Little is known about the potential impact of point source contamination from seed treatment pesticide residues and degradation products in waste products in treated seed. The presence of these pesticides and their degradation products in the environment has been associated with toxic effects on non-target organisms including bees, aquatic organisms and humans. In this study, we investigated the occurrence of twenty-two pesticide residues and their degradation products in two streams receiving runoff from land-applied wet cake, applied and spilled wastewater originating at a biofuels production facility using pesticide-treated seed as a feedstock. Monthly grab and passive samples were taken between April 2021 to November 2023 and analyzed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). Eighteen out of twenty-two target pesticide residues were detected at concentrations ranging up to 344 µg/L. Results revealed varying detection frequencies and concentrations of pesticides, with clothianidin (98.6%), thiamethoxam (97.2%), and the degradation product imidacloprid desnitro (95.3%) among the most frequently detected compounds. Spatial distributions indicate higher levels pesticide concentrations occurred in an intermittent waterway downstream from a wastewater spill occurring at the facility prior to monitoring. The risk quotient analysis shows that except for the most upstream (nonpoint source) location, at least one sample from each site posed elevated exposure risk for three different trophic levels (Algae, Daphnia Magna and Fathead Minnow). Acute and chronic aquatic toxicity benchmarks set by US EPA for aquatic invertebrates were exceeded due to elevated concentrations of imidacloprid, clothianidin and thiamethoxam in both waterways. Few, if any studies have documented the occurrence of neonicotinoid degradation products at these concentrations in aquatic environments, and concentrations of desnitro imidacloprid at up to 85 µg/L is particularly concerning, given its reported toxicity. Findings from the study highlight the risks of using pesticide-treated seed as a feedstock for ethanol production.

Environmental Implication

This study describes the results of environmental monitoring conducted in an area where wastes were land applied and stockpiled from an ethanol production facility that used pesticide-treated seed corn as a feedstock. We are unaware of another location in which the feedstock to ethanol production was nearly entirely composed of pesticide-treated seedcorn. The results of this study demonstrate the environmental impacts of this practice in terms of their effect on water quality in the surrounding area.

中文翻译：

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来自使用农药处理种子的生物燃料生产设施的杀虫剂和杀菌剂残留的水生生物、归宿和潜在生态毒性


对于处理过的种子中废物中种子处理、农药残留和降解产物的点源污染的潜在影响，我们知之甚少。这些杀虫剂及其降解产物在环境中的存在与对非目标生物（包括蜜蜂、水生生物和人类）的毒性作用有关。在这项研究中，我们调查了两条溪流中 22 种农药残留及其降解产物的出现，这些溪流接收来自使用农药处理种子作为原料的生物燃料生产设施的陆地施用湿饼、施用和溢出的废水。在 2021 年 4 月至 2023 年 11 月期间采集月度抓取和被动样品，并使用液相色谱/串联质谱 （LC-MS/MS） 进行分析。在 22 种目标农药残留中，有 18 种被检测到浓度高达 344μg/L。结果显示，农药的检测频率和浓度各不相同，其中噻虫胺 （98.6%）、噻虫嗪 （97.2%） 和降解产物吡虫啉去硝基 （95.3%） 是最常检测到的化合物。空间分布表明，在监测之前，工厂发生废水泄漏后下游的间歇性水道中农药浓度较高。风险商分析表明，除了最上游（非点源）位置外，每个地点至少有一个样本对三种不同营养级（藻类、大溞和胖头鲦）构成较高的暴露风险。由于两条水道中吡虫啉、噻虫胺和噻虫嗪的浓度升高，超过了美国 EPA 为水生无脊椎动物设定的急性和慢性水生毒性基准。 很少有研究记录了在水生环境中出现这些浓度的新烟碱类降解产物，鉴于其报道的毒性，高达 85μg/L 的去硝基吡虫啉浓度尤其令人担忧。该研究的结果强调了使用经杀虫剂处理的种子作为乙醇生产原料的风险。

环境影响

本研究描述了在使用经农药处理的玉米种子作为原料的乙醇生产设施施用和储存废物的地区进行的环境监测结果。我们不知道乙醇生产原料几乎完全由杀虫剂处理的玉米种子组成的另一个地方。这项研究的结果证明了这种做法对周边地区水质的影响。