NATURALLY OCCURRING RADIONUCLIDE 40K BODY CONTENT OF KAKRAPAR GUJARAT SITE POPULATION

An attempt was made to investigate the naturally occurring radionuclide 40K body content of the Kakrapar Gujarat Site (India) population by using whole-body counting method. The population comprises occupational workers (regular and contract personnel working at Kakrapar Atomic Power station) and students from various educational institutions. A total of 1056 subjects of different age groups and gender were monitored for 40K body content by using a Standfast-II Whole Body Counting System. The reactor released radionuclides such as 137Cs, 60Co and 131I are not detected in occupational workers of Kakrapar Atomic Power station which indicates that occupational workers are free from radioactive contamination. Based on the activity measurement, an effective dose due to 40K was estimated for different groups of the site population based on the dietary habits, sex and age. Statistical significant correlation was not observed in any of the groups. The annual effective dose due to 40K was found to be in the range of 52–243 μSv y−1 with an average of 133 ± 35 μSv y−1 for the vegetarian group (588 subjects), 60–223 μSv y−1 with an average of 136 ± 35 μSv y−1 for the non-vegetarian group (468 subjects), 52–243 μSv y−1 with an average of 134 ± 35 μSv y−1 for the male group (1007 subjects) and 67–203 μSv y−1 with an average of 128 ± 35 μSv y−1 for the female group (49 subjects), respectively. Among the four age groups of the population studied, an effective dose due to 40K is slightly higher in the age group of 20–29 (161 subjects). The annual effective dose due to 40K reported by UNSCEAR, 1982(3) is 180 μSv y−1.