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.

As an implication of their semivolatility, aerosols play a key role in the environmental transport and fate of current-use pesticides (CUPs). Size-segregated PM10 samples were collected at each one rural, urban residential and coastal site during a pesticide application season. Out of 72 targeted CUPs, the mass size distribution of 48 CUPs was determined. Individual pesticide mass median diameters were found in the submicrometer as well as in the supermicrometer range. The findings suggest that the PM10 mass size distribution and chemical composition influenced the CUPs mass size distributions.

Nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs, OPAHs) are abundant in the atmosphere and contribute significantly to the health risk associated with inhalation of polluted air. Despite the health hazard they pose, NPAHs and OPAHs were rarely included in monitoring. The aim of this study is to provide the first multi-year temporal trends of the concentrations, composition pattern and fate of NPAHs and OPAHs in air from a site representative of background air quality conditions in central Europe. Samples were collected every second week at a rural background site in the Czech Republic during 2015 -2017. Concentrations ranged from 1.3 to 160 pg m(-3) for Sigma(17)NPAHs, from 32 to 2600 pg m-3 for Sigma(10)OPAHs and from 5.1 to 4300 pg m(-3) for Sigma O-2-heterocycles. The average particulate mass fraction (q) ranged from 0.01 +/- 0.02 (2-nitronaphthalene) to 0.83 +/- 0.22 (1-nitropyrene) for individual NPAHs and from <0.01 +/- 0.01 (dibenzofuran) to 0.96 +/- 0.08 (6H-benzo (c,d)pyren-6-one) for individual OPAHs and O-heterocycles. The multiyear variations showed downward trends for a number of targeted compounds. This suggests that on-going emission reductions of PAHs are effective also for co-emitted NPAHs and OPAHs. (C) 2020 Elsevier Ltd. All rights reserved.