Occurrence and ecotoxicological risk assessment of pesticides in sediments of the Rosetta branch,Nile River, Egypt  

作　　者：Fawzy Eissa Mahmoud Al-Sisi Khaled Ghanem 

机构地区：[1]Environment and Bio-agriculture Department,Faculty of Agriculture,Al-Azhar University,Nasr City,Cairo 11884,Egypt [2]Central Laboratory of Residue Analysis of Pesticides and Heavy Metals in Food(QCAP),Agricultural Research Center,Dokki,Giza 12311,Egypt

出　　处：《Journal of Environmental Sciences》2022年第8期21-31,共11页环境科学学报（英文版）

摘　　要：This study aimed to(1) monitor the occurrence and spatiotemporal variations of 100 pesticides in sediments collected monthly from July 2018 to June 2019 from sampling sites in El-Rahawy, Sabal, and Tala, along the Rosetta branch of the Nile River, Egypt, and(2) perform an ecological risk assessment for aquatic organisms upon exposure to the detected sediment pesticides based on the risk quotient(RQ) method. Out of the 100 pesticides monitored, 16 pesticides belonging to seven chemical families were detected, and 55% of the sediment samples were contaminated with one or more pesticide residues. The mean concentration(mg/kg dry weight(dw)) and detection frequency(%) of the four most frequently detected pesticides in the sediment samples were as follows: chlorpyrifos(0.18 mg/kg dw and 34%), p,p-DDE(0.018 mg/kg dw and 30%), cypermethrin(0.03 mg/kg dw and 14%), and deltamethrin(0.026 mg/kg dw and 13%). The spatial distribution exhibited that El-Rahawy had the highest pesticide load(2.86 mg/kg dw) among the studied sites, whereas the temporal variations revealed that the highest total pesticide concentrations were detected in winter season(1.73 mg/kg dw). Meanwhile, 12 pesticides showed high RQs(>1), posing a potential ecological risk to aquatic species that live and feed on such sediments.

关 键 词：Pesticide residues SEDIMENTS Spatiotemporal variations Risk quotient 

分 类 号：X592[环境科学与工程—环境工程] X820.4X171.5