苏南某市农田土壤环境质量评价及其分级

以苏南工业化与城市化水平较高的某市为试验区,在对该市农田土壤环境质量和污染状况进行较为系统的调研之后,对试区农田土壤的环境质量按照国家有关标准进行综合评价并分类。结果表明:单因子污染指数最小的是六六六,其次为Pb和Cr,均无超标样点;少数传统菜地和大棚菜地土壤中DDT的污染指数接近或超过1,表明其中DDT残留量已超标,单因子污染指数最为严重的是Cd。就综合污染指数而言,除水稻土均值为0.57,低于0.7,属安全外,其他3类土壤的综合污染指数均值在0.72~0.95之间,处于警戒值。试区内约有20%以上土壤综合污染指数超过1,表明土壤受到轻度污染,这是需要引起关注的。

EVALUATION AND GRADING OF SOIL ENVIRONMENTAL QUALITY OF FARMLANDS SOMEWHERE IN SOUTH JIANGSU

Results of the investigation and analysis of the soil in a well-industrialized and urbanized city in South Jiangsu showed that the single-factor pollution index with HCH was the lowest, and followed by that with Pb and Cr whereas that with Cd was the highest; however, in some traditional vegetable fields and vegetable fields in greenhouse, the single-factor pollution index with DDT came close to or over 1, indicating DDT residues exceeded the criteria in some of the soils. In regard to combined pollution index, except paddy soil with the value being 0.57, below the threshold value of 0.7, all the soils ranged between 0.72 and 0.95, all beyond the threshold value for warning. In the studied area, over 20% of the soils had their combined pollution indices beyond 1, suggesting that the soils are slightly polluted, which should arouse attention from competent authorities.