Mechanistic modeling of persistent organic pollutant exposure among indigenous Arctic populations: motivations, challenges, and benefits

Abstract

Indigenous Arctic populations experience elevated exposures to many environmental contaminants compared with groups residing in southern Canada. This is largely due to consumption of traditional foods, some of which (ringed seals, beluga whales, narwhals, etc.) have relatively high concentrations of persistent organic pollutants. Models of contaminant fate, transport, and bioaccumulation represent powerful tools to explore this exposure issue, wherein combined models can be used to mechanistically and dynamically describe the entire sequence of events linking chemical emissions into the environment to ultimate contaminant concentrations in indigenous Arctic populations. In this review, various approaches adapted and applied to understanding indigenous Arctic contaminant exposure are explored, including early models describing body burdens in single traditional food species to more recent approaches holistically examining uptake and bioaccumulation in entire food chains. The applications of these models are also discussed, including attempts to (i) identify chemical properties favouring transport to, and bioaccumulation in, the Arctic; (ii) clarify the main determinants of temporal trends observed in indigenous Arctic biomonitoring; (iii) explore the impacts of permanent and temporary dietary transitions on current and future indigenous Arctic contaminant exposures; and (iv) correlate modeled early-life pollutant exposures with measured health impacts. The review demonstrates the effectiveness of mechanistic model approaches in investigating indigenous Arctic contaminant exposure, and confirms their utility in continued improvements to understanding associated risk in this unique population context.

Wastewater Treatment Lagoons: Local Pathways of Perfluoroalkyl Acids and Brominated Flame Retardants to the Arctic Environment

“…Due to their use in consumer products, concentrations of PFAAs, PBDEs, and NBFRs are typically higher indoors compared to outdoors. , Dry and hostile weather conditions as well as poor ventilation and small apartment size may enhance indoor levels of these contaminants in remote communities. , Furthermore, due to high transportation costs of furniture, carpets, and other household items that contain PFAAs and flame retardants, their lifetime in Arctic homes may be higher and thus they may respond slower to regulations compared to temperate regions. High-Arctic residents may also be exposed to higher amounts of PFAAs, PBDEs, and NBFRs through diet, which would impact wastewater concentrations following excretion. , …”

“…High-Arctic residents may also be exposed to higher amounts of PFAAs, PBDEs, and NBFRs through diet, which would impact wastewater concentrations following excretion. 3,4 Formation and Removal of PFAAs, PBDEs, and NBFR during Treatment. Percent formation of PFAAs and removal of PBDEs in sub-Arctic lagoons K and X were comparable to previously reported data for temperate lagoons in Canada (SI, Table SI10 and Figure SI4a,b).…”

“…The Arctic is a critical area of study for assessing persistent organic pollutants (POPs) because it is a sink for global contaminants, particularly in this era of climate change. , Residents of remote Arctic communities have elevated risk of contaminant exposure since their primary food sources contain higher levels of POPs compared to more populated regions. , Due to its low population density, the major source of POPs to the Arctic is assumed to be long-range transport of contaminants emitted from more urban/industrialized regions, via the atmosphere and/or ocean. − Although local sources have been identified, they have been primarily studied in northern Norway and northwestern Russia which contain larger cities and villages compared to other regions of the Arctic, ,, with a few exceptions. − …”

Thawing Permafrost in Arctic Coastal Communities: A Framework for Studying Risks from Climate Change

“…Indeed, unique genetic backgrounds, among other factors, may have a significant role in individual/population susceptibility to contaminant body burdens. Indigenous Arctic populations were identified as a population in need of improved contaminant exposure estimation tools [40].…”

Persistent Organic Pollutants in Polar Ecosystems: Current Situation and Future Challenges Under Climate Change

“…This process is mainly characterized by several cycles of evaporation and condensation which are a function of temperatures. High temperatures promote the evaporation of compounds whereas low temperatures their deposition from the atmosphere on soil and water [37,39,40]. They thus travel long distances and once arrived in polar regions, they accumulate there, since these ecosystems [41] are endowed with numerous environmental and climatic characteristics allowing POPs to remain intact longer and even to become more persistent [33].…”