北京郊区土壤中DDT(滴滴涕)残留调查及评价

    Investigation and evaluation of DDT residues in soils in the suburbs of Beijing, China

    • 摘要: 北京郊区农田表层土壤中DDT(滴滴涕)有不同程度的检出,∑DDTs的含量介于2.7008~292.4021μg/kg之间,平均值为41.6227μg/kg。总体而言,DDT及其代谢物的残留量处于较低水平。样品中p,p′-DDE和p,p′-DDT是DDT的主要残留物,p,p′-DDD/p,p′-DDE质量比为0~1.2730,大部分小于1,说明DDT主要降解为DDE类化合物,由此推断北京郊区的土地利用较多处于好氧环境中。(DDE+DDD)/DDT的比值在0.1044~1.4688之间,均值之比为0.3557,母体DDT含量占优势,DDT农药施用时间很短。经初步分析,北京郊区土壤中DDT的风险较低,但从食物链角度的风险评价结果来看,土壤中的DDT仍有一定的风险。

       

      Abstract: Soils in the suburbs of Beijing were investigated and ∑DDTs was detected in the soil samples. The results show that the concentration of ∑DDTs in the soils ranges from 2.7008 to 292.4021 μg/kg with a mean of 41.6227 μg/kg. So the residue levels of DDT and its metabolites were lower. In the samples, p,p′-DDE and p,p′-DDT are the main components of residues. The ratios of p,p′-DDD/p,p′-DDE range from 0 to 1.2730 and are <1 in most samples, indicating that DDE is mainly degenerated from DDT. Thus it may be inferred that the soils in the suburbs of Beijing are mostly in an oxyphile environment. The ratios of (DDE+DDD)/DDT are in a range of 0.1044-1.4688 with a mean of 0.3557. The time for DDT use has been very short. Analysis shows that the risk of DDT residues in soils in the study area is relatively low, but according to the bioaccumulation in terrestrial food webs, the ecological risk of the residues of DDT in soils still exits.

       

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