Occurrence, dispersal, and associated environmental risk assessment of pesticides and their transformation products in small water bodies of Northeastern France

International audience

إنجليزي. <div><p>The widespread use of pesticides, specifically plant protection products (PPPs), has led to their transformation products (TPs) being increasingly detected in various environmental compartments, notably surface waters. This study integrates field-detected TPs into an environmental risk assessment of lentic small water bodies (LSWBs). For this purpose, measured environmental concentrations (MECs) of PPPs and TPs in 12 LSWBs, influenced by tributaries under varying agricultural pressures, were collected. Ecotoxicological data from multiple sources were compiled to calculate risk quotients (RQs) and identify potentially harmful PPPs and TPs. Among 86 molecules investigated, 17 PPPs and 30 TPs were detected, representing nearly half of those initially targeted. Ponds exhibited diverse PPP and TP compositions and levels with 12 substances posing high pesticide risk, primarily atrazine-2-hydroxy, MCPA, and metolachlor. Various pond conditions indicated moderate to high risk to aquatic organisms at corresponding MECs. Despite diverse agricultural pressures, only one site was deemed low-risk, highlighting widespread contamination risk due to co-occurring molecules. Given the prevalence of TPs in water bodies, urgent efforts are needed to gather ecotoxicological data on these contaminants to enhance environmental risk assessments. This study provides novel insights into pesticide risks in a less-studied yet common European landscape, focusing on TPs.</p></div>