DISTRIBUTION OF SOME NATURAL AND ARTIFICIAL RADIONUCLIDES IN MANGALORE ENVIRONMENT OF SOUTH-INDIA

The activities of K-40, Ra-226, Ra-228, Po-210, Pb-210, Cs-137 and Sr- 90 were determined in a number of natural samples in the environment o f Mangalore, South India where lar ge-scale industrial activities are envisaged. Well-established nuclear techniques were employed to measur e the activities and wherever necessary radiochemical methods were als o followed. The measurement of transfer coefficients indicated that th e uptake of Ra-226, Rn-228 and Pb-210 in paddy is higher than that in vegetables. The measured activity ratios of Po-210: Pb-210 and Ra-228 :Ra-226 in soil samples suggest the existence of equilibrium between t he corresponding radionuclides in normal background areas and disequil ibrium in high background areas. The intake of radionuclides by the po pulation and the internal dose were estimated. The annual internal eff ective dose for the population is found to be 341 mu S nu year(-1) whi ch mainly arises from K-40 and Pb-210.