Institute of Tropical and Subtropical Ecology, South China Agricultural University, Guangzhou, China.
J Environ Sci Health B. 2011;46(7):608-14. doi: 10.1080/03601234.2011.589313.
Pot experiments were conducted to examine the effects of various fertilizers, as well as soil dilution treatments on the dynamics of soil-borne DDTs [sum of dichlorodiphenyltrichloroethane (DDT), chlorodiphenyldichloroethylene (DDE) and di- chlorodiphenyldichloroethane (DDD)] and hexachlorocyclohexanes (HCHs, sum of α-HCH, β-HCH, γ-HCH and δ-HCH) and their subsequent impacts on the uptake of DDTs and HCHs by a test plant. The results show that the soil residual DDTs and HCHs concentrations in the iron-rich fertilizer-treated soil were significantly lower than those in other fertilizer-treated soils. There was a close relationship between the soil residual DDTs and the plant tissue DDTs. This suggests that the uptake rate of DDTs by the plant was dependent on the concentration of soil-borne DDTs. A less close relationship between soil residual HCHs and plant tissue HCHs was also observed. Dilution of pesticide-contaminated soil with the non-contaminated soil not only physically reduced the concentration of pesticides in the soil but also enhanced the loss of soil-borne pesticides, possibly through the improvement of soil conditions for microbial degradation. Soil dilution had a better effect on promoting the loss of soil-borne HCHs, relative to soil-borne-DDTs. The research findings obtained from this study have implications for management of heavily contaminated soils with DDTs and HCHs. Remediation of DDTs and HCHs-contaminated soils in a cost-effective way can be achieved by incorporating treatment techniques into conventional agricultural practices. Applications of iron-rich fertilizer and soil dilution treatments could cost-effectively reduce soil-borne DDTs and HCHs, and subsequently the uptake of these organochlorine pesticides by vegetables.
采用盆栽试验研究了不同肥料及土壤稀释处理对土壤中滴滴涕（DDT，包括滴滴伊、滴滴滴和滴滴涕）和六氯环己烷（HCH，包括 α-六氯环己烷、β-六氯环己烷、γ-六氯环己烷和 δ-六氯环己烷）的动态变化及其对受试植物吸收 DDTs 和 HCHs 的影响。结果表明，富铁肥料处理土壤中残留的 DDTs 和 HCHs 浓度明显低于其他肥料处理土壤。土壤中残留的 DDTs 与植物组织 DDTs 之间存在密切关系。这表明植物对 DDTs 的吸收速率取决于土壤中 DDTs 的浓度。土壤中残留 HCHs 与植物组织 HCHs 之间也存在一定的关系。用未污染土壤稀释农药污染土壤不仅可以通过物理方式降低土壤中农药的浓度，而且可以通过改善土壤微生物降解条件来促进土壤中农药的流失。与土壤中 DDTs 相比，土壤稀释对促进土壤中 HCHs 的流失具有更好的效果。本研究结果对于管理 DDTs 和 HCHs 重度污染土壤具有重要意义。通过将处理技术纳入常规农业实践，可以以较低的成本有效地修复 DDTs 和 HCHs 污染的土壤。施用富铁肥料和土壤稀释处理可以有效降低土壤中 DDTs 和 HCHs 的含量，进而降低蔬菜对这些有机氯农药的吸收。
