Low-level radiation exposure and its health effects

Complete text of publication follows. The low level exposure to alpha radiation emitted from radon and its progeny in general environment and the dwellings has received continuing attention as the radon has been found to be ubiquitous radioactive air pollutants to which all the organisms (e.g. bacteria, plants or animals including humans) are exposed everyday to varying amounts of ionizing radiation. These radiations are spontaneously emitted by naturally occurring radioactive material like 238U and 232Th, ever since their existence on earth. The exposure to alpha radiation emitted from radon poses health hazards not only to the workers at industrial units like thermal power plants, gas fired power plants, coal fields and oil fields but also to the dwellers in normal houses in their surroundings. Radon being an inert gas can easily disperse into the atmosphere immediately on its release. The solid alpha active decay products of radon like 218Po and 214Po become airborne and get themselves attached to the aerosols, dust particles and water droplets suspended in the atmosphere. When inhaled during breathe, these solid decay products along with air may get deposited in the tracho-bronchial and pulmonary region of lungs resulting in the continuous irradiation of the cells which may be the cause of lung cancer. In the present work, we report on the estimation of the radon concentration, annual exposure and annual effective doses received by the workers working in the interior environment of some industrial units like thermal power plants and different types of dwellings of North India. For these measurements we have used the alpha sensitive solid-state nuclear track detector (SSNTD). The results indicate an increase in radiation dose received by the workers in thermal power plants due combustion of coal as compared with normal dwellings.