Forest Fires Enhance the Emission and Transport of Persistent Organic Pollutants and Polycyclic Aromatic Hydrocarbons from the Central Himalaya to the Tibetan Plateau

Forest fires are considered one of the drivers of global carbon and aerosol emissions; however, few studies have focused on the release of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) from forest fires and their regional impacts. In this study, we estimated the emissions of POPs and PAHs from South Asian forest fires and simulated the atmospheric transport of these fire-emitted pollutants to the Tibetan plateau over the Himalaya. It was found that forest fires on the southern slopes of the central Himalaya contributed 20–30% of atmospheric POPs and PAHs during the nonmonsoon season. Under a forest fire scenario, the transport fluxes of DDTs and PAHs increased by ∼25% and ∼20%, respectively, suggesting that forest fires can enhance the transboundary transport of organic pollutants to remote regions, even breaking the barrier of the Himalaya, the highest mountain range in the world. Considering the growth of large-scale wildfires driven by climatic and anthropogenic influences in recent years, forest fires may redistribute POPs globally and thus weaken the regulatory efficiency of the Stockholm Convention to protect remote/polar regions from POP pollution.