粉煤灰堆场附近农田土壤硒环境污染评价

对贞观山煤灰库附近农田土壤、土壤剖面、灌溉水、母岩以及稻米,蔬菜等农作物中Se含量特征及污染现状进行了系统分析与评价.结果显示:煤灰库周围的农田土壤Se含量范围为0.15～6.12mg/kg,受到不同程度污染.土壤Se含量空间分布特征表明.离煤灰库越近的农田土壤Se污染越严重.农田土壤Se污染主要是由Se含量超标地表水灌溉以及煤灰库的长期处置所引起的,受母岩的影响不大.研究区稻米Se含量较高,为0.04～1.12mg/kg,部分稻米样品Se含量超标严重,并且受土壤Se污染影响明显.长期食用Se含量超标大米对人体健康会产生潜在危害.

Assessment of selenium environmental pollution in agricultural soil in vicinity of coal fly ash reservoir

In this study, selenium (Se) contents of agricultural soil, soil profile, irrigation water, bedrock, coal fly ash, paddy rice and vegetables in the vicinity of coal fly ash reservoir are determined. Se concentration in agricultural soils surrounding coal fly ash reservoir ranged from 0.15 to 6.12 mg/kg. The topsoil was polluted at different levels. The closer to the coal fly ash reservoir agricultural soils were, the more seriously polluted by Se they were. These results of different Se sources imply that the high Se level in agricultural soils is mainly caused by long-term of coal fly ash deposit and sewage irrigation, rather than by parent material. Se concentration in paddy rice ranged from 0.04 to 1.12 mg/kg and five paddy rice grain samples exceed the food hygiene concentration limit of 0.3 mg/kg. Se concentration in paddy rice was positively correlated with total Se concentration in soil, suggesting that Se in soil was readily transferred into the crops. Therefore, there is a potential health risk from local staple food in the study area.