Distribution and enrichment of radionuclides in the newly discovered high background area in Ullal on the southwest coast of India.

In order to understand the distribution of radionuclides in the newly discovered high background area in Ullal near Mangalore, soil and sand samples collected from different depths were analyzed for the concentration of primordial radionuclides by gamma spectrometry. The activity of 232Th and 238U in soil and sand was observed to be maximum in the 0-10 cm layer. The activity of primordial radionuclides was determined for the different size fractions of soil and sand to study the enrichment pattern. The highest activity was found in the 250-125 mu fraction in both soil and sand. The concentration of primordial radionuclides in riverine and marine sediments in the vicinity of the high background area was measured to understand the transportation of radionuclides in riverine and marine environments and to throw light on the formation of the new patches of monazite deposit. The results of these systematic investigations are discussed in this paper.