Risk assessment of pesticide impacts on remote ecosystems makes use of model-estimated degradation in air. Recent studies suggest these degradation rates to be overestimated, questioning current pesticide regulation. Here, we investigated the concentrations of 76 pesticides in Europe at 29 rural, coastal, mountain, and polar sites during the agricultural application season. Overall, 58 pesticides were observed in the European atmosphere. Low spatial variation of 7 pesticides suggests continental-scale atmospheric dispersal. Based on concentrations in free tropospheric air and at Arctic sites, 22 pesticides were identified to be prone to long-range atmospheric transport, which included 15 substances approved for agricultural use in Europe and 7 banned ones. Comparison between concentrations at remote sites and those found at pesticide source areas suggests long atmospheric lifetimes of atrazine, cyprodinil, spiroxamine, tebuconazole, terbuthylazine, and thiacloprid. In general, our findings suggest that atmospheric transport and persistence of pesticides have been underestimated and that their risk assessment needs to be improved.

Atmospheric Chemistry Department Leibniz Institute for Tropospheric Research Leipzig 04318 Germany

Atmospheric Sounding Station El Arenosillo National Institute for Aerospace Technology Huelva 21130 Spain

Bavarian Environment Agency Augsburg 86179 Germany

Centre for Environmental and Climate Research Lund University Lund 223 62 Sweden

Centre for Ocean and Atmospheric Sciences University of East Anglia Norwich NR4 7TJ United Kingdom

Department of Chemistry University of Crete Heraklion 715 00 Greece

Department of Physics Lund University Lund 223 63 Sweden

DRD GES Observatoire Pérenne de l'Environnement ANDRA Bure 55290 France

Environment Agency Austria Wien 1090 Austria

Environmental Research Station Schneefernerhaus Zugspitze 82475 Germany

Faculty of Science RECETOX Masaryk University Brno 602 00 Czech Republic

Finnish Meteorological Institute Helsinki 00560 Finland

Géosciences Environnement Toulouse CNRS IRD University of Toulouse Toulouse 31400 France

GeoSphere Austria Wien 1190 Austria

German Environment Agency Zugspitze 82475 Germany

Institut des Géoscience de l'Environnement University Grenoble Alpes Grenoble 38058 France

Institute for Atmospheric and Earth System Research University of Helsinki Helsinki 00100 Finland

Institute of Environmental Protection National Research Institute Warsaw 02 170 Poland

Institute of Forestry and Engineering Estonian University of Life Sciences Tartu 51014 Estonia

Institute of Physics University of Tartu Tartu 50411 Estonia

Laboratoire d'Aérologie CNRS IRD University of Toulouse Toulouse 31400 France

Laboratory of Atmospheric Chemistry Paul Scherrer Institute Villigen 5232 Switzerland

Laboratory of Chemistry and Environment CNRS Aix Marseille University Marseille 13003 France

Multiphase Chemistry Department Max Planck Institute for Chemistry Mainz 55128 Germany

National Atmospheric Observatory Košetice KošeticeCzech Hydrometeorological Institute Košetice 395 01 Czech Republic

National Centre for Atmospheric Sciences University of East Anglia Norwich NR4 7TJ United Kingdom

National Centre of Scientific Research Demokritos Institute of Nuclear Radiological Science Technology Energy and Safety ENRACT Agia Paraskevi 15310 Greece

National Institute for Public Health and the Environment Bilthoven 3721 MA the Netherlands

Norwegian Institute for Air Research Kjeller 2007 Norway

School of Natural Sciences and Centre for Climate and Air Pollution Studies Ryan Institute University of Galway Galway H91 CF50 Ireland

Slovak Hydrometeorological Institute Bratislava 833 15 Slovakia

Spanish Research Council Barcelona 08034 Spain

Swiss Federal Laboratories for Materials Science and Technology Dübendorf 8600 Switzerland

UK Centre for Ecology and Hydrology Penicuik EH260QB; United Kingdom

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