Estimation of alpha radioactivity in some soil samples collected from eastern Haryana

All humans are constantly exposed to radiations spontaneously emitted by naturally occurring atomic elements ever since their existence on the earth. Radon ( 222 Rn) has been identified as the largest single source of radiation exposure to world population. Indoor radon has been recognized as one of the health hazards for mankind. Common building materials used for construction of houses are considered as major sources of radon gas in indoor environment. In the present work, the radon exhalation rates were measured using 'Canister' technique. The alpha sensitive solid state nuclear track detector (LR-115 type-II) were used in the canisters for recording tracks produced by alpha particles from radon gas emanated from soil samples. The soil samples were collected from Sonipat ,Panipat and Karnal districts of eastern Haryana, India. The detectors were exposed in the canisters for 100 days. After the exposure, the detectors were etched using 2.5 N NaOH solution at 60˚ C for 1.5 hours. The track density was found using an optical microscope at a magnification 600X. The mass and surface exhalation rates are also calculated from the data. . The measurements indicate normal to some higher levels of natural radioactivity in soil samples. However, these samples satisfy the universal standards (UNSCEAR, 2000) limiting the radioactivity within the safe limits.