Surface-water exposure to quinoxyfen: Assessment in landscape vineyards

SummaryProtection of surface- and ground-water quality is critical for economic viability, as well as for human health and the environment. Furthermore, maintenance of the biodiversity of natural aquatic ecosystems is very important. The objective of this paper is to report methodology developed for the assessment of the surface-water exposure to pesticide using as example the fungicide quinoxyfen because persistent, lipophylic and hazard for the aquatic organisms. Exposure monitoring was carried out over two years (2005 and 2006) following historical and subsequent applications in Italian vineyards and to investigate the presence of residue in non-target areas close to the crop receiving repeated applications. After development of the monitoring procedures, surface-water contamination and biota exposure were determined during and after field treatments. Very low concentrations were found in sediments, often in contradiction with model and laboratory results, leading to the conclusion that even the historical use of quinoxyfen in vineyards within the catchment was not contaminating sediment in water bodies, which was regarded as the natural sink for such a pesticide due to its strong sorptive properties. For biota, quinoxyfen residues in benthic macroinvertebrates and fish in the vast majority of the samples were below the corresponding limit of detection (LOD). Thus long-term accumulation of quinoxyfen in sediments and organisms of the aquatic ecosystems would not be expected due main to the environmental conditions of the landscape that mitigate the overall exposure.