MARBEC, Ifremer, Univ Montpellier, CNRS, IRD, Sète, France.
MARBEC, Ifremer, Univ Montpellier, CNRS, IRD, Sète, France.
Sci Total Environ. 2023 Apr 1;867:161303. doi: 10.1016/j.scitotenv.2022.161303. Epub 2022 Dec 30.
To assess the risk of pesticide mixtures in lagoon waters, this study adopted a multi-step approach using integrative passive samplers (POCIS) and concentration addition (CA) toxicological models. Two French Mediterranean lagoons (Thau and Or) were monitored for a range of 68 pesticides continuously over a period of a year (2015-16). The findings revealed mixtures of dissolved pesticides with varying composition and levels over the year. The Or site contained more pesticides than Thau site (37 vs 28 different substances), at higher concentrations (0.1-58.6 ng.L at Or vs <0.1-9.9 at Thau) and with overall higher detection frequencies. All samples showed a potential chronic toxicity risk, depending on the composition and concentrations of co-occurring pesticides. In 74 % of the samples, this pesticide risk was driven by a few single substances (ametryn, atrazine, azoxystrobin, carbendazim, chlorotoluron, irgarol, diuron and metolachlor) and certain transformation products (e.g. DPMU and metolachlor OA/ESA). Individually, these were a threat for the three taxa studied (phytoplankton, crustaceans and fish). Yet even a drastic reduction of these drivers alone (up to 5 % of their current concentration) would not eliminate the toxicity risks in 56 % of the Or Lagoon samples, due to pesticide mixtures. The two CA-based approaches used to assess the combined effect of these mixtures, determined chronic potential negative impacts for both lagoons, while no acute risk was highlighted. This risk was seasonal, indicating the importance of monitoring in key periods (summer, winter and spring) to get a more realistic picture of the pesticide threat in lagoon waters. These findings suggest that it is crucial to review the current EU Water Framework Directive's risk-assessment method, as it may incorrectly determine pesticide risk in lagoons.
为了评估泻湖水中农药混合物的风险，本研究采用了多步骤方法，使用综合被动采样器（POCIS）和浓度加和（CA）毒理学模型。本研究监测了法国两个地中海泻湖（Thau 和 Or）在一年（2015-16 年）期间连续的 68 种农药。研究结果表明，在一年中，这些泻湖水中的农药混合物具有不同的组成和水平。与 Thau 泻湖相比，Or 泻湖的农药种类更多（37 种与 28 种），浓度更高（0.1-58.6ng.L 在 Or 与 <0.1-9.9 在 Thau），总检出频率更高。所有样本均显示出潜在的慢性毒性风险，这取决于共存农药的组成和浓度。在 74%的样本中，这种农药风险是由少数几种单一物质（莠去津、莠去津、唑菌胺酯、多菌灵、氯噻隆、吡虫啉、敌草隆和甲草胺）和某些转化产物（如 DPMU 和甲草胺 OA/ESA）驱动的。这些物质对三种研究的生物类群（浮游植物、甲壳类动物和鱼类）构成了威胁。然而，即使仅单独减少这些驱动因素（达到当前浓度的 5%），在 Or 泻湖的 56%的样本中，由于农药混合物的存在，仍无法消除毒性风险。使用两种基于 CA 的方法评估这些混合物的综合效应，确定了这两个泻湖存在慢性潜在负面影响，而没有突出的急性风险。这种风险具有季节性，表明在关键时期（夏季、冬季和春季）监测的重要性，以更真实地了解泻湖水中的农药威胁。这些研究结果表明，有必要审查欧盟目前的《水框架指令》风险评估方法，因为该方法可能会错误地确定泻湖中的农药风险。
