Annual dose for different age groups due to natural radioactivity in drinking water in the surroundings of coal mines

Exposure to radionuclides through ingestion of water has adverse effects on the miners and population in the nearby surrounding areas. Coal mines water collected directly from the coal mines of Dukki and drinking water collected from wells in the surroundings of the coal mines were tested for radioactivity and associated health effects using a High Purity Germanium (HPGe) detector. The average values of 226Ra in coal mines water and well drinking water were found to be 6.05 ± 1.75 and 9.87 ± 3.27 mBq L−1, respectively. The average values of 232Th in coal mines water and well drinking water were found to be 3.84 ± 1.68 and 13.27 ± 3.10 mBq L−1, respectively. The average values of 40K in coal mines water and well drinking water were found to be 202.28 ± 6.41 and 221.67 ± 6.13 mBq L−1, respectively. The average values of all radionuclides in both coal mines water and drinking water were found to be less than the recommended safe values of the World Health Organization (WHO). A positive correlation (r2 = 0.899) between 222Rn and 226Ra was obtained, which suggests the presence of 222Rn in water due to 226Ra content in water. Negative correlations among pH and different radionuclides suggest a decrease in radionuclides with the increase of pH. The annual effective doses due to 222Rn,226Ra, 40K and 232Th for different age groups were found to be less than the recommended safe values of WHO. Box plot analysis shows a symmetrical distribution of radioactive elements in coal mines water and drinking water. It is clear from the results that the coal mines water and drinking water of Dukki, Balochistan, have no significant radiological risk was identified based on the investigated radionuclides and current dose assessment.