Spatiotemporal analysis of multi-pesticide residues in the largest Central European shallow lake, Lake Balaton, and its sub-catchment area

Abstract Background The present study aimed to gain a comprehensive knowledge of the presence and environmental risks pesticide repellent residues in Lake Balaton its sub-catchment area (Hungary). A unique analysis 439 active substances 17 metabolites was carried out on surface waters one effluent wastewater as only direct discharge into from June 2017 until August 2020. Altogether 203 water- 85 sediment samples were collected analysed during 3-year monitoring period. To determine detected pesticides aquatic ecosystems, risk assessment (ERA) using two approaches (worst- general-case scenarios). Results Fifty-two insect detected, which 26 belonged herbicides (24 metabolites), 15 fungicides (15 substances), 11 insecticides (eight three nine total compounds are listed be monitored with threshold limit values (TLVs). most frequently terbuthylazine, diethyltoluamide (DEET), desethyl-atrazine, metolachlor. Glyphosate, aminomethylphosphonic acid (AMPA), DEET found highest concentrations 3.0, 2.0, 1.57 µg/L, respectively. exposures higher summer periods indicating stable seasonal pattern. According performed ERA, calculated Risk Quotients (RQs) indicated 18 high level including that had been banned for at least decade. Discussion This expands spatiotemporal occurrence inland highlights need consider widening number beyond European Water Framework Directive (EWFD). our results, additional authority legislation procedures should come force not indexed priority Union Watch List.