Year-round pesticide contamination of public sites near intensively managed agricultural areas in South Tyrol

Background In a previous study, we found that 45% of public playgrounds near intensively managed agricultural areas were contaminated with mainly endocrine active pesticide residues in spring. Here, we investigated potential contamination over the course of a year. Methods Residue data were analyzed from 96 grass samples collected in spring, summer, autumn, and winter by the South Tyrolean Medical Service in 19 public playgrounds, four schoolyards, and one marketplace located within intensively managed agricultural landscapes. Samples were analyzed for 281 substances using gas-chromatography and mass-spectrometry. Results A total of 32 pesticide residues and one preservative agent were found. Almost all of the sites (96%) were contaminated with at least one residue during the year; in 79% of the sites, more than one residue was found. Among the detected residues, 76% are classified as endocrine active substances, with the highest concentrations of the insecticide chlorpyrifos-methyl (0.71 mg kg(-1)), the herbicide oxadiazon (0.64 mg kg(-1)), and the fungicides captan (0.46 mg kg(-1)) and fluazinam (0.23 mg kg(-1)). The number of residues, their concentrations, and the proportion of contaminated sites varied across seasons (p < 0.001). Twenty-five residues were found in 83% of the sites in spring (median concentration 0.240 mg kg(-1)), nine in 79% of the sites in summer (0.092 mg kg(-1)), three in 50% of the sites in autumn (0.076 mg kg(-1)), and four in 17% of the sites in winter (0.155 mg kg(-1)). Playgrounds already examined in 2017 in the previous study, were more often contaminated with multiple pesticide residues in 2018 (p = 0.045). Conclusion This study confirms previous findings of widespread pesticide contamination of public sites within intensively managed agricultural areas. Moreover, pesticide residues were also found in periods with little or no pesticide application in the field (autumn and winter). It is worrisome that many of the detected residues are endocrine active substances and that some of them (thiacloprid, bupirimate, captan, folpet) are "suspected human carcinogens", according to EU authorities. Thus, we call for more effective controls of pesticide applications to minimize pesticide drift into public places.