嘧菌酯对典型农田周边水生生态风险评估

Risk Assessment of Azoxystrobin to Aquatic Ecological Systems around Farmland in China

本文评价了嘧菌酯的生物富集风险,并利用Top-Rice和China-Psem模型,针对目前中国在水稻、小麦、柑橘和马铃薯4种主要作物上登记的所有嘧菌酯单剂产品进行水生态风险评估。结果显示,我国国内在这4种作物上所登记的嘧菌酯单剂共计6种剂型,80种(截至2021年5月),其中悬浮剂占比最大,为73.75%,其次为水分散粒剂,占18.75%,可湿性粉剂、超低容量液剂、悬浮种衣剂和颗粒剂分别占3.75%、1.25%、1.25%和1.25%。根据不同剂型嘧菌酯产品的施用方法,对其在4种作物上使用进行暴露分析,结果显示,不同剂型嘧菌酯在水稻、小麦、柑橘和马铃薯上施用后,其预测环境浓度(predicted environmental concentration,PEC)范围分别为12.03~300.04、0.03~31.33、4.40~50.51和0.44~27.07μg·L^(-1)。风险表征结果显示,嘧菌酯在4种作物上使用后,针对不同分组,风险商值(risk quotient,RQ)>1的分组分别占总模拟组的82.81%、20.24%、55.56%和28.47%,但嘧菌酯生物富集风险可接受。总之,目前在中国4种作物上登记使用的嘧菌酯产品对水生生态系统风险不可忽视,但因本研究针对其施药方法模式的分析偏保守,使得评价结果具有一定保守性。

To clarify the potential risks of azoxystrobin to aquatic ecosystems,the bioaccumulation risk of azoxystrobin was evaluated.The risk assessment of aquatic ecosystems exposed to different azoxystrobin products currently registered as pesticides on rice,wheat,citrus,and potato in China were conducted via the Top-Rice model and China-Psem model.A total of 80 single agent products had been registered on these four crops till May 2021.These products were divided into six formulations.The suspension concentrate(SC)accounted for the largest portion at 73.75%,followed by the water dispersible granule(WDG)accounting for 18.75%.The wettable powders(WP),ultralow volume concentrate(UL),flowable concentrate for seed coating(FS)and granules(GR)contributed 3.75%,1.25%,1.25%and 1.25%,respectively.The results showed that applying different formulations of azoxystrobin on rice,wheat,citrus and potato,the predicted environmental concentration(PEC)of azoxystrobin ranged at 12.03~300.04μg·L^(-1),0.03~31.33μg·L^(-1),4.40~50.51μg·L^(-1),and 0.44~27.07μg·L^(-1)respectively.The risk characterization showed that after azoxystrobin was used on rice,wheat,citrus and potatoes,the groups with the RQ values greater than 1 accounted for 82.81%,20.24%,55.56%and 28.47%of the total simulation groups.In short,the results showed that the bioaccumulation risk of azoxystrobin was acceptable.However,the risk of azoxystrobin products can not be ignored for aquatic ecosystems.