Investigation on gross radioactivity levels in paddy, vegetables and cultivated soil in Guangdong Province

This study investigated the gross radioactive background levels in paddy, vegetables, and cultivated soils around major agricultural production bases and key nuclear and radiation facilities in Guangdong Province. From 2018 to 2022, continuous sampling and follow-up monitoring were conducted on paddy, vegetables, and their respective soils. The collected data were statistically analyzed by area and city to explore the α/β ratio in soils across different locations. The gross α, gross β and 40K specific activities in paddy are (13.8±11.5) Bq/kg, (105±13) Bq/kg, (114±16) Bq/kg, respectively. The gross α, gross β and 40K specific activities in vegetables are (4.7±4.9) Bq/kg, (93±33) Bq/kg, (109±47) Bq/kg, respectively. The gross α specific activities of paddy soil and vegetable soil are (2.18±0.94)×103 Bq/kg and (1.81±0.83)×103 Bq/kg, respectively. The gross β specific activities of paddy soil and vegetable soil are (1.09±0.49)×103 Bq/kg and (0.91±0.39)×103 Bq/kg, respectively. These findings contribute to the enrichment of the background database for natural radioactivity surveys in China, providing essential data for environmental impact assessments post-operation of nuclear facilities, emergency responses to nuclear and radiation accidents, and food safety evaluations in Guangdong Province. The α/β ratio in soil obtained in this study can serve as an early warning indicator, where deviations from the established range may signal the presence of artificial radioactive contamination.