Radioactivity associated with common salt and estimation of ingestion dose to the general public

摘要

The sea brine and sub-soil brine used for the manufacture of common salt contain several chemical and radioactive elements. This study estimated the gross alpha and gross beta activities from the sea and sub-soil brine at two salt works at Kovalam and Puthalam in Kanyakumari District, Tamil Nadu. The activity of the sea brine was higher than that of the sub-soil brine. The gross activity was increasing at subsequent stages of production due to the concentration of brine. The sediments and gypsum samples collected at different stages were also subjected for estimation of different types of activity. super(40)K activity was found to increase, source to bittern, from 8.6 to 162.16 Bq l super(-1) at Kovalam and 8.59 to 198.98 Bq l super(-1) at Puthalam. The ingestion dose due to consumption of salt was calculated to be 13.61 mu Sv per year, the highest contribution (12.42 mu Sv) coming from super(226+228)Ra. This study shows the influence of natural high-background radiation areas on the radioactivity in common salt and calls for setting limits for radioactivity contents in it.