Assessment of gross alpha, gross beta, 210Po, and 210Pb in rice and their associated health risks in Tamil Nadu, India: A baseline study.

Abstract

The natural radioactivity content of rice is a critical factor in assessing the public's exposure to natural radionuclides through dietary intake. This study investigated the activity concentrations of gross alpha, gross beta, 210Po, and 210Pb in 37 varieties of rice collected from commercial mills in Kalambhur, Arni, Thiruvannamalai district, Tamil Nadu, India. These mills supply rice to major department stores and ration shops throughout Tamil Nadu. Gross alpha and gross beta activity concentrations in the rice samples ranged from below the detection limit (BDL) to 27.59 ± 2.78 Bq/kg and BDL to 61.31 ± 6.23 Bq/kg, respectively. Similarly, 210Po activity concentrations ranged from 1.03 ± 0.42 to 14.35 ± 1.76 Bq/kg, while 210Pb activity concentrations were between 6.28 ± 0.72 and 37.41 ± 3.11 Bq/kg. A risk assessment was conducted to evaluate the excess lifetime cancer risk (ELCR) and committed effective dose equivalent (CEDE). The average CEDE was below the global average reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The average daily intake of 210Po and 210Pb from rice consumption was estimated to be 1.39 Bq/day and 5.60 Bq/day, respectively. Notably, 210Pb activity was higher than 210Po, gross alpha, and gross beta. The average mortality and morbidity risks associated with 210Po intake through rice were 1.58 × 10-3 and 2.17 × 10-3, respectively. For 210Pb, the corresponding risks were 3.31 × 10-3 and 4.55 × 10-3. All measured values fell within acceptable limits, indicating no significant radiological health risks associated with consuming rice from the study area. This study provides a baseline assessment of radionuclides in rice and related ingestion doses in Tamil Nadu, contributing valuable data for radiological monitoring and public health.