Tree bark measurements conducted between 2014 and 2017 in a biosphere reserve have indicated the presence of pesticides from conventional agriculture in ambient air in Germany. In the present study, we quantified pesticides and related substances in ambient air at 69 sites using passive air samplers and ventilation filter mats. It is, to our knowledge, so far the most comprehensive dataset on pesticides and their related products in ambient air in Germany.
Samples were collected in 2019 and analysed for over 500 substances, of which 109 were detected, including 28 that are not approved for use in Germany. In each sampling site, we detected one to 36 substances, including at locations such as national parks and forests, where the presence of pesticides is not expected, e.g., on the highest mountain top in the national park “Harz” (13 substances) and in the "Bavarian Forest" (six substances). Glyphosate was detected in every sample. More than half of passive air samplers contained chlorothalonil, metolachlor, pendimethalin, terbuthylazine, prothioconazole-desthio, dimethenamid, prosulfocarb, flufenacet, tebuconazole, aclonifen, chlorflurenol, hexachlorobenzene (HCB), and γ-hexachlorocyclohexane (ɣ-HCH). Filter mats also contained boscalid. The statistical analysis showed that landscape classification and agricultural intensity were the primary factors influencing the number of substances detected in ambient air. Location, such as protected areas or regions of organic farming, had only a small effect on the number of substances recorded. Long-range transport likely accounts for the findings and active sampling of ambient air will probably detect more pesticides and higher concentrations than passive air sampler data presently suggest.
Airborne pesticide mixtures are ubiquitous in Germany, which is particularly concerning for glyphosate, pendimethalin, and prosulfocarb. Deposition of these pesticides on organic products may disqualify them from the market, resulting in economic damage to farmers. Air concentrations of pesticides are a relevant issue and must be reduced.