Seasonal Assessment of Radon, Thoron and their Progeny levels in the Dwellings near the Fly Ash Dumping Site situated in Faridabad (Haryana), India

In order to meet the growing demand for of electricity, coal - based thermal power plants are widely used all over the world. These thermal power plants produce a huge amount of fly ash as a by- product of coal combustion. The disposal and management of this ash become a challenging problem for the environmentalist and sci entist. Coal ash contains an enhanced level of radionuclides along with some other elements, that are toxic and it a e ffect the surrounding environment of the dumping site. So, health and hygiene consciousness promote the present study of dwellings near the fly ash dumping site situated in Faridabad, Haryana, India. Twin cup dosimeters were used for the measurements during the four seasons of a year. Measurements show that the minimum and maximum value of radon and thoron concentration varies from 6.70 ±0.31 Bqm -3 during summer to 139.79±2.93 Bqm -3 during winter, 1.36±0.12 Bqm -3 during summer to 78.37±2.16 Bqm -3 during winter s respectively. The PAEC due to radon and thoron, annual exposure due to radon and thoron collectively var y ies from 0.72±0.03 mWL during summer to 15.11±0.32 mWL during winter , 55.66×10 -3 WLM to 642.25×10 -3 WLM respectively .  Annual effective varies from 0.21 mSv to 2.46 mSv . The measurements indicate that the radon concentration was below the safety levels (action levels) as recommended by various regulatory bodies. The maximum value of 139.79±6.55 Bqm - 3 was found inside the cave of a temple, where there was no ventilation. The different values of radon concentrations are due to different ventilation conditions, house structures and the distance of dwellings from the dumping site. The radon concentration was found to decrease with the increase in distance of the dwelling from the fly ash dumping site. Keywords: Radon, Thoron, Fly ash, dDumping site, dwellings,. fly ash, Radon, thoron