Three years of atmospheric concentrations of nitrated and oxygenated polycyclic aromatic hydrocarbons and oxygen heterocycles at a central European background site

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.

Automated summary

This study presents the first multi-year temporal trends of NPAHs and OPAHs in air from a rural background site in the Czech Republic. The results show downward trends for several targeted compounds, indicating that emission reductions of PAHs are effective for co-emitted NPAHs and OPAHs.