Baseline assessment of doses and risk due to natural radionuclides in edible biota of Domiasiat, Meghalaya, India

Abstract

Radiation dose-risk assessment was carried out for cereal species Brassica compestris var. dichotoma, Oryza sativa var. Shalum1, Zea mays, Lactuca indica, Cumunis sativum, and Clocasia esculanta due to naturally available radionuclides 40 K, 238 U and 232 Th in Domiasiat area. The activity in biota and corresponding soil was measured by precipitation method using NaI(TI) detector. Transfer factor (TF) was for Oryza spp. (1.00E-01-40 K, 8.76E-05-232 Th, and 9.11E-05-238 U), for Brassica spp. (5.39E-01-40 K, 8.17E-04-232 Th and 2.96E-04-238 U) and for Zea spp. (3.41E-01-40 K, 5.84E-05-232 Th, 8.87E-05-238 U) etc., respectively. A detailed physio-morphological study of the biota and extensive investigation of ecosystem was carried out for assessment. The data was modeled using FASSET for dose estimation and obtained total dose was 1.58E-04 lGy h À1 in Oryza spp., 2.87E-04 lGy h À1 Brassica spp. and 6.90E-03 lGy h À1 in Zea spp. etc. The dose was compared with the UNSCEAR dataset for screening level dose for biota. Zea spp. was more susceptible for the chronic radiation exposure.