矿区周边农田土壤与农作物放射性核素水平检测和评价

Detection and Evaluation of the Radionuclide Levels in the Soil and Crops Around a Mine Area

为检测评价石煤矿周边农田土壤与农作物中放射性核素水平,本文测定了土壤中238U、232Th、226Ra和40K比活度,以及水稻中的放射性核素水平。结果表明,矿区周边土壤中238U、232Th、226Ra和40K的比活度均值分别为132.77Bq/kg、54.26 Bq/kg、116.55 Bq/kg和909.25 Bq/kg,采用梅内罗综合评价法得出该片区农田土壤综合污染指数为3.45,处于重度污染水平。水稻不同器官中的放射性核素水平存在差异,根系中比活度最高,其次是茎叶,籽粒中最低。水稻籽粒对土壤中放射性核素的富集指数为1.04~1.15×10-3,尤以对232Th的富集能力最强。鉴于该农田土壤处于重度污染水平,建议尽量不要种植对核素吸附能力强的作物,并采取相应措施减少核素进入食物链。

In order to detect and evaluate the level of radionuclides in the soil and crops near a mine area, this paperdetermined 238U,232Th,226Ra and 40K and radionuclides in rice. The results showed that the mean content of238U,232Th,226Raand 40K in the field was 132.77, 54.26, 116.55 and 909.25 Bq/kg, respectively. Comprehensive pollution index in the fieldwas 3.45 using the Menero＇s comprehensive evaluation method, it＇s at a serious level of pollution. Radionuclides levels indifferent organs of rice were different, and the root system was the highest in the root system, followed by the stem leaf andthe lowest in the grain. The accumulation factor of rice grain to radionuclides from the soil ranged from 1.04 ×10-3to1.15×10-3, the enrichment ability of232Th was the strongest. In view of the serious pollution level of the farmland soil, it issuggested that the crops with strong adsorption capacity of radionuclides should not be planted and corresponding measuresshould be taken to reduce nuclides to go into the food chain.