Editorial to "Polycyclic aromatic compounds (PACs) in the Canadian environment: Overview of results and knowledge gaps from the special issue"

International Water Quality Guidelines for Polycyclic Aromatic Hydrocarbons: Advances to Improve Jurisdictional Uptake of Guidelines Derived Using The Target Lipid Model

A large number of different of polycyclic aromatic hydrocarbons (PAHs) have been found in environmental media, yet water quality guidelines (WQGs) are only available for a small subset of PAHs, limiting our ability to adequately assess environmental risks from these compounds. The target lipid model (TLM) was published over 20 years ago and has been extensively validated in the literature, but it has still not been widely adopted by jurisdictions to derive WQGs for PAHs. The goal of our study was to better align the methods for deriving TLM-based WQGs with international derivation protocols. This included updating the TLM with rescreened data to identify datapoints by which effect concentrations were estimated rather than measured, modernizing the statistics used to generate the hazard concentration, and testing the applicability of a chronic TLM model rather than using the acute-to-chronic ratio. The results show that the acute TLM model did not deviate substantially from the previous iteration, indicating that the model has reached a point of stability after over 20 years of testing and improvements. Water quality guidelines derived directly from a chronic TLM provided a similar level of protection as previous iterations of the TLM. The major advantage of adopting TLM-derived WQGs is the expanded list of PAH WQGs, which will allow a more fulsome quantification of environmental risks and the ability to apply the model to mixtures. Environ Toxicol Chem 2024;00:1-15. © 2023 SETAC.

Globalization-Driven Industry Relocation Significantly Reduces Arctic PAH Contamination

Industry relocation under globalization has altered the origins and strength of emission sources of many air pollutants. We develop global emission inventories of polycyclic aromatic hydrocarbons (PAHs) embodied in the production and consumption of goods and services. We implement these inventories within a global atmospheric transport model and simulate spatial-temporal changes in atmospheric concentrations of benzo[α]pyrene (BaP), the most toxic congener in unsubstituted PAHs, and depositions across the Arctic subject to global trade and industry relocation. We show that interregional trade and industry relocation dramatically reduce the atmospheric levels and deposition of BaP in the Arctic. The most significant BaP decline occurs in the European and North American Arctic regions due to attenuated sources in the two well-developed continents proximate to the polar region induced by the relocation of high-PAH pollution industries to many developing countries far from the Arctic. Although BaP emissions embodied in industry relocations in China, India, and South and Southeast Asia resulted in increased BaP contamination in the Asian Arctic, such increases in pollution are minor compared to significant BaP reductions occurring in the European and North American Arctic regions. We find that "North-to-South" industry transfer could reduce trade-related BaP contamination by 60% in the Arctic.