Transfer Factors and Effective Dose Evaluation Due to Natural Radioactivity in Staple Food Grains from the Vicinity of Proposed Nuclear Power Plant

Abstract

This study focused on quantification of radioactivity concentration of naturally occurring radioactive materials 40K, 226Ra and 232Th in most staple food grain i.e. wheat of the study area using gamma spectrometry for two years. 40K, 226Ra and 232Th activities were detectable in most of the wheat grain samples and ranged 111.3–245.7, 226Ra (41 ± 1.6 Bq kg−1) > 232Th (32.3 ± 1.2 Bq kg−1) and comparable to the corresponding levels obtained worldwide. The geometric mean transfer factors of studied NORMs in wheat grains were in order: 40K (0.371 ± 0.07) > 226Ra (0.003 ± 0.002) > 232Th (0.001 ± 0.001). Significant positive dependencies of transfer factors of 40K, 226Ra and 232Th in wheat grains were observed with total organic carbon content of soil. Estimated annual effective doses from ingestion of the wheat were 1.37E−01 mSv year−1 for 40K, 4.14E−03 mSv year−1 for Ra226 and 1.10E−03 mSv year−1 for 232Th, well under the permissible cumulative global average.