Several field campaigns have been carried out as a part of the ArcRisk project. Data from these campaigns have been used for validation of models and to investigate transport processes, especially the link between abiotic and biotic environment. Transfer of POPs from abiotic matrices into biota is an important process, but there are few studies available. This page gives some of the ArcRisk results, and provides links to databases, not only from reviews conducted in the ArcRisk project, but also links to databases where large data sets and information are stored.
Databases of contaminants
Several field campaigns have been conducted in Arctic areas during the last decade. Within the ArcRisk project, an overview over POP levels has been established in 2010. It contains abiotic compartments such as air, snow, ice and water, as well as flux of contaminants within snowpacks and ice caps. In addition, low trophic level animals (plankton) have been included. Hence, this database provides an overview over recent data available. More studies are available, especially from the years after this overview was constructed.
An ISI ‘Web of Science’ and PubMed Literature survey (12.01.2012) revealed that about 1200 publications are available in peer-reviewed international journals on POPs in Arctic environments (since 1979). The ArcRisk project has compiled an overview of recent (1999-2011) and relevant reviews on fate and distribution of POPs and mercury in Arctic and Antarctic biota. The list can be downloaded here lænk till listan “relevant reviews on fate and distribution of POPs and mercury in Arctic and Antarctic biota” in D26. Information about analytical methods and sampling strategies are available in several peer reviewed articles.
Environment Canada provides regular reports on POPs levels in the North American Arctic as a part of the Northern Contaminants Program (NCP). These data are available on the internet – Canadian Arctic Contaminants Assessment Report. The written reports can be ordered directly from the NCP secretariat.
Environmental fate of organic contaminants
POPs can be transported from the primary source to remote areas. How far, when and how they will be transported is determined by their physical-chemical properties.
Changed temperatures and precipitation patterns can affect the abiotic transport processes as well as and their uptake in biota. Snow and ice melt brings “stored” POPs to the receiving rivers and oceans. Invading species might bring pollutants into the ecosystem, species composition might change in the ecosystems and the primary production can be affected as well. These are all examples of factors and processes that the ArcRisk project aimed to elucidate.
Fate processes in snowpack
In areas of high latitude (and altitude) snow is a significant source of atmospherically derived contaminants to catchment areas as well as marine waters (Blais et al., 2001; Daly and Wania, 2004; Bergknut et al., 2010; Pućko et al., 2011). However, the release of contaminants from the snowpack and their geochemistry following periods of thaw are not well understood, particularly for chemicals that are generally more polar, ionizable and/or largely non-volatile compared to semi-volatile “legacy” POPs. To date, there is a lack of measurement data for these chemicals in the remote snowpack.
Because snow accumulation on terrestrial surfaces or sea ice is controlled by several snowpack temperature- and wind-associated processes (e.g. wind pumping) that influence its structure and moisture content (Halsall, 2004; Herbert et al., 2006), chemical phase partitioning between vapour, particles, water and ice is crucial to understand the fate of contaminants in the snowpack. When melting commences with a seasonal increase in air temperature, chemical repartitioning can occur within the snowpack, which in turn will influence their elution order and release with meltwater (Halsall, 2004; Durnford and Dastoor, 2011; Meyer and Wania, 2010).
The geochemical behaviour of substances such as mercury and PFAS in the ageing snowpack is controlled by the physical properties of the snow and chemical processes (e.g., reduction and oxidation of Hg, and ice-based chemical partitioning coefficients for POPs), as well as particle type and amount. These interactions “decides” the fate of chemicals within the snowpack and control their elution during melt, either in a “first flush” (e.g., reactive gaseous mercury (RGM) and some shorter chain PFAs, such as perfluorobutane sulfonate (PFBS)), or later for particle-associated chemicals e.g. PHg). Despite the fact that PFAS are more water soluble than hydrophobic POPs, their various chain lengths and surfactant properties ensure a variable elution order during the onset of melt, although recent fieldwork conducted as part of the ArcRisk project shows that over time these chemicals will accumulate and undergo enrichment in snow layers prior to final melt.