Spatial and Temporal Trends of Persistent Organic Pollutants across Europe after 15 Years of MONET Passive Air Sampling

[Image: see text] The Global Monitoring Plan of the Stockholm Convention on Persistent Organic Pollutants (POPs) was established to generate long-term data necessary for evaluating the effectiveness of regulatory measures at a global scale. After 15 years of passive air monitoring (2003–2019), MONET is the first network to produce sufficient data for the analysis of continuous long-term temporal trends of POPs in air across the entire European continent. This study reports long-term concentrations of 20 POPs monitored at 32 sites in 27 European countries. As of January 1, 2019, the concentration ranges (pg/m(3)) were 1.1–52.8 (∑(6)PCB), 0.3–8.5 (∑(12)dl-PCB), 0.007–0.175 (∑(17)PCDD/F), 0.02–2.2 (∑(9)PBDE), 0.4–24.7 (BDE 209), 0.5–247 (∑(6)DDT), 1.7–818 (∑(4)HCH), 15.8–74.7 (HCB), and 5.9–21.5 (PeCB). Temporal trends indicate that concentrations of most POPs have declined significantly over the past 15 years, with median annual decreases ranging from −8.0 to −11.5% (halving times of 6–8 years) for ∑(6)PCB, ∑(17)PCDD/F, HCB, PeCB, and ∑(9)PBDE. Furthermore, no statistically significant differences were observed in either the trends or the concentrations of specific POPs at sites in Western Europe (WEOG) compared to sites in Central and Eastern Europe (CEE), which suggests relatively uniform compound-specific distribution and removal at the continental scale.