湘南4个矿区稻田As污染状况的初步调查

通过实地调查以及土壤和水稻样品分析,研究了湘南郴州柿竹园铅锌矿、郴州界牌岭锡多金属矿、衡阳水口山有色金属矿、衡阳龙王山金矿4个矿区稻田的As污染状况.结果表明:4个矿区的稻田土壤和水稻植株均已受到严重的As污染.矿区稻田土壤As含量范围为30.0～225.7mg·kg-1,超过国家土壤环境质量3级标准;水稻根系、秸秆、谷壳、糙米As含量范围分别为115.6～588.2、4.19～20.88、1.388～5.374、0.214～0.892mg·kg-1,除部分糙米样品外,均超过我国食品中As限量卫生标准.矿区稻田土壤同时受到As和重金属的复合污染,综合污染指数(P)范围为0.76～13.12.矿区稻田的As污染主要由矿产的开采和冶炼造成,其中,水口山有色金属矿区和龙王山金矿区As污染以及As和重金属复合污染最为严重,柿竹园铅锌矿区污染面积较大,界牌岭锡多金属矿区由于发生过地质灾害改变了地表面貌,污染情况更为复杂.

Investigation on Arsenic Pollution of Paddy Fields in 4 Mining Areas in Southern Hunan

Field survey and analysis of soil and rice samples were conducted to investigate arsenic pollution of paddy fields in 4 mining areas in southern Hunan, including Shizhuyuan lead-zinc ore (Chenzhou), Jiepailing stannary (Chenzhou), Shuikoushan non-ferrous metal ore(Hengyang) and Longwangshan gold mine(Hengyang). Results showed that soils and rice plants in the four mining areas were contaminated seriously with both arsenic and heavy metals. Arsenic contents in the soils were 30.0~225.7mg·kg-1, which were higher than the 3-level of National Environmental Quality Standards for Soils. Arsenic contents in rice roots, straw, chaff, and brown were 115.6~588.2, 4.19~20.88, 1.388~5.374 and 0.214~0.892mg·kg-1, respectively. Most of them were higher than the National Hygienic Standards of Arsenic for Foods, except for part of brown rice examples. Except arsenic pollution, heavy metal pollution was also found in the soils in these mining areas, and the complex pollution indexes(P) were 0.76~13.12. This pollution was mostly resulted from exploitation and smelting of mineral resources. Among the four mining areas, the most serious complex pollution of arsenic and heavy metals happened in Shuikoushan non-ferrous mental ore area and Longwangshan gold mine area, and the largest pollution area was found in Shizhuyuan lead-zinc ore area. In Jiepailing mining area, the pollution was more complex, because of geological disaster happened in the past.