Distribution of some natural and artificial radionuclides in Mangalore environment of South India

The activities of 40K, 226Ra, 228Ra, 210Po, 210Pb, 137Cs and 90Sr were determined in a number of natural samples in the environment of Mangalore, South India where large-scale industrial activities are envisaged. Well-established nuclear techniques were employed to measure the activities and wherever necessary radiochemical methods were also followed. The measurement of transfer coefficients indicated that the uptake of 226Ra, 228Ra and 210Pb in paddy is higher than that in vegetables. The measured activity ratios of 210Po: 210Pb and 228Ra:226Ra in soil samples suggest the existence of equilibrium between the corresponding radionuclides in normal background areas and disequilibrium in high background areas. The intake of radionuclides by the population and the internal dose were estimated. The annual internal effective dose for the population is found to be 341 μSv year−1 which mainly arises from 40K and 210Pb.