Simulating climate change-induced alterations in bioaccumulation of organic contaminants in an Arctic marine food web

Impacts of a warming climate on concentrations of organochlorines in a fasting high arctic marine bird: Direct vs. indirect effects?

The present study examined how climate changes may impact the concentrations of lipophilic organochlorines (OCs) in the blood of fasting High Arctic common eiders (Somateria mollissima) during incubation. Polychlorinated biphenyls (PCBs), 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE), hexachlorobenzene (HCB) and four chlordane compounds (oxychlordane, trans-chlordane and trans- and cis-nonachlor) were measured in females at chick hatching (n = 223) over 11 years (2007-2017). Firstly, median HCB and p,p'-DDE concentrations increased ~75 % over the study period, whereas median chlordane concentrations doubled (except for oxychlordane). PCB concentrations, in contrast, remained stable over the study period. Secondly, both body mass and clutch size were negatively associated with OC levels, suggesting that females with high lipid metabolism redistributed more OCs from adipose tissue, and that egg production is an important elimination route for OCs. Thirdly, the direct climate effects were assessed using the mean effective temperature (ET: air temperature and wind speed) during incubation, and we hypothesized that a low ET would increase redistribution of OCs. Contrary to expectation, the ET was positively correlated to most OCs, suggesting that a warmer climate may lead to higher OCs levels, and that the impact of ET may not be direct. Finally, potential indirect impacts were examined using the Arctic Oscillation (AO) in the three preceding winters (AOwinter 1-3) as a proxy for potential long-range transport of OCs, and for local spring climate conditions. In addition, we used chlorophyll a (Chla) as a measure of spring primary production. There were negative associations between AOwinter 1 and HCB, trans-chlordane and trans-nonachlor, whereas oxychlordane and cis-chlordane were negatively associated with Chla. This suggests that potential indirect climate effects on eiders were manifested through the food chain and not through increased long-range transport, although these relationships were relatively weak.

Modelling PCB-153 in northern ecosystems across time, space, and species using the nested exposure model

There is concern over possible effects on ecosystems and humans from exposure to persistent organic pollutants (POPs) and chemicals with similar properties. The main objective of this study was to develop, evaluate, and apply the Nested Exposure Model (NEM) designed to simulate the link between global emissions and resulting ecosystem exposure while accounting for variation in time and space. NEM, using environmental and biological data, global emissions, and physicochemical properties as input, was used to estimate PCB-153 concentrations in seawater and biota of the Norwegian marine environment from 1930 to 2020. These concentrations were compared to measured concentrations in (i) seawater, (ii) an Arctic marine food web comprising zooplankton, fish and marine mammals, and (iii) Atlantic herring (Clupea harengus) and Atlantic cod (Gadus morhua) from large baseline studies and monitoring programs. NEM reproduced PCB-153 concentrations in seawater, the Arctic food web, and Norwegian fish within a factor of 0.1-31, 0.14-3.1, and 0.09-21, respectively. The model also successfully reproduced measured trophic magnification factors for PCB-153 at Svalbard as well as geographical variations in PCB-153 burden in Atlantic cod between the Skagerrak, North Sea, Norwegian Sea, and Barents Sea, but estimated a steeper decline in PCB-153 concentration in herring and cod during the last decades than observed. Using the evaluated model with various emission scenarios showed the important contribution of European and global primary emissions for the PCB-153 load in fish from Norwegian marine offshore areas.

Profiles and determinants of dicofol, endosulfans, mirex, and toxaphenes in breast milk samples from 10 prefectures in Japan

Human exposure to persistent organic pollutants (POPs) is reflected by POP concentrations in breast milk. Many studies of POPs in breast milk have been performed in Japan, but insufficient information is available about some legacy POPs (e.g., mirex and toxaphenes, included in the Stockholm Convention in 2001) and novel POPs (e.g., dicofol and endosulfans, included in the Stockholm Convention in 2019 and 2011, respectively). In this study, dicofol, endosulfan, mirex, and toxaphene concentrations in breast milk from 10 prefectures in Japan were determined. The samples were collected between 2005 and 2010, before Stockholm Convention restrictions on endosulfans and mirex were implemented. Common POPs (e.g., polychlorinated biphenyls) were also analyzed to allow the contamination statuses to be compared. The α-endosulfan and β-endosulfan concentrations were 0.26-13 and 0.012-0.82 ng/g lipid, respectively. The toxaphene #26 and #50 concentrations were <0.08-5.6 and < 0.1-8.5 ng/g lipid, respectively. The dicofol concentrations were <0.01-4.8 ng/g lipid. The mirex concentrations were <0.2-3.5 ng/g lipid. The α- and β-endosulfan concentrations on a lipid weight basis negatively correlated with the lipid contents of the milk samples (ρ = -0.65, p < 0.01 for α-endosulfan; ρ = -0.58, p < 0.01 for β-endosulfan). The toxaphene concentrations positively correlated with the lipid contents. The mirex concentrations positively correlated with the maternal age but negatively correlated with the maternal body mass index. No correlations between the dicofol concentrations and the factors were found. Principal component analysis divided the data into four groups, (1) chlordanes, dichlorodiphenyltrichloroethanes and related compounds, hexachlorobenzene, hexachlorocyclohexanes, hexachloroethane, and polychlorinated biphenyls, (2) endosulfans, (3) dicofol, dieldrin, and toxaphenes, and (4) bromodiphenyl ether 47. This indicated that bromodiphenyl ether 47, dicofol, endosulfans, and toxaphenes have different exposure routes or different kinetics to the other legacy POPs.

The influence of global climate change on accumulation and toxicity of persistent organic pollutants and chemicals of emerging concern in Arctic food webs

This review summarizes current understanding of how climate change-driven physical and ecological processes influence the levels of persistent organic pollutants (POPs) and contaminants of emerging Arctic concern (CEACs) in Arctic biota and food webs. The review also highlights how climate change may interact with other stressors to impact contaminant toxicity, and the utility of modeling and newer research tools in closing knowledge gaps on climate change-contaminant interactions. Permafrost thaw is influencing the concentrations of POPs in freshwater ecosystems. Physical climate parameters, including climate oscillation indices, precipitation, water salinity, sea ice age, and sea ice quality show statistical associations with POPs concentrations in multiple Arctic biota. Northward range-shifting species can act as biovectors for POPs and CEACs into Arctic marine food webs. Shifts in trophic position can alter POPs concentrations in populations of Arctic species. Reductions in body condition are associated with increases in levels of POPs in some biota. Although collectively understudied, multiple stressors, including contaminants and climate change, may act to cumulatively impact some populations of Arctic biota. Models are useful for predicting the net result of various contrasting climate-driven processes on POP and CEAC exposures; however, for some parameters, especially food web changes, insufficient data exists with which to populate such models. In addition to the impact of global regulations on POP levels in Arctic biota, this review demonstrates that there are various direct and indirect mechanisms by which climate change can influence contaminant exposure, accumulation, and effects; therefore, it is important to attribute POP variations to the actual contributing factors to inform future regulations and policies. To do so, a broad range of habitats, species, and processes must be considered for a thorough understanding and interpretation of the consequences to the distribution, accumulation, and effects of environmental contaminants. Given the complex interactions between climate change, contaminants, and ecosystems, it is important to plan for long-term, integrated pan-Arctic monitoring of key biota and ecosystems, and to collect ancillary data, including information on climate-related parameters, local meteorology, ecology, and physiology, and when possible, behavior, when carrying out research on POPs and CEACs in biota and food webs of the Arctic.

Influence of climate change on persistent organic pollutants and chemicals of emerging concern in the Arctic: state of knowledge and recommendations for future research

Persistent organic pollutants (POPs) have accumulated in polar environments as a result of long-range transport from urban/industrial and agricultural source regions in the mid-latitudes. Climate change has been recognized as a factor capable of influencing POP levels and trends in the Arctic, but little empirical data have been available previously. A growing number of recent studies have now addressed the consequences of climate change for the fate of Arctic contaminants, as reviewed and assessed by the Arctic Monitoring and Assessment Programme (AMAP). For example, correlations between POP temporal trends in air or biota and climate indices, such as the North Atlantic Oscillation Index, have been found. Besides the climate indices, temperature, precipitation and sea-ice were identified as important climate parameters influencing POP levels in the Arctic environment. However, the physical changes are interlinked with complex ecological changes, including new species habitats and predator/prey relationships, resulting in a vast diversity of processes directly or indirectly affecting levels and trends of POPs. The reviews in this themed issue illustrate that the complexity of physical, chemical, and biological processes, and the rapid developments with regard to both climate change and chemical contamination, require greater interdisciplinary scientific exchange and collaboration. While some climate and biological parameters have been linked to POP levels in the Arctic, mechanisms underlying these correlations are usually not understood and need more work. Going forward there is a need for a stronger collaborative approach to understanding these processes due to high uncertainties and the incremental process of increasing knowledge of these chemicals. There is also a need to support and encourage community-based studies and the co-production of knowledge, including the utilization of Indigenous Knowledge, for interpreting trends of POPs in light of climate change.

A Critical Review and Meta-Analysis of Impacts of Per- and Polyfluorinated Substances on the Brain and Behavior

Per- and polyfluoroalkyl substances (PFAS) are a class of structurally diverse synthetic organic chemicals that are chemically stable, resistant to degradation, and persistent in terrestrial and aquatic environments. Widespread use of PFAS in industrial processing and manufacturing over the last 70 years has led to global contamination of built and natural environments. The brain is a lipid rich and highly vascularized organ composed of long-lived neurons and glial cells that are especially vulnerable to the impacts of persistent and lipophilic toxicants. Generally, PFAS partition to protein-rich tissues of the body, primarily the liver and blood, but are also detected in the brains of humans, wildlife, and laboratory animals. Here we review factors impacting the absorption, distribution, and accumulation of PFAS in the brain, and currently available evidence for neurotoxic impacts defined by disruption of neurochemical, neurophysiological, and behavioral endpoints. Emphasis is placed on the neurotoxic potential of exposures during critical periods of development and in sensitive populations, and factors that may exacerbate neurotoxicity of PFAS. While limitations and inconsistencies across studies exist, the available body of evidence suggests that the neurobehavioral impacts of long-chain PFAS exposures during development are more pronounced than impacts resulting from exposure during adulthood. There is a paucity of experimental studies evaluating neurobehavioral and molecular mechanisms of short-chain PFAS, and even greater data gaps in the analysis of neurotoxicity for PFAS outside of the perfluoroalkyl acids. Whereas most experimental studies were focused on acute and subchronic impacts resulting from high dose exposures to a single PFAS congener, more realistic exposures for humans and wildlife are mixtures exposures that are relatively chronic and low dose in nature. Our evaluation of the available human epidemiological, experimental, and wildlife data also indicates heightened accumulation of perfluoroalkyl acids in the brain after environmental exposure, in comparison to the experimental studies. These findings highlight the need for additional experimental analysis of neurodevelopmental impacts of environmentally relevant concentrations and complex mixtures of PFAS.

Multiple exposure of the Boreogadus saida from bessel fjord (NE Greenland) to legacy and emerging pollutants

This work investigates the occurrence of OCPs, such as hexachlorocyclohexane (α-, β-, γ- and δ-HCH) isomers, dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolite dichlorodiphenyldichloroethylene (p,p'-DDE), endosulfan (α- and β-EDS) isomers, chlorpyrifos (CPF), dacthal (DAC) and phenolic compounds, such as 4-nonylphenol (4-NP) and its precursors nonylphenol polyethoxylates (NP1EO and NP2EO) and bisphenol A (BPA), in polar cod sampled in and outside Bessel Fjord (NE Greenland). Linear regressions between target contaminants and morphological parameters (age, length, weight, gonad- and hepato-somatic indices and Fulton K) have been also evaluated. Polar cod collected at shelf had higher average concentrations of BPA, NP1EO, NP2EO and 4-NP (muscle: 6.2, 13.2, 8.9 and 1.9 ng/g w.w., respectively; liver: 5.8, 7.5, 5.2 and 0.9 ng/g w.w. respectively), than fjord's specimens (muscle: 3.5, 9.1, 3.9 and 1.0 ng/g w.w., respectively; liver: 2.4, 5.3, 2.9 and 1.1 ng/g w.w. respectively). ΣHCHs, ΣEDSs, ΣDDTs, CPF and DAC, were more accumulated in the polar cod from the fjord (average amount in muscle: 9.1, 4.8, 7.9, 3.8 and 2.8 ng/g w.w., respectively; average amount in the liver: 11.2, 9.0, 3.8, 5.9 and 4.9 ng/g w.w., respectively) than shelf's ones (average amount in muscle 3.9, 4.5, 4.2, 0.9 and 1.2 ng/g w.w., respectively; average amount in liver 7.8, 6.3, 2.1, 3.4 and 2.5 ng/g w.w., respectively). The comparison between the concentration of target contaminants and morphologic parameters suggested a different exposure of polar cod occupying the fjord and shelf habitats, due to a combination of genetic and dietary differences, climate change effects and increased human activities.

Polycyclic aromatic compounds (PACs) in the Canadian environment: Links to global change

In this review, global change processes have been linked to polycyclic aromatic compounds (PACs) in Canada and a first national budget of sources and sinks has been derived. Sources are dominated by wildfire emissions that affect western and northern regions of Canada disproportionately due to the location of Pacific and boreal forests and the direction of prevailing winds. Wildfire emissions are projected to increase under climate warming along with releases from the thawing of glaciers and permafrost. Residential wood combustion, domestic transportation and industry contribute the bulk of anthropogenic emissions, though they are substantially smaller than wildfire emissions and are not expected to change considerably in coming years. Other sources such as accidental spills, deforestation, and re-emission of previous industrial deposition are expected to contribute anthropogenic and biogenic PACs to nearby ecosystems. PAC sinks are less well-understood. Atmospheric deposition is similar in magnitude to anthropogenic sources. Considerable knowledge gaps preclude the estimation of environmental transformations and transboundary flows, and assessing the importance of climate change relative to shifts in population distribution and energy production is not yet possible. The outlook for PACs in the Arctic is uncertain due to conflicting assessments of competing factors and limited measurements, some of which provide a baseline but have not been followed up in recent years. Climate change has led to an increase in primary productivity in the Arctic Ocean, but PAC-related impacts on marine biota appear to be modest. The net effect of changes in ecological exposure from changing emissions and environmental conditions throughout Canada remains to be seen. Evidence suggests that the PAC budget at the national scale does not represent impacts at the local or regional level. The ability to assess future trends depends on improvements to Canada's environmental measurement strategy and biogeochemical modelling capability.

Partitioning of persistent hydrophobic contaminants to different storage lipid classes

Lipids generally represent the major matrix contributing to the absorptive capacity for hydrophobic organic contaminants in aquatic ecosystems. The aim of the present study was to determine whether contaminants partition to a different degree to the different storage lipid classes: wax ester (WE) and triacylglycerol (TAG). This was undertaken by studying experimentally the partitioning of organochlorine compounds between lipids (WE or TAG) and silicone rubber phase. Our results indicate that hydrophobic compounds have a slightly higher affinity for WE than for TAG. The findings thus corroborate earlier suggestions that contaminants accumulate to a greater extent in food webs with a higher reliance of on WE, such as in the Arctic. This knowledge is of interest since it implies that possible changes in planktonic community species composition, and thereby possible changes in the lipid composition, may have consequences for accumulation of hydrophobic contaminants in apex predators. However, the magnitude of these consequences remains unknown, and there may well be other factors of importance for previously observed higher accumulation of contaminants in Arctic systems. Thus, we have here identified aspects regarding partitioning of contaminants to lipids that need further scrutiny, and there is a need for further quantitative estimates of the suggested difference in absorptive capacities for hydrophobic contaminants between WE and TAG.

Organophosphorus flame retardants and persistent, bioaccumulative, and toxic contaminants in Arctic seawaters: On-board passive sampling coupled with target and non-target analysis

Organic pollutants in the Arctic seas have been of concern to many researchers; however, the vast dynamic marine water poses challenges to their comprehensive monitoring within appropriate spatial and temporal scales in the Arctic. In this study, on-board passive sampling of organic pollutants using a self-developed device coupled with triolein-embedded cellulose acetate membranes (TECAMs) was performed during an Arctic cruise. The TECAM extracts were used for target analysis of organophosphorus flame retardants (PFRs), and non-target screening of persistent, bioaccumulative, and toxic (PBT) contaminants using two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOFMS). Sixteen chemicals were screened out as PBT contaminants from the 1500 features in the non-target analysis and further identified. Consequently, two chlorinated PFRs (tris(chloroisopropyl)phosphate and tris(1,3-dichloroisopropyl)phosphate) and four PBT contaminants (4-tert-butylphenol, 2-isopropylnaphthalene, 1,1,3-trimethyl-3-phenylindane, and 1-phenylnonan-1-one) were accurately quantified, with the temporally and spatially integrated concentrations ranging from 0.83 ng L^-1 to 20.82 ng L^-1 in the seawaters. Sources and transport of the contaminants were studied, and ocean current transport (West Spitsbergen Current, WSC) and local sources (human settlement, Arctic oil exploitation, and petroleum fuel emissions) were found to contribute to the presence of the different contaminants. Finally, annual transport fluxes of the contaminants from the North Atlantic to the Arctic Ocean by WSC were estimated, and the results indicate that their hazard to the Arctic should be concerned.

Toward Sustainable Environmental Quality: Priority Research Questions for North America

Anticipating, identifying, and prioritizing strategic needs represent essential activities by research organizations. Decided benefits emerge when these pursuits engage globally important environment and health goals, including the United Nations Sustainable Development Goals. To this end, horizon scanning efforts can facilitate identification of specific research needs to address grand challenges. We report and discuss 40 priority research questions following engagement of scientists and engineers in North America. These timely questions identify the importance of stimulating innovation and developing new methods, tools, and concepts in environmental chemistry and toxicology to improve assessment and management of chemical contaminants and other diverse environmental stressors. Grand challenges to achieving sustainable management of the environment are becoming increasingly complex and structured by global megatrends, which collectively challenge existing sustainable environmental quality efforts. Transdisciplinary, systems-based approaches will be required to define and avoid adverse biological effects across temporal and spatial gradients. Similarly, coordinated research activities among organizations within and among countries are necessary to address the priority research needs reported here. Acquiring answers to these 40 research questions will not be trivial, but doing so promises to advance sustainable environmental quality in the 21st century. Environ Toxicol Chem 2019;38:1606-1624. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Does water temperature influence the distribution and elimination of perfluorinated substances in rainbow trout (Oncorhynchus mykiss)?

Perfluorinated and polyfluorinated substances (PFASs) are widely found in freshwater ecosystems because of their resistance to degradation and their ability to accumulate in aquatic organisms. While water temperature controls many physiological processes in fish, knowledge of the effects of this factor on PFAS toxicokinetic is still limited. This study presents experimental results of internal distribution and elimination rates of two perfluorinated acid compounds, namely perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) in adult rainbow trout (Oncorhynchus mykiss) exposed to three temperatures. Dietary exposure experiments were conducted at 7 °C, 11 °C, and 19 °C and liver, blood, muscle, brain, and kidney were sampled for analysis. PFOS concentrations were comparable to or exceeded those of PFHxS, while PFHxS was eliminated faster than PFOS, whatever the temperature. Internal distribution changed significantly for both substances when fish were exposed to a range of temperatures from 7 to 19 °C. Indeed, PFOS and PFHxS relative distribution increased in blood, liver, and brain while they decreased in muscle when the water temperature rose. The water temperature variation affected the elimination half-lives, depending on the substances and organs.

Persistent organic pollutants in the polar regions and the Tibetan Plateau: A review of current knowledge and future prospects

Due to their low temperatures, the Arctic, Antarctic and Tibetan Plateau are known as the three polar regions of the Earth. As the most remote regions of the globe, the occurrence of persistent organic pollutants (POPs) in these polar regions arouses global concern. In this paper, we review the literatures on POPs involving these three polar regions. Overall, concentrations of POPs in the environment (air, water, soil and biota) have been extensively reported, with higher levels of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) detected on the Tibetan Plateau. The spatial distribution of POPs in air, water and soil in the three polar regions broadly reflects their distances away from source regions. Based on long-term data, decreasing trends have been observed for most "legacy POPs". Observations of transport processes of POPs among multiple media have also been carried out, including air-water gas exchange, air-soil gas exchange, emissions from melting glaciers, bioaccumulations along food chains, and exposure risks. The impact of climate change on these processes possibly enhances the re-emission processes of POPs out of water, soil and glaciers, and reduces the bioaccumulation of POPs in food chains. Global POPs transport model have shown the Arctic receives a relatively small fraction of POPs, but that climate change will likely increase the total mass of all compounds in this polar region. Considering the impact of climate change on POPs is still unclear, long-term monitoring data and global/regional models are required, especially in the Antarctic and on the Tibetan Plateau, and the fate of POPs in all three polar regions needs to be comprehensively studied and compared to yield a better understanding of the mechanisms involved in the global cycling of POPs.

Climate Influence on Legacy Organochlorine Pollutants in Arctic Seabirds

Changing climate can influence the transport of chemical pollutants into Arctic regions and their fate once there. However, the influence of weather or climate variables on organochlorine accumulation in Arctic wildlife, including seabirds, and associated time scale are poorly understood. We assessed the interannual relationships between a suite of weather/climate variables for time lags of 0 to 10 yr and organochlorine pollutant concentrations spanning 1975-2014 in eggs of two seabird species (northern fulmar Fulmarus glacialis, thick-billed murre Uria lomvia) that breed in the Canadian High Arctic. The majority of variability in the data was associated with declining organochlorine emissions (up to 70.2% for murres and 77.4% for fulmars). By controlling for emissions using principal component ordination and general linear modeling, correlations with the North Atlantic Oscillation (NAO) were found for fulmars and with rainfall for murres, after a time lag of 4-9 yr between weather/climate conditions and egg collection. Our results suggest that with increasingly NAO+ conditions and increasing rainfall associated with climate change, concentrations of certain organochlorines such as hexachlorobenzene and p, p'-DDE have increased, dependent on seabird species and ecology as well as partitioning characteristics of the chemical. Analysis of a truncated version of the data sets (2005-2014), consistent with typical time series lengths for environmental pollutants in Arctic wildlife, found correlations with precipitation for murres but not with NAO for fulmars, suggesting that longer time series better elucidate relationships with broad-scale climate indices. Organochlorine pollutant data sets spanning 40 years, which is rare for Arctic wildlife, for two species of seabird were assessed, and the results highlight the association between weather/climate and pollutant accumulation in Arctic food webs and the critical role of ongoing monitoring to effectively elucidate these relationships.

Temporal trends of legacy organochlorines in eggs of Canadian Arctic seabirds monitored over four decades

We compared temporal trends of legacy organochlorine pesticides and PCBs in eggs of five seabird species breeding at Prince Leopold Island in the Canadian high Arctic. Concentrations of most of the major organochlorine groups/compounds have either declined (e.g. Σ₃₅PCB, ΣDDT, ΣCBz, ΣCHL, octachlorostyrene) or shown no consistent directional change (e.g. heptachlor epoxide) since 1975 in eggs of thick-billed murres (Uria lomvia), northern fulmars (Fulmarus glacialis) and black-legged kittiwakes (Rissa tridactyla). Aside from β-HCH, which increased in most species, the major organochlorine compounds either declined or showed no trend between 1993 and 2013 in eggs of five seabird species (thick-billed murre, northern fulmar, black-legged kittiwake, black guillemot Cepphus grylle, glaucous gull Larus hyperboreus). Most of the declines occurred during the 1970s to 1990s followed by little change during the 2000s. Glaucous gull eggs had the highest concentrations of almost all organochlorines in the five years compared (1993, 1998, 2003/04, 2008, 2013), and murre eggs generally had among the lowest concentrations. The primary organochlorines found in eggs of all five species were Σ₃₅PCB, ΣDDT (mainly p,p'-DDE), ΣCBz (mainly hexachlorobenzene) and ΣCHL (mainly oxychlordane) although proportions varied by species and year. The major PCB congeners found in eggs of all five species were CB-153, -138, -118 and -180. The penta-, hexa- and heptachlorobiphenyl homologs comprised the largest proportion of Σ₃₅PCB in all five species. Although levels of most legacy organochlorines have declined since 1975, the potential for climate change to alter chemical transport pathways as well as exposure pathways in the biotic environment could affect temporal trends. Therefore, it is important to continue to monitor these legacy contaminants in order to determine how these changes will affect the temporal trends observed to date.

Polychlorinated biphenyls (PCBs) as sentinels for the elucidation of Arctic environmental change processes: a comprehensive review combined with ArcRisk project results

Polychlorinated biphenyls (PCBs) can be used as chemical sentinels for the assessment of anthropogenic influences on Arctic environmental change. We present an overview of studies on PCBs in the Arctic and combine these with the findings from ArcRisk-a major European Union-funded project aimed at examining the effects of climate change on the transport of contaminants to and their behaviour of in the Arctic-to provide a case study on the behaviour and impact of PCBs over time in the Arctic. PCBs in the Arctic have shown declining trends in the environment over the last few decades. Atmospheric long-range transport from secondary and primary sources is the major input of PCBs to the Arctic region. Modelling of the atmospheric PCB composition and behaviour showed some increases in environmental concentrations in a warmer Arctic, but the general decline in PCB levels is still the most prominent feature. 'Within-Arctic' processing of PCBs will be affected by climate change-related processes such as changing wet deposition. These in turn will influence biological exposure and uptake of PCBs. The pan-Arctic rivers draining large Arctic/sub-Arctic catchments provide a significant source of PCBs to the Arctic Ocean, although changes in hydrology/sediment transport combined with a changing marine environment remain areas of uncertainty with regard to PCB fate. Indirect effects of climate change on human exposure, such as a changing diet will influence and possibly reduce PCB exposure for indigenous peoples. Body burdens of PCBs have declined since the 1980s and are predicted to decline further.

Climate change-contaminant interactions in marine food webs: Toward a conceptual framework

Climate change is reshaping the way in which contaminants move through the global environment, in large part by changing the chemistry of the oceans and affecting the physiology, health, and feeding ecology of marine biota. Climate change-associated impacts on structure and function of marine food webs, with consequent changes in contaminant transport, fate, and effects, are likely to have significant repercussions to those human populations that rely on fisheries resources for food, recreation, or culture. Published studies on climate change-contaminant interactions with a focus on food web bioaccumulation were systematically reviewed to explore how climate change and ocean acidification may impact contaminant levels in marine food webs. We propose here a conceptual framework to illustrate the impacts of climate change on contaminant accumulation in marine food webs, as well as the downstream consequences for ecosystem goods and services. The potential impacts on social and economic security for coastal communities that depend on fisheries for food are discussed. Climate change-contaminant interactions may alter the bioaccumulation of two priority contaminant classes: the fat-soluble persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), as well as the protein-binding methylmercury (MeHg). These interactions include phenomena deemed to be either climate change dominant (i.e., climate change leads to an increase in contaminant exposure) or contaminant dominant (i.e., contamination leads to an increase in climate change susceptibility). We illustrate the pathways of climate change-contaminant interactions using case studies in the Northeastern Pacific Ocean. The important role of ecological and food web modeling to inform decision-making in managing ecological and human health risks of chemical pollutants contamination under climate change is also highlighted. Finally, we identify the need to develop integrated policies that manage the ecological and socioeconomic risk of greenhouse gases and marine pollutants.

Effects of climate change on bioaccumulation and biomagnification of polycyclic aromatic hydrocarbons in the planktonic food web of a subtropical shallow eutrophic lake in China

To date effects of climate change on bioaccumulation and biomagnification of chemical pollutants in planktonic food webs have rarely been studied. Recruitments of plankton have shifted earlier due to global warming. Global warming and precipitation patterns are projected to shift seasonally. Whether and how the shifts in plankton phenology induced by climate change will impact bioaccumulation and biomagnification of chemical pollutants, and how they will respond to climate change are largely unknown. Here, we combine data analysis of the past seven decades, high temporal resolution monitoring and model development to test this hypothesis with nine polycyclic aromatic hydrocarbons (PAHs) in the planktonic food web of a subtropical shallow eutrophic lake in China. We find biphasic correlations between both bioconcentration factors and bioaccumulation factors of the PAHs and the mean temperature, which depend on the recruitment temperatures of cyanobacteria, and copepods and cladocerans. The positive correlations between bioconcentration factors, bioaccumulation factors and the mean temperature will be observed less than approximately 13-18 days by 2050-2060 due to the shifts in plankton phenology. The PAHs and their bioaccumulation and biomagnification will respond seasonally and differently to climate change. Bioaccumulation of most of the PAHs will decrease with global warming, with higher decreasing rates appearing in winter and spring. Biomagnification of most of the PAHs from phytoplankton to zooplankton will increase with global warming, with higher increasing rates appearing in winter and spring. Our study provides novel insights into bioaccumulation and biomagnification of chemical pollutants in eutrophic waters under climate change scenarios.

Monitoring of persistent organic pollutants in the polar regions: knowledge gaps & gluts through evidence mapping

Persistent organic pollutants (POPs) are widespread compounds that accumulating in polar regions canalise through trophic webs. Although several dozens of studies have been carried out in the last decades, the information is generally scattered across a large number of literature sources. This does not allow an efficient synthesis and constraints our understanding on how address future monitoring plans and environmental conservation strategies on the Polar Regions with respect to POPs. Thus, here, we present the outcome of a systematic map (SM) to scope, screen and chart evidences from literature dealing with POPs in Polar regions. The SMs strive to produce rigorous guidelines and have recently been proposed as useful and effective tools to summarise growing bodies of research that seek to reduce bias and increase reliability, particularly in the case of high priority and controversial topics. Our SM was based on 125 polar studies, focussing on the most studied target species among those listed in the International Union for Conservation of Nature's Red List (IUCN Red List). To facilitate analysis of evidence, the studies were classified into Accumulation Monitoring (accounting for POP monitoring through sub-organismal, functional and population levels) and Food Web Monitoring approaches (accounting for contaminants monitoring through food webs). Our SM allowed us to assess and visualise, a set of both knowledge gaps and gluts and lastly a list was provided to address future research on POPs in Polar Regions.

Temporal variation in circulating concentrations of organochlorine pollutants in a pelagic seabird breeding in the high Arctic

The present study explored short-term temporal variations in circulating concentrations of 3 legacy organochlorines with different physicochemical properties (polychlorinated biphenyl 153 [PCB-153], p,p'-dichlorodiphenyldichloroethylene [DDE], and hexachlorobenzene [HCB]) in breeding kittiwakes (Rissa tridactyla) in a colony in Svalbard (78°N), Norwegian Arctic. Concentrations were measured in blood of a large number (n = 412-521 blood samples, depending on the data analyses) of prebreeding, incubating, and chick-rearing birds over a period of 5 yr (2007-2011). The PCB-153 concentrations were equal in male and female blood in the prebreeding period, whereas females had significantly lower concentrations during incubation and chick rearing, probably because of their ability to eliminate organochlorines through egg laying. A similar temporal pattern was observed with DDE, although the lower concentrations in incubating females were not significant. Males and females had similar concentrations of HCB over all reproductive stages. The concentrations of all 3 compounds varied greatly between years. The concentrations of PCB-153 tended to decline over the study period, whereas concentrations of HCB showed an increasing trend, especially among chick-rearing males late in the season. Concentrations of PCB-153 increased approximately 2.5 times from the prebreeding to the chick-rearing period, concurrent with mobilization of body lipids (reduced body mass). A similar, but less pronounced trend was found for HCB. For DDE, however, kittiwakes had the highest concentrations in the prebreeding period, suggesting relatively high exposure in their winter areas. The present study documented large variations in circulating concentrations of legacy organochlorines among and within breeding seasons in kittiwakes, but the alterations within seasons were relatively consistent from year to year. Environ Toxicol Chem 2017;36:442-448. © 2016 SETAC.

Bioaccumulation of organochlorine pesticides and polychlorinated biphenyls by loaches living in rice paddy fields of Northeast China

The concentrations of 21 organochlorine pesticide (OCP) residues and 18 polychlorinated biphenyl (PCB) congeners were measured in two loach species (Misgurnus mohoity and Paramisgurnus dabryanus) and the soils of their inhabiting rice paddies from three typical rice production bases of Northeast China to explore the main factors influencing the bioaccumulation. The concentrations of ∑18PCBs and ∑21OCPs in loaches were determined to be in the ranges of 0.14-0.76 ng g(-1) wet weight (ww) and 1.19-78.53 ng g(-1) ww, respectively. Most of loaches showed the considerably high contamination levels of dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), which accounted for over 97% of the total OCPs. The much lower maximum allowable loach consumption rates (<15 g d(-1)) indicated a high carcinogenic risk that results from the consumption of rice-field loaches. The field biota-soil accumulation factor (BSAF) was calculated as a main measure of bioaccumulation potential. The comparisons of BSAF values and the results of multivariate analysis indicated that habitat-specific environmental conditions, mainly the paddy soil contamination levels and average temperature, decisively affected the bioaccumulation of organochlorine contaminants. When the influence of lipid contents was offset, M. mohoity loaches were found to have a higher potential to accumulation PCBs and OCPs than P. dabryanus loaches, while the bioaccumulation potentials did not exhibit significant differences between juvenile and adult loaches and between male and female loaches. The octanol-water partition coefficient (KOW) was the main chemical factor influencing bioaccumulation potentials. The BSAF values presented an increasing tendency with increasing log KOW values from 6.0 to approximately 7.0, followed by a decreasing tendency with a continuous increase in log KOW values. Moreover, loaches exhibited an isomeric-selective bioaccumulation for p,p'-chlorinated DDTs, α-HCH, β-HCH, δ-HCH and cis-chlordane.

Climate change and environmental concentrations of POPs: A review

In recent years, the climate change impact on the concentrations of persistent organic pollutants (POPs) has become a topic of notable concern. Changes in environmental conditions such as the increase of the average temperature, or the UV-B radiation, are likely to influence the fate and behavior of POPs, ultimately affecting human exposure. The state of the art of the impact of climate change on environmental concentrations of POPs, as well as on human health risks, is here reviewed. Research gaps are also identified, while future studies are suggested. Climate change and POPs are a hot issue, for which wide attention should be paid not only by scientists, but also and mainly by policy makers. Most studies reported in the scientific literature are focused on legacy POPs, mainly polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and pesticides. However, the number of investigations aimed at estimating the impact of climate change on the environmental levels of polycyclic aromatic hydrocarbons (PAHs) is scarce, despite of the fact that exposure to PAHs and photodegradation byproducts may result in adverse health effects. Furthermore, no data on emerging POPs are currently available in the scientific literature. In consequence, an intensification of studies to identify and mitigate the indirect effects of the climate change on POP fate is needed to minimize the human health impact. Furthermore, being this a global problem, interactions between climate change and POPs must be addressed from an international perspective.

Simulating the uncertain effect of active carbon capping of a dioxin-polluted Norwegian fjord

Process-based multimedia models are frequently used to simulate the long-term impacts of pollutants and to evaluate potential remediation actions that can be put in place to improve or manage polluted marine environments. Many such models are detailed enough to encapsulate the different scales and processes relevant for various contaminants, yet still are tractable enough for analysis through established methods for uncertainty assessment. Inclusion and quantification of the uncertainty associated with local efficacy of remediation actions is of importance when the desired outcome in terms of human health concerns or environmental classification shows a nonlinear relationship with remediation effort. We present an updated fugacity-based environmental fate model set up to simulate the historical fate of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in the Grenland fjords, in Norway. The model is parameterized using Bayesian inference and is then used to simulate the effect of capping parts of the polluted sediments with active carbon. Great care is taken in quantifying the uncertainty regarding the efficacy of the activated carbon cap to reduce the leaching of contaminants from the sediments. The model predicts that by capping selected parts of the fjord, biota will be classified as moderately polluted approximately a decade earlier than a natural remediation scenario. Our approach also illustrates the importance of incorporating uncertainty in local remediation efforts, as the biotic concentrations scale nonlinearly with remediation effort.

Application of a novel modeling tool with multistressor functionality to support management of organic contaminants in the Baltic Sea

Organic contaminants constitute one of many stressors that deteriorate the ecological status of the Baltic Sea. When managing environmental problems in this marine environment, it may be necessary to consider the interactions between various stressors to ensure that averting one problem does not exacerbate another. A novel modeling tool, BALTSEM-POP, is presented here that simulates interactions between climate forcing, hydrodynamic conditions, and water exchange, biogeochemical cycling, and organic contaminant transport and fate in the Baltic Sea. We discuss opportunities to use the model to support different aspects of chemicals management. We exemplify these opportunities with a case study where two emission-reduction strategies for a chemical used in personal care products (decamethylcyclopentasiloxane) are evaluated, and where the confounding influence of future climate change and eutrophication on the impact of the emission-reduction strategies are assessed.

Modelling the influence of climate change on the chemical concentrations in the Baltic Sea region with the POPCYCLING-Baltic model

The effect of projected future changes in temperature, wind speed, precipitation and particulate organic carbon on concentrations of persistent organic chemicals in the Baltic Sea regional environment is evaluated using the POPCYCLING-Baltic multimedia chemical fate model. Steady-state concentrations of hypothetical perfectly persistent chemicals with property combinations that encompass the entire plausible range for non-ionizing organic substances are modelled under two alternative climate change scenarios (IPCC A2 and B2) and compared to a baseline climate scenario. The contributions of individual climate parameters are deduced in model experiments in which only one of the four parameters is changed from the baseline scenario. Of the four selected climate parameters, temperature is the most influential, and wind speed is least. Chemical concentrations in the Baltic region are projected to change by factors of up to 3.0 compared to the baseline climate scenario. For chemicals with property combinations similar to legacy persistent organic pollutants listed by the Stockholm Convention, modelled concentration ratios between two climate change scenarios and the baseline scenario range from factors of 0.5 to 2.0. This study is a first step toward quantitatively assessing climate change-induced changes in the environmental concentrations of persistent organic chemicals in the Baltic Sea region.

Environmental risk assessment of combined effects in aquatic ecotoxicology: a discussion paper

Environmental regulatory edicts within the EU, such as the regulatory framework for chemicals REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the Water Framework Directive (WFD), and the Marine Strategy Framework Directive (MSFD) focus mainly on toxicity assessment of individual chemicals although the effect of contaminant mixtures is a matter of increasing concern. This discussion paper provides an overview of the field of combined effects in aquatic ecotoxicology and addresses some of the major challenges related to assessment of combined effects in connection with environmental risk assessment (ERA) and regulation. Potentials and obstacles related to different experimental, modelling and predictive ERA approaches are described. On-going ERA guideline and manual developments in Europe aiming to incorporate combined effects of contaminants, the use of different experimental approaches for providing combined effect data, the involvement of biomarkers to characterize Mode of Action and toxicity pathways and efforts to identify relevant risk scenarios related to combined effects are discussed.

Trophic transfer of polychlorinated biphenyls (PCB) in a boreal lake ecosystem: testing of bioaccumulation models

Understanding the fate of persistent organic chemicals in the environment is fundamental information for the successful protection of ecosystems and humans. A common dilemma in risk assessment is that monitoring data reveals contaminant concentrations in wildlife, while the source concentrations, route of uptake and acceptable source concentrations remain unsolved. To overcome this problem, different models have been developed in order to obtain more precise risk estimates for the food webs. However, there is still an urgent need for studies combining modelled and measured data in order to verify the functionality of the models. Studies utilising field-collected data covering entire food webs are particularly scarce. This study aims to contribute to tackling this problem by determining the validity of two bioaccumulation models, BIOv1.22 and AQUAWEBv1.2, for application to a multispecies aquatic food web. A small boreal lake, Lake Kernaalanjärvi, in Finland was investigated for its food web structure and concentrations of PCBs in all trophic levels. Trophic magnification factors (TMFs) were used to measure the bioaccumulation potential of PCBs, and the site-specific environmental parameters were used to compare predicted and observed concentrations. Site-specific concentrations in sediment pore water did not affect the modelling endpoints, but accurate site-specific measurements of freely dissolved concentrations in water turned out to be crucial for obtaining realistic model-predicted concentrations in biota. Numerous parameters and snapshot values affected the model performances, bringing uncertainty into the process and results, but overall, the models worked well for a small boreal lake ecosystem. We suggest that these models can be optimised for different ecosystems and can be useful tools for estimating the bioaccumulation and environmental fate of PCBs.

Exploring the potential influence of climate change and particulate organic carbon scenarios on the fate of neutral organic contaminants in the Arctic environment

The main objective of this study is to explore the potential influence of climate change and particulate organic carbon scenarios on the fate of organic chemicals in the Arctic marine environment using an evaluative modeling approach. Particulate organic carbon scenarios are included to represent changes such as enhanced primary production and terrestrial inputs. Simulations are conducted for a set of hypothetical chemicals covering a wide range of partitioning property combinations using a 40-year emission scenario. Differences in model output between the default simulations (i.e. contemporary conditions) and future scenarios during the primary emission phase are limited in magnitude (typically within a factor of two), consistent with other modeling studies. The changes to particulate organic carbon levels in the Arctic Ocean assumed in the simulations exert a relatively important influence for hydrophobic organic chemicals during the primary emission phase, mitigating the potential for exposure via the pelagic food web by reducing freely-dissolved concentrations in the water column. The changes to particulate organic carbon levels are also influential in the secondary emission/depuration phase. The model results illustrate the potential importance of changes to organic carbon levels in the Arctic Ocean and support efforts to improve the understanding of organic carbon cycling and links to climate change.

Chiral chemicals as tracers of atmospheric sources and fate processes in a world of changing climate

Elimination of persistent organic pollutants (POPs) under national and international regulations reduces "primary" emissions, but "secondary" emissions continue from residues deposited in soil, water, ice and vegetation during former years of usage. In a future, secondary source controlled world, POPs will follow the carbon cycle and biogeochemical processes will determine their transport, accumulation and fate. Climate change is likely to affect mobilisation of POPs through e.g., increased temperature, altered precipitation and wind patterns, flooding, loss of ice cover in polar regions, melting glaciers, and changes in soil and water microbiology which affect degradation and transformation. Chiral compounds offer advantages for following transport and fate pathways because of their ability to distinguish racemic (newly released or protected from microbial attack) and nonracemic (microbially degraded) sources. This paper discusses the rationale for this approach and suggests applications where chiral POPs could aid investigation of climate-mediated exchange and degradation processes. Multiyear measurements of two chiral POPs, trans-chlordane and α-HCH, at a Canadian Arctic air monitoring station show enantiomer compositions which cycle seasonally, suggesting varying source contributions which may be under climatic control. Large-scale shifts in the enantioselective metabolism of chiral POPs in soil and water might influence the enantiomer composition of atmospheric residues, and it would be advantageous to include enantiospecific analysis in POPs monitoring programs.

The influence of global climate change on the scientific foundations and applications of Environmental Toxicology and Chemistry: introduction to a SETAC international workshop

This is the first of seven papers resulting from a Society of Environmental Toxicology and Chemistry (SETAC) international workshop titled "The Influence of Global Climate Change on the Scientific Foundations and Applications of Environmental Toxicology and Chemistry." The workshop involved 36 scientists from 11 countries and was designed to answer the following question: How will global climate change influence the environmental impacts of chemicals and other stressors and the way we assess and manage them in the environment? While more detail is found in the complete series of articles, some key consensus points are as follows: (1) human actions (including mitigation of and adaptation to impacts of global climate change [GCC]) may have as much influence on the fate and distribution of chemical contaminants as does GCC, and modeled predictions should be interpreted cautiously; (2) climate change can affect the toxicity of chemicals, but chemicals can also affect how organisms acclimate to climate change; (3) effects of GCC may be slow, variable, and difficult to detect, though some populations and communities of high vulnerability may exhibit responses sooner and more dramatically than others; (4) future approaches to human and ecological risk assessments will need to incorporate multiple stressors and cumulative risks considering the wide spectrum of potential impacts stemming from GCC; and (5) baseline/reference conditions for estimating resource injury and restoration/rehabilitation will continually shift due to GCC and represent significant challenges to practitioners.

Influence of global climate change on chemical fate and bioaccumulation: the role of multimedia models

Multimedia environmental fate models are valuable tools for investigating potential changes associated with global climate change, particularly because thermodynamic forcing on partitioning behavior as well as diffusive and nondiffusive exchange processes are implicitly considered. Similarly, food-web bioaccumulation models are capable of integrating the net effect of changes associated with factors such as temperature, growth rates, feeding preferences, and partitioning behavior on bioaccumulation potential. For the climate change scenarios considered in the present study, such tools indicate that alterations to exposure concentrations are typically within a factor of 2 of the baseline output. Based on an appreciation for the uncertainty in model parameters and baseline output, the authors recommend caution when interpreting or speculating on the relative importance of global climate change with respect to how changes caused by it will influence chemical fate and bioavailability.

Combined and interactive effects of global climate change and toxicants on populations and communities

Increased temperature and other environmental effects of global climate change (GCC) have documented impacts on many species (e.g., polar bears, amphibians, coral reefs) as well as on ecosystem processes and species interactions (e.g., the timing of predator-prey interactions). A challenge for ecotoxicologists is to predict how joint effects of climatic stress and toxicants measured at the individual level (e.g., reduced survival and reproduction) will be manifested at the population level (e.g., population growth rate, extinction risk) and community level (e.g., species richness, food-web structure). The authors discuss how population- and community-level responses to toxicants under GCC are likely to be influenced by various ecological mechanisms. Stress due to GCC may reduce the potential for resistance to and recovery from toxicant exposure. Long-term toxicant exposure can result in acquired tolerance to this stressor at the population or community level, but an associated cost of tolerance may be the reduced potential for tolerance to subsequent climatic stress (or vice versa). Moreover, GCC can induce large-scale shifts in community composition, which may affect the vulnerability of communities to other stressors. Ecological modeling based on species traits (representing life-history traits, population vulnerability, sensitivity to toxicants, and sensitivity to climate change) can be a promising approach for predicting combined impacts of GCC and toxicants on populations and communities.

A methodology for evaluating the influence of diets and intergenerational dietary transitions on historic and future human exposure to persistent organic pollutants in the Arctic

Concentrations of persistent organic pollutants (POPs) in Inuit populations have been observed to decrease over the last decade. The main objective of this study was to develop a methodology to quantify the potential influence of intergenerational dietary transitions on human exposure to organic contaminants in the Arctic environment using PCB-153 as a case study. Long-term (1930-2050) dynamic simulations using realistic emission estimates were conducted using linked chemical fate and bioaccumulation models. Female body burdens were calculated over time assuming five diets with varying proportions of traditional and imported food items and then used to illustrate the potential variability at a community/population level. At any given time point, individuals consuming a 100% traditional diet (i.e. high intake of ringed seal blubber) have modelled body burdens approximately 15-150 times higher than individuals consuming a 100% imported food diet. Consumption of locally-harvested fish (e.g. Arctic cod) and seal meat are also associated with comparatively low body burdens. Decreased emissions are predicted to decrease the PCB-153 body burden of 30-year old females by 6 to 13-fold from 1980 to 2020 with dietary transitions accounting for an additional factor of 2-50 (i.e. 12-650 times lower in total) depending on the type of dietary transition and the origin of the imported food items. The model results indicate that dietary transitions are an important factor underlying the variability within and between subpopulations in addition to partially explaining the observed temporal trends. Specific information on the nature and timing of dietary transitions is highly valuable when interpreting biomonitoring data.

Trophic transfer of contaminants in a changing arctic marine food web: Cumberland Sound, Nunavut, Canada

Contaminant dynamics in arctic marine food webs may be impacted by current climate-induced food web changes including increases in transient/subarctic species. We quantified food web organochlorine transfer in the Cumberland Sound (Nunavut, Canada) arctic marine food web in the presence of transient species using species-specific biomagnification factors (BMFs), trophic magnification factors (TMFs), and a multifactor model that included δ(15)N-derived trophic position and species habitat range (transient versus resident), and also considered δ(13)C-derived carbon source, thermoregulatory group, and season. Transient/subarctic species relative to residents had higher prey-to-predator BMFs of biomagnifying contaminants (1.4 to 62 for harp seal, Greenland shark, and narwhal versus 1.1 to 20 for ringed seal, arctic skate, and beluga whale, respectively). For contaminants that biomagnified in a transient-and-resident food web and a resident-only food web scenario, TMFs were higher in the former (2.3 to 10.1) versus the latter (1.7 to 4.0). Transient/subarctic species have higher tissue contaminant levels and greater BMFs likely due to higher energetic requirements associated with long-distance movements or consumption of more contaminated prey in regions outside of Cumberland Sound. These results demonstrate that, in addition to climate change-related long-range transport/deposition/revolatilization changes, increasing numbers of transient/subarctic animals may alter food web contaminant dynamics.

Factors influencing legacy pollutant accumulation in alpine osprey: biology, topography, or melting glaciers?

Persistent organic pollutants (POPs) can be transported long distances and deposited into alpine environments via cold trapping and snow scavenging processes. Here we examined biotic and abiotic factors determining contaminant variability of wildlife in alpine ecosystems. We measured POPs in eggs and plasma of an apex predator, the osprey (Pandion haliaetus) breeding in 15 mountainous watersheds across a broad latitudinal, longitudinal and altitudinal range in western Canada. After accounting for proximate biotic factors such as trophic level (δ(15)N) and carbon source (δ(13)C), variability in contaminant concentrations, including ΣDDT (sum of trichlorodiphenylethane-related compounds), toxaphene, hexachlorobenzene (HCB), total chlordane, and ΣPCBs (polychlorinated biphenyls) in osprey tissues was explained by interactions among relative size of watersheds, water bodies, elevation, and glacial input. ΣDDT in nestling plasma, for example, decreased with lake elevation, probably as a result of local past inputs from agricultural or public health usage at lower altitude sites. In contrast, toxaphene, never used as an insecticide in western Canada, increased with elevation and year-round snow and ice cover in both plasma and eggs, indicating long-range atmospheric sources as dominant for toxaphene. Lower chlorinated PCBs in plasma tended to decrease with elevation and ice cover consistent with published data and model outcomes. Temporal trends of POPs in osprey eggs are coincident with some modeled predictions of release from melting glaciers due to climate change. Currently we suggest that contaminants largely are released through annual snowpack melt and deposited in large lower elevation lakes, or some smaller lakes with poor drainage. Our study highlights the importance of understanding how biological processes integrate physical when studying the environmental chemistry of wildlife.

Climate change and environmental impacts on maternal and newborn health with focus on Arctic populations

BACKGROUND

In 2007, the Intergovernmental Panel on Climate Change (IPCC) presented a report on global warming and the impact of human activities on global warming. Later the Lancet commission identified six ways human health could be affected. Among these were not environmental factors which are also believed to be important for human health. In this paper we therefore focus on environmental factors, climate change and the predicted effects on maternal and newborn health. Arctic issues are discussed specifically considering their exposure and sensitivity to long range transported contaminants.

METHODS

Considering that the different parts of pregnancy are particularly sensitive time periods for the effects of environmental exposure, this review focuses on the impacts on maternal and newborn health. Environmental stressors known to affects human health and how these will change with the predicted climate change are addressed. Air pollution and food security are crucial issues for the pregnant population in a changing climate, especially indoor climate and food security in Arctic areas.

RESULTS

The total number of environmental factors is today responsible for a large number of the global deaths, especially in young children. Climate change will most likely lead to an increase in this number. Exposure to the different environmental stressors especially air pollution will in most parts of the world increase with climate change, even though some areas might face lower exposure. Populations at risk today are believed to be most heavily affected. As for the persistent organic pollutants a warming climate leads to a remobilisation and a possible increase in food chain exposure in the Arctic and thus increased risk for Arctic populations. This is especially the case for mercury. The perspective for the next generations will be closely connected to the expected temperature changes; changes in housing conditions; changes in exposure patterns; predicted increased exposure to Mercury because of increased emissions and increased biological availability.

CONCLUSIONS

A number of environmental stressors are predicted to increase with climate change and increasingly affecting human health. Efforts should be put on reducing risk for the next generation, thus global politics and research effort should focus on maternal and newborn health.

Monitoring of perfluorinated compounds in aquatic biota: an updated review

The goal of this article is to summarize new biological monitoring information on perfluorinated compounds (PFCs) in aquatic ecosystems (post-2005) as a followup to our critical review published in 2006. A wider range of geographical locations (e.g., South America, Russia, Antarctica) and habitats (e.g., high-mountain lakes, deep-ocean, and offshore waters) have been investigated in recent years enabling a better understanding of the global distribution of PFCs in aquatic organisms. High concentrations of PFCs continue to be detected in invertebrates, fish, reptiles, and marine mammals worldwide. Perfluorooctane sulfonate (PFOS) is still the predominant PFC detected (mean concentrations up to 1900 ng/g ww) in addition to important concentrations of long-chain perfluoroalkyl carboxylates (PFCAs; sum PFCAs up to 400 ng/g ww). More studies have evaluated the bioaccumulation and biomagnification of these compounds in both freshwater and marine food webs. Several reports have indicated a decrease in PFOS levels over time in contrast to PFCA concentrations that have tended to increase in tissues of aquatic organisms at many locations. The detection of precursor metabolites and isomers has become more frequently reported in environmental assessments yielding important information on the sources and distribution of these contaminants. The integration of environmental/ecological characteristics (e.g., latitude/longitude, salinity, and/or trophic status at sampling locations) and biological variables (e.g., age, gender, life cycle, migration, diet composition, growth rate, food chain length, metabolism, and elimination) are essential elements in order to adequately study the environmental fate and distribution of PFCs and should be more frequently considered in study design.

Global climate change and contaminants--an overview of opportunities and priorities for modelling the potential implications for long-term human exposure to organic compounds in the Arctic

This overview seeks to provide context and insight into the relative importance of different aspects related to global climate change for the exposure of Northern residents to organic contaminants. A key objective is to identify, from the perspective of researchers engaged in contaminant fate, transport and bioaccumulation modelling, the most useful research questions with respect to projecting the long-term trends in human exposure. Monitoring studies, modelling results, the magnitude of projected changes and simplified quantitative approaches are used to inform the discussion. Besides the influence of temperature on contaminant amplification and distribution, accumulation of organic contaminants in the Arctic is expected to be particularly sensitive to the reduction/elimination of sea-ice cover and also changes to the frequency and intensity of precipitation events (most notably for substances that are highly susceptible to precipitation scavenging). Changes to key food-web interactions, in particular the introduction of additional trophic levels, have the potential to exert a relatively high influence on contaminant exposure but the likelihood of such changes is difficult to assess. Similarly, changes in primary productivity and dynamics of organic matter in aquatic systems could be influential for very hydrophobic contaminants, but the magnitude of change that may occur is uncertain. Shifts in the amount and location of chemical use and emissions are key considerations, in particular if substances with relatively low long range transport potential are used in closer proximity to, or even within, the Arctic in the future. Temperature-dependent increases in emissions via (re)volatilization from primary and secondary sources outside the Arctic are also important in this regard. An increased frequency of boreal forest fires has relevance for compounds emitted via biomass burning and revolatilization from soil during/after burns but compound-specific analyses are limited by the availability of reliable emission factors. However, potentially more influential for human exposure than changes to the physical environment are changes in human behaviour. This includes the gradual displacement of traditional food items by imported foods from other regions, driven by prey availability and/or consumer preference, but also the possibility of increased exposure to chemicals used in packaging materials and other consumer products, driven by dietary and lifestyle choices.