Abstract

The spatial distribution, source identification, ecotoxicological, and human health risks of 20 organochlorine pesticides (OCPs) in agricultural soils in southern Nigeria were investigated in this study. Soil samples were collected from 18 agricultural soils from 6 different locations. Soil samples were soxhlet extracted using dichloromethane/n-Hexane and purified with florisil and silica gel column. The OCPs were quantified using a gas chromatography-mass spectrometry. The concentrations of the ∑20 OCPs in the soils varied between 5.8 and 395 ng g⁻¹ for all locations and depths. The occurrence profile of OCPs was in the order of ∑Chlordane > ∑HCHs > ∑DDTs > ∑Endosulfan > ∑Endrin > Aldrin > Dieldrin. The TEC-HQ and PEC-HQ values indicated the presence of adverse and frequent ecological effects on biota from OCPs’ exposure in the soils. The HI and TCR values indicated that there were potential non-cancer and cancer risks from the OCPs’ exposure in the soils. The result of PCA and isomeric ratios showed that the OCPs in the soils were from past and fresh usage of OCPs as pesticides in the soils. The government should, therefore, set guidelines to control the use of OCPs in agricultural soils to prevent further contaminations.

摘要

在这项研究中，调查了尼日利亚南部农业土壤中20种有机氯农药（OCP）的空间分布，来源识别，生态毒理学和人类健康风险。从6个不同地点的18种农业土壤中收集土壤样品。用二氯甲烷/正己烷索氏提取土壤样品，并用弗洛里西尔和硅胶柱纯化。使用气相色谱-质谱法定量OCP。土壤中∑20 OCP的浓度在5.8至395 ng g ^-1之间变化适用于所有位置和深度。OCP的出现规律为：氯丹>六氯环己烷> ∑滴滴涕> ∑硫丹> ∑异狄氏剂>艾氏剂>狄氏剂。TEC-HQ和PEC-HQ值表明，OCP暴露于土壤中会对生物群产生不利和频繁的生态影响。HI和TCR值表明，OCPs在土壤中的暴露存在潜在的非癌和癌风险。PCA和异构体比率的结果表明，土壤中的OCP来自土壤中的农药的最新使用。因此，政府应制定指导方针，以控制在农业土壤中使用OCP，以防止进一步的污染。