ABSTRACT

This study evaluated the occurrence characteristics to trace the origin and associated risks of organochlorine pesticides (OCPs) in soils from urban, suburban, and rural stormwater reservoirs. Samples were collected from the topsoil (0–15 cm) and subsoil (15-30 cm), and quantified for Ʃ₂₀OCPs using a gas chromatography-mass spectrometry (GC-MS) after extraction with n-hexane and dichloromethane. The concentrations of ∑₂₀OCPs ranged from 29.3 to 77.9 ng g⁻¹. The average concentration of Σ₂₀OCPs in the catchments and the isomer compositional pattern is in the order of urban > sub-urban > rural and ∑HCHs > ∑Chlordane > ∑Drins > ∑Endosulfan > ∑DDTs respectively. The HI levels for infants’ exposure were seven-fold that of adults' exposure and were > 1. The human exposure risk is in the order of RiskIng > RiskDerm > RiskInh. The RiskIng and RiskDerm in infants’ exposure were higher than in adults’ exposure, while the RiskInh in adult exposure was higher than that of infants' exposure. The total cancer risk was higher than the acceptable total cancer risk value. The ecological risk indicated a significant biological effect in 56% of the samples. The source apportionment showed that Ʃ₂₀OCPs were of historical and fresh inputs from the non-point and direct origin. Standard clean-up and source-directed mitigation actions should be carried out to assuage the associated risks.

摘要

本研究评估了发生特征，以追踪城市、郊区和农村雨水库土壤中有机氯农药 (OCP) 的来源和相关风险。从表土 (0–15 cm) 和底土 (15-30 cm) 收集样品，并在用正己烷和二氯甲烷萃取后，使用气相色谱-质谱 (GC-MS)对 Ʃ _{20 OCP 进行定量。}∑ ₂₀ OCPs 的浓度范围为 29.3 至 77.9 ng g ^-1。_{Σ 20}的平均浓度流域中的 OCPs 和异构体组成模式依次为城市 > 郊区 > 农村和 ∑HCHs > ∑氯丹 > ∑Drins > ∑硫丹 > ∑DDTs。婴儿暴露的 HI 水平是成人暴露的 7 倍，并且 > 1。人类暴露风险的顺序是 RiskIng > RiskDerm > RiskInh。婴儿暴露的RiskIng和RiskDerm高于成人暴露，而成人暴露的RiskInh高于婴儿暴露。总癌症风险高于可接受的总癌症风险值。生态风险表明 56% 的样本具有显着的生物学效应。来源解析显示Ʃ ₂₀OCP 是来自非点和直接来源的历史和新鲜输入。应执行标准清理和以源头为导向的缓解措施，以减轻相关风险。