern Pakistan, to be used as background/reference concentration. The determined 222Rn in hot springs water surpassed the threshold of maximum contamination level (MCL, 11.1 Bq/L) set by the United States Environmental Protection Agency (US-EPA) in 100% samples collected from Tata Pani, Gilgit, and Garam Chashma, Chitral sites. Soil 222Rn along with the hot springs exhibited a decreasing trend with increasing distance. 222Rn concentration in hot springs water was used to calculate the exposure doses of human health through ingestion and inhalation pathways. The total effective dose for human (EWT) of 222Rn contaminated water consumption was 626 mu Sv/a in the Tata Pani, Gilgit and 34.7 mu Sv/a in the Garam Chashma, Chitral. Results revealed that hot springs water in the Tata Pani, Gilgit had surpassed the threshold limit (100 mu Sv/a) set by the World Health Organization (WHO). This study concluded that hot springs water should be avoided for drinking and other domestic uses.