Elevated radon level in drinking water of Ajodhya Hill Area of West Bengal, India: probable health impact on lung and stomach.

A screening survey has been carried out to measure the radon concentration in drinking water at various locations of Ajodhya hill and surrounding areas in Purulia district of West Bengal, India, using AlphaGUARD radon monitor. The obtained Rn concentration in ground water varies from 5.71 ± 0.29 to 579.47 ± 23.18 Bq/l with an average of 110.00 ± 6.61 Bq/l. Comparison between our results with the internationally recommended reference levels reveals that drinking of water from the majority of these tube-wells can pose significant health risks to the local people. Correlation study indicates that tube-well depth has significant influence on the radon level in water samples. Using 60 l/yr and 1642.50 l/yr water consumption estimated annual effective radon doses for most of the samples (almost 70% and 96%, respectively) are high compared to the World Health Organization (WHO) and the European Union (EU) Commission prescribed reference dose limit of 100 μSv/yr. Also, the evaluated Excess Lifetime Cancer Risk (ELCR) values associated with the tube-wells are showing serious threat to the health of the locals.The primary goal of this work is to develop a radon profile map of this area and to find out the possible reasons behind the elevated radon level in ground water. This type of work may play a very crucial role to aware the locals in perspective of human exposure to radon. The local health officials and the water quality regulators of India are requested to take necessary steps for protecting the local people from water radon hazard.