摘要:
在我国华北地区由于水资源的匮乏及农业生产的需要，采用污水灌溉与施用有机氯农药(OCPs)结合的农业管理方式普遍存在。大量OCPs则被引入到当地环境中，进而可能对该地区的居民产生潜在的健康风险。本研究分析石家庄市汪洋沟污灌区OCPs的残留状况，探讨污水灌溉条件下土壤-作物系统OCPs残留对土壤质量影响，并评价经口摄入及皮肤接触两种暴露途径下对人体产生的健康风险。结果表明：汪洋沟污灌区地表水、沉积物、土壤和玉米籽粒中检出了14种OCPs，其平均残留浓度分别为36.5 ng·L-1、62.9 ng·g-1、57.3 ng·g-1和27.0 ng·g-1，滴滴涕(DDTs)是其最主要的污染物，占OCPs的73%以上，其次是六六六(HCHs)和甲氧滴滴涕。р,р'-DDT是DDTs的最主要成分，其主要来源于污水灌溉或近期DDTs的使用。γ-HCH是环境HCHs残留的主要成分，其主要来源于林丹的输入和使用。此外，在该地区污灌条件下OCPs残留对土壤中C、N循环及有机S的矿化产生一定的负面影响。研究区OCPs残留对人体产生的非致癌风险和致癌风险均不超过控制标准，但经口摄入所引致的非致癌风险应予以关注，其中р,р'-DDT与γ-HCH为主要风险物质。
Abstract:
Wastewater irrigation and organochlorine pesticides (OCPs) have been widely used in agriculture land in North China, and therefore abundant organochlorine pesticide (OCPs) enter into soil and subsequently be transferred into the food supply chain where they can produce substantial adverse environmental and human health impacts. In this study, OCPs residues in wastewater irrigation area of Wangyanggou River in Shijiahzuang City and their impacts on soil environmental quality were investigated, and the bioavailability and environmental risk of OCPs through oral intake and skin contact were also evaluated. The results showed that the total 14 OCPs were detected with 36.5 ng·L-1, 62.9 ng·g-1, 57.3 ng·g-1, and 27.0 ng·g-1 in surface water, sediment, soils, and maize seeds, respectively. Among the 14 OCPs, DDTs were the dominant compounds, accounting for more than 73% of total OCPs, followed by HCHs and methoxychlor. р,р'-DDT as the domiant component of DDTs was mainly from the wastewater and pesticides used recently. The abundance of γ-HCH in HCHs may be the result of the input and usage of lindane. The OCPs in soils was an important factor for inhibiting soil carbon and nitrogen cycles and sulfur mineralization under the local wastewater irrigation condition. Although the non-cancinogenic and carcinogenic risks of OCPs to human were within the suggested tolerance, the potential damage of р,р'-DDT and γ-HCH to human health via long-term oral intake exposure should be concerned in this region.
点击查看大图
下载:
