Main sources controlling atmospheric burdens of persistent organic pollutants on a national scale

National long-term monitoring programs on persistent organic pollutants (POPs) in background air have traditionally relied active sampling techniques. Due to limited spatial coverage of samplers, questions remain (i) whether sampler sites are representative for atmospheric burdens within the larger geographical area targeted by programs, and thus (ii) if main sources affecting POPs across a nation understood. The objective this study was explore utility temporal trends concert with multiple modelling approaches understand polychlorinated biphenyls (PCBs) organochlorine pesticides (OCPs) nation. For purpose, comprehensive campaign carried out summer 2016, measuring Norway using passive sampling. Results were compared similar 2006 assess possible changes over one decade. We furthermore used Global EMEP Multi-media Modeling System (GLEMOS) Flexible Particle dispersion model (FLEXPART) predict evaluate relative importance primary emissions, secondary long-range transport (LRAT) national emissions controlling PCB-153 scale. concentrations both PCBs most OCPs generally low, exception hexachlorobenzene (HCB). A variability all study, together predictions models, suggest that LRAT dominates Norway. Model GLEMOS model, as well measured isomeric ratios, further some dictated emissions. Our results illustrate combining observations mechanistic help identify factors nation, which, turn, may be inform control strategies.