摘要
洞庭湖湿地承载着农业生产和生态平衡的重要任务,随着该地区农业的快速发展,农药作为影响生态系统结构和功能的驱动因素引起广泛的关注.环境介质中农药普遍存在,但关于洞庭湖农药系统的风险评估及来源分析的研究较少.本研究调查了洞庭湖流域氨基甲酸酯类杀虫剂、三嗪类除草剂和新烟碱类杀虫剂等35种典型农药的污染特征,使用正矩阵因子分解模型解析了农药的来源,同时采用商值法和概率法评估了农药的生态风险.结果表明:洞庭湖流域中35种典型农药全部检出,氨基甲酸酯、三嗪和新烟碱农药的浓度范围分别为1.8~1968.9、42.0~2093.1和0~469.4 ng L^(−1).根据正矩阵因子分解模型的结果,两类杀虫剂存在3种主要来源:果蔬、油料和粮食作物,贡献率分别为27.15%、33.55%和39.35%.风险商法结果表明,西玛津、环嗪酮和吡虫啉是风险最高的农药,其最大风险商分别为1632、1303和438.4,优化风险商指数分别为83.89、178.63和39.60.联合概率曲线结果表明,有7种农药对水生生态系统构成低至高风险,吡虫啉和噻虫嗪的风险最高,最大风险乘积分别为16.31%和11.03%.本研究分析了洞庭湖水体农药的污染特征、来源和生态风险,为洞庭湖流域生态保护和农药污染防治提供了科学依据.
Wetland ecosystems are crucial for maintaining ecological balance,but these systems are currently facing significant threats from agricultural expansion and pesticide use.The Dongting Lake wetland,a vital ecological and economic resource in China,is under pressure from rapid economic growth and intensive agricultural activities,resulting in excessive pesticide utilization that threatens the fragile ecosystem and sustainable development.This study investigates the contamination profiles,sources,and ecological risks of extensively used pesticides in the Dongting Lake Basin.Sampling was conducted between March and April 2023 at 22 sites(D1–D22),encompassing lake waters,inflowing rivers(Zi River,Xiang River,Yuan River,and Lishui River),and reservoirs.A comprehensive analysis identified a total of 11 carbamates,15 triazines,and 9 neonicotinoids using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry(UHPLC-MS/MS).The Positive Matrix Factorization(PMF)model was applied to identify potential pollution sources based on the spatial distribution of pesticide concentrations and cropping patterns.A multiple-level environmental risk assessment was performed assessment for selected pesticides,incorporating exposure and ecotoxicity data.The results indicate that pesticide concentrations in the Dongting Lake range from 0 to 2093.1 ng L^(−1),with detection frequencies varying from 9%to 100%.Triazine herbicides and carbamate insecticides exhibited particularly pronounced levels of contamination.Triazine herbicides showed concentration ranges of 42.0–2093.1 ng L^(−1) and detection frequencies of 9%–100%,while carbamate insecticides had an average concentration of 288.09 ng L^(−1).Among all detected pesticides,carbofuran(mean concentration:104.5 ng L^(−1)),imidacloprid(mean concentration:54.46 ng L^(−1)),and propazine(mean concentration:50.6 ng L^(−1))were the predominant compounds,with average concentrations higher than those reported in Taihu Lake(0–6.40 ng L^(−1))and Poyang Lake(0–5.84 ng L^(−1)).Based on concentration variations,crop type characteristics,and differences in sowing areas in the Dongting Lake region,the Positive Matrix Factorization model identified three primary sources of pesticide pollution:Cereal crops(39.35%),oilseed crops(33.55%),and vegetable and fruit crops(27.15%).The extensive cultivation area and high usage rates of cereal crops contributed most significantly to pesticide pollution.Risk assessments indicated that 24 pesticides posed potential ecological risks,with simazine,clomazone,and imidacloprid demonstrating high risks at over 72%of the sampling sites.The priority index highlighted 15 pesticides as posing with potential risks to aquatic organisms,including seven chemicals(clomazone,simazine,imidacloprid,methomyl,carbofuran,thiamethoxam,and atrazine)classified as medium to high risk and warranting priority attention.Joint probability curve analysis further revealed that imidacloprid and thiamethoxam posed the highest ecological risks,with maximum risk quotients of 16.31%and 11.03%,respectively,potentially threatening 15%–65%and 20%–35%of species at elevated risk.Overall,imidacloprid emerged as a typical high-risk pesticide in the Dongting Lake,consistent with findings in the Yangtze River Basin and Taihu Lake regions.This study provides crucial insights into pesticide pollution in the Dongting Lake Basin and suggests targeted strategies for pollution control.Recommendations include implementing stricter management of high-risk pesticides,particularly simazine,clomazone,imidacloprid,and thiamethoxam.Additionally,adopting crop rotation practices may help mitigate concentrated pollution from cereal crops.These findings offer scientific support for sustainable agricultural practices and wetland ecosystem protection in the Dongting Lake Basin.Future research should focus on long-term monitoring of pesticide pollution trends and their impacts on aquatic organisms to develop more comprehensive management strategies for this vital wetland ecosystem.
作者
郭新影
罗莹
杜昶
李久赢
贾世琪
徐建
王业耀
金小伟
Xinying Guo;Ying Luo;Chang Du;Jiuying Li;Shiqi Jia;Jian Xu;Yeyao Wang;Xiaowei Jin(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;State Key Laboratory of Environmental Monitoring and Quality Control for Environmental Protection,China National Environmental Monitoring Centre,Beijing 100012,China;School of Civil Engineering,Hebei University of Science&Technology,Shijiazhuang 050091,China)
出处
《科学通报》
北大核心
2025年第14期2104-2116,共13页
Chinese Science Bulletin
基金
国家自然科学基金优秀青年基金(42322710)
国家重点研发计划(2021YFC3200105)资助。
关键词
洞庭湖
农药
污染特征
来源解析
生态风险
Dongting Lake
pesticides
pollution characteristics
source apportionment
ecological risk
