Knut Breivik

• Abbasi, Golnoush; Li, Li & Breivik, Knut (2019). Global historical stocks and emissions of PBDEs. Environmental Science and Technology.  ISSN 0013-936X.  53, s 6330- 6340 . doi: 10.1021/acs.est.8b07032
• Nøst, Therese Haugdahl; Berg, Vivian; Hanssen, Linda; Rylander, Charlotta; Gaudreau, Eric; Dumas, Pierre; Breivik, Knut & Sandanger, Torkjel M (2019). Time trends of persistent organic pollutants in 30 year olds sampled in 1986, 1994, 2001 and 2007 in Northern Norway: measurements, mechanistic modeling and a comparison of study designs. Environmental Research.  ISSN 0013-9351.  172, s 684- 692 . doi: 10.1016/j.envres.2019.02.047 Full text in Research Archive.
• Carlsson, Pernilla; Breivik, Knut; Brorström-Lundén, Eva; Cousins, Ian; Christensen, Jesper; Grimalt, Joan O.; Halsall, Crispin; Kallenborn, Roland; Abass, Khaled; Lammel, Gerhard; Munthe, John; MacLeod, Matthew; Odland, Jon Øyvind; Pawlak, Janet; Rautio, Arja; Reiersen, Lars-Otto; Schlabach, Martin; Stemmler, Irene; Wilson, Simon & Wöhrnschimmel, Henry (2018). Polychlorinated biphenyls (PCBs) as sentinels for the elucidation of Arctic environmental change processes: a comprehensive review combined with ArcRisk project results. Environmental science and pollution research international.  ISSN 0944-1344.  25(23), s 22499- 22528 . doi: 10.1007/s11356-018-2625-7 Full text in Research Archive. Show summary

  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 warmerArctic, 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.

• Nøst, Therese Haugdahl; Halse, Anne Karine; Schlabach, Martin; Bäcklund, Are; Eckhardt, Sabine & Breivik, Knut (2018). Low concentrations of persistent organic pollutants (POPs) in air at Cape Verde. Science of the Total Environment.  ISSN 0048-9697.  612, s 129- 137 . doi: 10.1016/j.scitotenv.2017.08.217 Full text in Research Archive. Show summary

  Ambient air is a core medium for monitoring of persistent organic pollutants (POPs) under the Stockholm Convention and is used in studies of global transports of POPs and their atmospheric sources and source regions. Still, data based on active air sampling remain scarce in many regions. The primary objectives of this study were to (i) monitor concentrations of selected POPs in air outside West Africa, and (ii) to evaluate potential atmospheric processes and source regions affecting measured concentrations. For this purpose, an active high-volume air sampler was installed on the Cape Verde Atmospheric Observatory at Cape Verde outside the coast of West Africa. Sampling commenced in May 2012 and 43 samples (24 h sampling) were collected until June 2013. The samples were analyzed for selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and chlordanes. The concentrations of these POPs at Cape Verde were generally low and comparable to remote sites in the Arctic for several compounds. Seasonal trends varied between compounds and concentrations exhibited strong temperature dependence for chlordanes. Our results indicate net volatilization fromthe Atlantic Ocean north of Cape Verde as sources of these POPs. Air mass back trajectories demonstrated that air masses measured at Cape Verdewere generally transported fromthe Atlantic Ocean or the North African continent. Overall, the low concentrations in air at Cape Verde were likely explained by absence of major emissions in areas from which the air masses originated combined with depletion during long-range atmospheric transport due to enhanced degradation under tropical conditions (high temperatures and concentrations of hydroxyl radicals).

• Zhao, Shizhen; Breivik, Knut; Jones, Kevin C & Sweetman, Andrew J (2018). Modeling the Time-Variant Dietary Exposure of PCBs in China over the Period 1930 to 2100. Environmental Science and Technology.  ISSN 0013-936X.  52(13), s 7371- 7379 . doi: 10.1021/acs.est.8b01228 Show summary

  This study aimed for the first time to reconstruct historical exposure profiles for PCBs to the Chinese population, by examining the combined effect of changing temporal emissions and dietary transition. A long-term (1930–2100) dynamic simulation of human exposure using realistic emission scenarios, including primary emissions, unintentional emissions, and emissions from e-waste, combined with dietary transition trends was conducted by a multimedia fate model (BETR-Global) linked to a bioaccumulation model (ACC-HUMAN). The model predicted an approximate 30-year delay of peak body burden for PCB-153 in a 30-year-old Chinese female, compared to their European counterpart. This was mainly attributed to a combination of change in diet and divergent emission patterns in China. A fish-based diet was predicted to result in up to 8 times higher body burden than a vegetable-based diet (2010–2100). During the production period, a worst-case scenario assuming only consumption of imported food from a region with more extensive production and usage of PCBs would result in up to 4 times higher body burden compared to consumption of only locally produced food. However, such differences gradually diminished after cessation of production. Therefore, emission reductions in China alone may not be sufficient to protect human health from PCB-like chemicals, particularly during the period of mass production. The results from this study illustrate that human exposure is also likely to be dictated by inflows of PCBs via the environment, waste, and food.

• Arp, Hans Petter Heinrich; Morin, Nicolas; Hale, Sarah; Okkenhaug, Gudny; Breivik, Knut & Sparrevik, Magnus (2017). The mass flow and proposed management of bisphenol A in selected Norwegian waste streams. Waste Management.  ISSN 0956-053X.  60, s 775- 785 . doi: 10.1016/j.wasman.2017.01.002 Full text in Research Archive. Show summary

  Current initiatives for waste-handling in a circular economy favor prevention and recycling over incineration or landfilling. However, the impact of such a transition on environmental emissions of contaminants like bisphenol A (BPA) during waste-handling is not fully understood. To address this, a material flow analysis (MFA) was constructed for selected waste categories in Norway, for which the amount recycled is expected to increase in the future; glass, vehicle, electronic, plastic and combustible waste. Combined, 92 tons/y of BPA are disposed of via these waste categories in Norway, with 98.5% associated with plastic and electronic waste. During the model year 2011, the MFA showed that BPA in these waste categories was destroyed through incineration (60%), exported for recycling into new products (35%), stored in landfills (4%) or released into the environment (1%). Landfilling led to the greatest environmental emissions (up to 13% of landfilled BPA), and incinerating the smallest (0.001% of incinerated BPA). From modelling different waste management scenarios, the most effective way to reduce BPA emissions are to incinerate BPA-containing waste and avoid landfilling it. A comparison of environmental and human BPA concentrations with CoZMoMAN exposure model estimations suggested that waste emissions are an insignificant regional source. Nevertheless, from monitoring studies, landfill emissions can be a substantial local source of BPA. Regarding the transition to a circular economy, it is clear that disposing of less BPA-containing waste and less landfilling would lead to lower environmental emissions, but several uncertainties remain regarding emissions of BPA during recycling, particularly for paper and plastics. Future research should focus on the fate of BPA, as well as BPA alternatives, in emerging reuse and recycling processes, as part of the transition to a circular economy.

• Breivik, Knut; MacLeod, Matthew; Wania, Frank & Eckhardt, Sabine (2017). Towards a Nested Exposure Model for organic contaminants (NEM). Organohalogen Compounds.  ISSN 1026-4892.  79, s 516- 520 Full text in Research Archive.
• Glüge, Juliane; Steinlin, Christine; Schalles, Simone; Wegmann, Lukas; Josef, Tremp; Breivik, Knut; Hungerbühler, Konrad & Bogdal, Christian (2017). Import, use, and emissions of PCBs in Switzerland from 1930 to 2100. PLoS ONE.  ISSN 1932-6203.  12(10) . doi: 10.1371/journal.pone.0183768 Full text in Research Archive. Show summary

  Polychlorinated biphenyls (PCBs) are persistent organic compounds that are ubiquitously found in the environment. Their use and manufacture were restricted or banned in many countries in the 1970±1980s, however, they still persist in the antroposphere, the environment and in biota worldwide today. Conventions like the Convention on Long-range Transboundary Air Pollution encourage or bind the member parties to annually submit emission inventories of regulated air pollutants. Unfortunately, several member states have not yet reported PCB emissions. The identification and quantification of stocks and emissions sources is, however, an important precondition to handle and remove the remaining reservoirs of PCBs and, thus, to be able to reduce emissions and subsequently environmental exposure. Here, we estimate past, present, and future emissions of PCBs to air in Switzerland and provide emission factors for all relevant emission categories. Switzerland hereby represents a typical developed industrial country, and most of the assumptions and parameters presented here can be used to calculate PCB emission also for other countries. PCB emissions to air are calculated using a dynamic mass flow and emissions model for Switzerland, which is run for the years 1930±2100. The results point out the importance of the use of PCBs in open applications, which have largely been previously overlooked. Additionally, we show that PCBs will persist in applications during the coming decades with ongoing emissions. Especially the use of PCBs in open applications will cause Swiss emissions to remain above 100 kg PCB per year, even after the year 2030. Our developed model is available in Excel/VBA and can be downloaded with this article.

• Iqbal, Mehreen; Syed, Jabir Hussain; Breivik, Knut; Chaudhry, Muhammad Jamshed Iqbal; Li, Jun; Zhang, Gan & Malik, Riffat Naseem (2017). E-Waste Driven Pollution in Pakistan: The First Evidence of Environmental and Human Exposure to Flame Retardants (FRs) in Karachi City. Environmental Science and Technology.  ISSN 0013-936X.  51(23), s 13895- 13905 . doi: 10.1021/acs.est.7b03159 Full text in Research Archive. Show summary

  Informal e-waste recycling activities have been shown to be a major emitter of organic flame retardants (FRs), contributing to both environmental and human exposure to laborers at e-waste recycling sites in some West African countries, as well as in China and India. The main objectiveof this study was to determine the levels of selected organic FRs in both air and soil samples collected from areas with intensive informal e-waste recycling activities in Karachi, Pakistan. Dechlorane Plus (DP) and “novel” brominated flame retardants (NBFRs) were often detected in high concentrations in soils, while phosphorous-based FRs (OPFRs) dominated atmospheric samples. Among individual substances and substance groups, decabromodiphenyl ether (BDE-209) (726 ng/g), decabromodiphenyl ethane (DBDPE) (551 ng/g), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) (362 ng/g) and tri-phenyl-phosphate (ΣTPP) (296 ng/g) were found to be prevalent in soils, while OPFR congeners (5903-24986 ng/m3) were prevalent in air. The two major e-waste recycling areas (Shershah and Lyari) were highly contaminated with FRs, suggesting informal e-waste recycling activities as a major emission source of FRs in the environment in Karachi City. However, the hazards associated with exposure to PM2.5 appear to exceed those attributed to exposure to selected FRs via inhalation and soil ingestion.

• Krogseth, Ingjerd Sunde; Undeman, Emma Maria; Evenset, Anita; Christensen, Guttorm N.; Whelan, Mick; Breivik, Knut & Warner, Nicholas Alexander (2017). Elucidating the Behavior of Cyclic Volatile Methylsiloxanes in a Subarctic Freshwater Food Web: A Modeled and Measured Approach. Environmental Science and Technology.  ISSN 0013-936X.  51, s 12489- 12497 . doi: 10.1021/acs.est.7b03083 Full text in Research Archive. Show summary

  Cyclic volatile methylsiloxanes (cVMS) are used in personal care products and emitted to aquatic environments through wastewater effluents, and their bioaccumulation potential is debated. Here, a new bentho-pelagic version of the ACC-HUMAN model was evaluated for polychlorinated biphenyls (PCBs) and applied to cVMS in combination with measurements to explore their bioaccumulation behavior in a subarctic lake. Predictions agreed better with measured PCB concentrations in Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) when the benthic link was included than in the pelagic-only model. Measured concentrations of decamethylcyclopentasiloxane (D5) were 60 ± 1.2 (Chironomidae larvae), 107 ± 4.5 (pea clams Pisidium sp.), 131 ± 105 (three-spined sticklebacks: Gasterosteus aculeatus), 41 ± 38 (char), and 9.9 ± 5.9 (trout) ng g-1 wet weight. Concentrations were lower for octamethylcyclotetrasiloxane (D4) and dodecamethylcyclohexasiloxane (D6), and none of the cVMS displayed trophic magnification. Predicted cVMS concentrations were lower than measured in benthos, but agreed well with measurements in fish. cVMS removal through ventilation was an important predicted loss mechanism for the benthic-feeding fish. Predictions were highly sensitive to the partition coefficient between organic carbon and water (KOC) and its temperature dependence, as this controlled bioavailability for benthos (the main source of cVMS for fish).

• Krogseth, Ingjerd Sunde; Whelan, Mick; Christensen, Guttorm N; Breivik, Knut; Evenset, Anita & Warner, Nicholas Alexander (2017). Understanding of Cyclic Volatile Methyl Siloxane Fate in a High Latitude Lake Is Constrained by Uncertainty in Organic Carbon− Water Partitioning. Environmental Science and Technology.  ISSN 0013-936X.  51(1), s 401- 409 . doi: 10.1021/acs.est.6b04828 Full text in Research Archive. Show summary

  Cyclic volatile methyl siloxanes (cVMS) are emitted to aquatic environments with wastewater effluents. Here, we evaluate the environmental behavior of three cVMS compounds (octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6)) in a high latitude lake (Storvannet, 70°N 23°E), experiencing intermittent wastewater emissions and high latitude environmental conditions (low temperatures and seasonal ice cover). Measured cVMS concentrations in lake water were below detection limits in both March and June 2014. However, mean concentrations in sediments were 207 ± 30, 3775 ± 973 and 848 ± 211 ng g−1 organic carbon for D4, D5 and D6, respectively. To rationalize measurements, a fugacity-based model for lakes (QWASI) was parametrized for Storvannet. The key removal process for cVMS from the lake was predicted to be advection due to the low hydraulic retention time of the lake, followed by volatilization. Predicted cVMS behavior was highly sensitive to the partition coefficient between organic carbon and water (KOC) and its temperature dependence. Predictions indicated lower overall persistence with decreasing temperature due to enhanced partitioning from sediments to water. Inverse modeling to predict steady-state emissions from cVMS concentrations in sediment provided unrealistically high emissions, when evaluated against measured concentrations in sewage. However, high concentrations of cVMS in sediment and low concentrations in water could be explained via a hypothetical dynamic emission scenario consistent with combined sewer overflows. The study illustrates the importance of considering compound-specific behavior of emerging contaminants that may differ from legacy organic contaminants.

• Nøst, Therese Haugdahl; Sandanger, Torkjel M; Nieboer, Evert; Odland, Jon Øyvind & Breivik, Knut (2017). The impacts of emission trends of POPs on human concentration dynamics: Lessons learned from a longitudinal study in Norway (1979-2007). International Journal of Hygiene and Environmental Health.  ISSN 1438-4639.  220(4), s 776- 781 . doi: 10.1016/j.ijheh.2017.01.015 Full text in Research Archive. Show summary

  Background. In this short communication, our focus is on the relationship between human concentrations of select persistent organic pollutants (POPs) and environmental emissions. It is based on a longitudinal study (1979-2007) conducted in Norway. Objectives. Our aim was to extract general insights from observed and predicted temporal trends in human concentrations of 49 POPs to assist in the design and interpretation of future monitoring studies. Discussion. Despite considerable decline for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) since 1986, the sum of the targeted POPs increased from 1979 until 2001, with per- and polyfluorinated alkyl substances (PFASs) dominating recent blood burden measurements. Specifically, the time trends in serum concentrations of POPs, exemplified by PCB-153, 1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene) (DDT) and perfluorooctane sulfonic acid (PFOS), resembled the trends in available data on their emissions, production or use. These observations suggest that interpretations of human biomonitoring data on persistent compounds must consider historic emissions, which likely vary spatially across the globe. Based on the different temporal trends observed across POP groups, it is evident that generalizations regarding temporal aspects have limitations. Conclusion. The discussion herein underscores the importance of understanding temporal variations in environmental emissions when designing and interpreting human biomonitoring studies.

• Yadav, Ishwar Chandra; Devi, Ningombam linthoingambi; Li, Jun; Zhang, Gan & Breivik, Knut (2017). Possible emissions of POPs in plain and hilly areas of Nepal: Implications for source apportionment and health risk assessment. Environmental Pollution.  ISSN 0269-7491.  220, s 1289- 1300 . doi: 10.1016/j.envpol.2016.10.102 Full text in Research Archive. Show summary

  Ambient air is a core media chosen for monitoring under the Stockholm Convention on POPs. While extensive monitoring of POPs in ambient air has been carried out in some parts of the globe, there are still regions with very limited information available, such as some developing countries as Nepal. This study therefore aims to target the occurrence of selected POPs in Nepal in suspected source areas/more densely populated regions. Four potential source regions in Nepal were furthermore targeted as it was hypothesized that urban areas at lower altitudes (Birgunj and Biratnagar located at approximately 86 and 80 m.a.s.l.) would be potentially more affected by OCPs because of more intensive agricultural activities in comparison to urban areas at higher altitudes (Kathmandu, Pokhara located 1400 and 1135 m.a.s.l). As some of these areas could also be impacted by LRAT, air mass back trajectories during the sampling period were additionally evaluated using HYSPLIT. The concentrations of overall POPs were twice as high in plain areas in comparison to hilly areas. DDTs and HCHs were most frequently detected in the air samples. The high p,p'-DDT/(pp'-DDE + pp'-DDD) ratio as well as the low o,p'-DDT/p,p'-DDT ratio observed in this study was inferred as continuing use of technical DDT. High levels of Sum26PCBs were linked to proximity to highly urbanized and industrial areas, indicating the potential source of PCBs. The measured concentrations of legacy POPs in air from this study is assumed to represent a negligible health risk through inhalation of ambient air, however, other modes of human exposure could still be relevant in Nepal. The air mass backward trajectory analysis revealed that most of the air masses sampled originated from India and the Bay of Bengal.

• Zhao, Shizhen; Breivik, Knut; Liu, Guorui; Zheng, Minghui; Jones, Kevin C & Sweetman, Andrew J (2017). Long-Term Temporal Trends of Polychlorinated Biphenyls and Their Controlling Sources in China. Environmental Science and Technology.  ISSN 0013-936X.  51(5), s 2838- 2845 . doi: 10.1021/acs.est.6b05341 Full text in Research Archive. Show summary

  Polychlorinated biphenyls (PCBs) are industrial organic contaminants identified as persistent, bioaccumulative, toxic (PBT) and subject to long-range transport (LRT) with global scale significance. This study focuses on a reconstruction and prediction for China of long-term emission trends of intentionally and unintentionally produced (UP) Σ7PCBs (UP-PCBs, from the manufacture of steel, cement and sinter iron) and their re-emissions from secondary sources (e.g., soils and vegetation), using a dynamic fate model (BETR-Global). Contemporary emission estimates combined with predictions from the multimedia fate model suggest that primary sources still dominate, although unintentional sources are predicted to become a main contributor from 2035 for PCB-28. Imported e-waste is predicted to play an increasing role until 2020-2030 on a national scale due to the decline of IP emissions. Hypothetical emission scenarios suggest that China could become a potential source to neighbouring regions with a net output of ~0.4 t year-1 in the case of 7 PCBs around 2050. However, future emission scenarios and hence model results will be dictated by the efficiency of control measures.

• Breivik, Knut; Armitage, James M; Wania, Frank; Sweetman, Andrew J & Jones, Kevin C (2016). Tracking the Global Distribution of Persistent Organic Pollutants Accounting for E-Waste Exports to Developing Regions. Environmental Science and Technology.  ISSN 0013-936X.  50(2), s 798- 805 . doi: 10.1021/acs.est.5b04226 Full text in Research Archive. Show summary

  Elevated concentrations of various industrial-use persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), have been reported in some developing areas in sub-tropical and tropical regions known to be destinations of e-waste. We used a recent inventory of the global generation and exports of e-waste to develop various global scale emission scenarios for industrial-use organic contaminants (IUOCs). For representative IUOCs (RIUOCs), only hypothetical emissions via passive volatilization from e-waste were considered whereas for PCBs, historical emissions throughout the chemical life-cycle (i.e., manufacturing, use, disposal) were included. The environmental transport and fate of RIUOCs and PCBs were then simulated using the BETR Global 2.0 model. Export of e-waste is expected to increase and sustain global emissions beyond the baseline scenario, which assumes no export. A comparison between model predictions and observations for PCBs in selected recipient regions generally suggests a better agreement when exports are accounted for. This study may be the first to integrate the global transport of IUOCs in waste with their long range transport in air and water. The results call for integrated chemical management strategies on a global scale.

• Chakraborty, Paromita; Zhang, Gan; Li, Jun; Selvaraj, Sakthivel; Breivik, Knut & Jones, Kevin C (2016). Soil concentrations, occurrence, sources and estimation of air–soil exchange of polychlorinated biphenyls in Indian cities. Science of the Total Environment.  ISSN 0048-9697.  562, s 928- 934 . doi: 10.1016/j.scitotenv.2016.03.009 Full text in Research Archive. Show summary

  Past studies have shown potentially increasing levels of polychlorinated biphenyls (PCBs) in the Indian environment. This is the first attempt to investigate the occurrence of PCBs in surface soil and estimate diffusive air-soil exchange, both on a regional scale as well as at local level within the metropolitan environment of India. From the north, New Delhi and Agra, east, Kolkata, west, Mumbai and Goa and Chennai and Bangalore in the southern India were selected for this study. 33 PCB congeners were quantified in surface soil and possible sources were derived using positive matrix factorization model. Net flux directions of PCBs were estimated in seven major metropolitan cities of India along urban-suburban-rural transects. Mean Σ33PCBs concentration in soil (12 ng/g dry weight) was nearly twice the concentration found in global background soil, but in line with findings from Pakistan and urban sites of China. Higher abundance of the heavier congeners (6CB–8CB) was prevalent mostly in the urban centers. Cities like Chennai, Mumbai and Kolkata with evidence of ongoing PCB sources did not show significant correlation with soil organic carbon (SOC). This study provides evidence that soil is acting as sink for heavy weight PCB congeners and source for lighter congeners. Atmospheric transport is presumably a controlling factor for occurrence of PCBs in less polluted sites of India.

• Hung, Hayley; Katsoyiannis, Athanasios A.; Brorström-Lunden, Eva; Olafsdottir, Kristin; Aas, Wenche; Breivik, Knut; Nizzetto, Pernilla Bohlin; Sigurdsson, Arni; Hakola, Hannele; Bossi, Rossana; Skov, Henrik; Sverko, Ed; Barresi, Enzo; Fellin, Phil & Wilson, Simon (2016). Temporal trends of Persistent Organic Pollutants (POPs) in arctic air: 20 years of monitoring under the Arctic Monitoring and Assessment Programme (AMAP). Environmental Pollution.  ISSN 0269-7491.  217, s 52- 61 . doi: 10.1016/j.envpol.2016.01.079 Full text in Research Archive. Show summary

  Temporal trends of Persistent Organic Pollutants (POPs) measured in Arctic air are essential in understanding long-range transport to remote regions and to evaluate the effectiveness of national and international chemical control initiatives, such as the Stockholm Convention (SC) on POPs. Long-term air monitoring of POPs is conducted under the Arctic Monitoring and Assessment Programme (AMAP) at four Arctic stations: Alert, Canada; Storhofði, Iceland; Zeppelin, Svalbard; and Pallas, Finland, since the 1990s using high volume air samplers. Temporal trends observed for POPs in Arctic air are summarized in this study. Most POPs listed for control under the SC, e.g. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and chlordanes, are declining slowly in Arctic air, reflecting the reduction of primary emissions during the last two decades and increasing importance of secondary emissions. Slow declining trends also signifies their persistence and slow degradation under the Arctic environment, such that they are still detectable after being banned for decades in many countries. Some POPs, e.g. hexachlorobenzene (HCB) and lighter PCBs, showed increasing trends at specific locations, which may be attributable to warming in the region and continued primary emissions at source. Polybrominated diphenyl ethers (PBDEs) do not decline in air at Canada's Alert station but are declining in European Arctic air, which may be due to influence of local sources at Alert and the much higher historical usage of PBDEs in North America. Arctic air samples are screened for chemicals of emerging concern to provide information regarding their environmental persistence (P) and long-range transport potential (LRTP), which are important criteria for classification as a POP under SC. The AMAP network provides consistent and comparable air monitoring data of POPs for trend development and acts as a bridge between national monitoring programs and SC's Global Monitoring Plan (GMP).

• Nøst, Therese Haugdahl; Breivik, Knut; Wania, Frank; Rylander, Charlotta; Odland, Jon Øyvind & Sandanger, Torkjel M (2016). Estimating Time-Varying PCB Exposures Using Person-Specific Predictions to Supplement Measured Values: A Comparison of Observed and Predicted Values in Two Cohorts of Norwegian Women. Environmental Health Perspectives.  ISSN 0091-6765.  124(3), s 299- 305 . doi: 10.1289/ehp.1409191 Full text in Research Archive. Show summary

  Background: Studies on health effects of polychlorinated biphenyls (PCBs) call for an understanding of past and present human exposure. Time-resolved mechanistic models may supplement information on concentrations in individuals obtained from measurements and/or statistical approaches, if they can be shown to reproduce empirical data. Objectives: Here we evaluate the capability of one such mechanistic model to reproduce measured PCB concentrations in individual Norwegian women. We also assess individual life course concentrations. Methods: Concentrations of four PCB congeners in pregnant women (n= 310, sampled in 2007-2009) and postmenopausal women (n= 244, 2005) were compared to person-specific predictions obtained with CoZMoMAN, an emission-based environmental fate and human food-Chain bioaccumulation model. Person-specific predictions were also made with statistical regression models including dietary and lifestyle variables and concentrations. Results: CoZMoMAN accurately reproduced medians and ranges of measured concentrations in the two study groups. Further, rank correlations between measurements and predictions from both CoZMoMAN and regression analyses were strong (Spearman`s r >0.67). Precision in quartile assignments from predictions was strong overall as evaluated by Weighted Cohen`s Kappa >0.6. Simulations indicated large inter-individual differences in concentrations experienced in the past. Conclusions: The mechanistic model reproduced all measurements of PCB concentrations within a factor of ten and subject ranking and quartile assignments were overall largely consistent, although weak within each study group. Contamination histories for individuals predicted by CoZMoMAN revealed variation between study subjects, particularly in the timing of peak concentrations. Mechanistic models provide individual PCB exposure metrics that could serve as valuable supplements to measurements.

• Halse, Anne Karine; Schlabach, Martin; Schuster, Jasmin K; Jones, Kevin C; Steinnes, Eiliv & Breivik, Knut (2015). Endosulfan, pentachlorobenzene and short-chain chlorinated paraffins in background soils from Western Europe. Environmental Pollution.  ISSN 0269-7491.  196, s 21- 28 . doi: 10.1016/j.envpol.2014.09.009 Full text in Research Archive. Show summary

  Soils are major reservoirs for many persistent organic pollutants (POPs). In this study, “newly” regulated POPs i.e. sum endosulfans (a-endosulfan, b-endosulfan, endosulfan sulfate), pentachlorobenzene (PeCB), and short-chain chlorinated paraffins (SCCPs) were determined in background samples from woodland (WL) and grassland (GL) surface soil, collected along an existing latitudinal UK-Norway transect. Statistical analysis, complemented with plots showing the predicted equilibrium distribution and mobility potential, was then explored to discuss factors controlling their spatial distribution. SCCPs were detected with the highest average concentrations (35 ± 100 ng/g soil organic matter (SOM)), followed by sum endosulfans (3 ± 3 ng/g SOM) and PeCB (1 ± 1 ng/g SOM). PeCB and sum endosulfans share many similarities in their distribution in these background soils as well as with several legacy POPs. A steep decline in concentrations of SCCPs with increasing latitude indicates that their occurrence is dictated by proximity to source regions, while concentrations of Sendosulfans peaked in regions experiencing elevated precipitation rates.

• Iqbal, Mehreen; Breivik, Knut; Syed, Jabir Hussain; Malik, Riffat Naseem; Li, Jun; Zhang, Gan & Jones, Kevin C. (2015). Emerging issue of e-waste in Pakistan: A review of status, research needs and data gaps. Environmental Pollution.  ISSN 0269-7491.  207, s 308- 318 . doi: 10.1016/j.envpol.2015.09.002 Full text in Research Archive. Show summary

  This review article focuses on the current situation of e-waste in Pakistan with the emphasis on defining the major e-waste recycling sites, current and future domestic generation of e-waste, hidden flows or import of e-waste and discusses various challenges for e-waste management. Needed policy interventions and possible measures to be taken at governmental level are discussed to avoid the increasing problem of e-waste in the country. Our findings highlight that there is still a general lack of reliable data, inventories and research studies addressing e-waste related issues in the context of environmental and human health in Pakistan. There is therefore a critical need to improve the current knowledge base, which should build upon the research experience from other countries which have experienced similar situations in the past. Further research into these issues in Pakistan is considered vital to help inform future policies/control strategies as already successfully implemented in other countries.

• Nøst, Therese Haugdahl; Halse, Anne Karine; Randall, Scott Gary; Borgen, Anders; Schlabach, Martin; Paul, Alak; Rahman, Atiqur & Breivik, Knut (2015). High concentrations of organic contaminants in air from ship breaking activities in Chittagong, Bangladesh. Environmental Science and Technology.  ISSN 0013-936X.  49, s 11372- 11380 . doi: 10.1021/acs.est.5b03073 Full text in Research Archive.
• Rylander, Charlotta; Sandanger, Torkjel M; Nøst, Therese Haugdahl; Breivik, Knut & Lund, Eiliv (2015). Combining plasma measurements and mechanistic modeling to explore the effect of POPs on type 2 diabetes mellitus in Norwegian women. Environmental Research.  ISSN 0013-9351.  142, s 365- 373 . doi: 10.1016/j.envres.2015.07.002 Show summary

  The number of studies on persistent organic pollutants (POPs) and type 2 diabetes mellitus (T2DM) is growing steadily. Although concentrations of many POPs in humans have decreased substantially, only some studies consider temporal and inter-individual changes in POP concentrations when assessing exposure. Here we combined plasma measurements with mechanistic modelling to generate complementary exposure measures to our single blood draw after disease diagnosis. Blood was collected between 2003-2006 from 106 subjects with T2DM and 106 age-matched controls, and POP concentrations were compared after adjustment for relevant risk factors and multiple testing. Area under the curve (AUC) of PCB-153 from birth until age 18, representing early-life exposure, and AUC from birth until time of diagnosis were generated as well as examples of life-time exposure trajectories using a mechanistic exposure model. The rank sum of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs, OR=16.9 (95% CI: 3.05- 93.6)) as well as β-hexachlorocyclohexane (β-HCH, OR=203.8 (95% CI: 11.5- 3620)) and 1, 1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p’-DDE, OR=11.3 (95% CI: 2.55- 49.9)) were associated with T2DM. Neither of the AUCs reflecting early life exposure and total life-time exposure at the time of diagnosis were associated with the disease. The predicted life course trajectories display clear differences within and between individuals in the past and suggest that a single blood draw provide limited information on POP exposure earlier in life. The predicted AUCs for PCB-153 did not support the positive association between T2DM and measured blood concentration of certain POPs. This may suggest that the model is either too simplistic and/or that strength of the association may vary through life and with time to/past diagnosis.

• Breivik, Knut; Armitage, James M & Wania, Frank (2014). Long-range transport of industrial-use organic contaminants with e-waste: Possible implications for emissions, transport and environmental exposure. Organohalogen Compounds.  ISSN 1026-4892.  76, s 372- 375 Full text in Research Archive.
• Breivik, Knut; Armitage, James M; Wania, Frank & Jones, Kevin C (2014). Tracking the global generation and exports of e-waste. Do existing estimates add up?. Environmental Science and Technology.  ISSN 0013-936X.  48(15), s 8735- 8743 . doi: 10.1021/es5021313 Full text in Research Archive. Show summary

  The transport of discarded electronic and electrical appliances (e-waste) to developing regions has received considerable attention, but it is difficult to assess the significance of this issue without a quantitative understanding of the amounts involved. The main objective of this study is to track the global transport of e-wastes by compiling and constraining existing estimates of the amount of e-waste generated domestically in each country MGEN, exported from countries belonging to the Organization for Economic Cooperation and Development (OECD) MEXP, and imported in countries outside of the OECD MIMP. Reference year is 2005 and all estimates are given with an uncertainty range. Estimates of MGEN obtained by apportioning a global total of ∼35,000 kt (range 20,000−50,000 kt) based on a nation’s gross domestic product agree well with independent estimates of MGEN for individual countries. Import estimates MIMP to the countries believed to be the major recipients of e-waste exports from the OECD globally (China, India, and five West African countries) suggests that ∼5,000 kt (3,600 kt−7,300 kt) may have been imported annually to these non-OECD countries alone, which represents ∼23% (17%−34%) of the amounts of e-waste generated domestically within the OECD. MEXP for each OECD country is then estimated by applying this fraction of 23% to its MGEN. By allocating each country’s MGEN, MIMP, MEXP and MNET = MGEN + MIMP − MEXP, we can map the global generation and flows of e-waste from OECD to non-OECD countries. While significant uncertainties remain, we note that estimated import into seven non-OECD countries alone are often at the higher end of estimates of exports from OECD countries.

• Katsoyiannis, Athanasios & Breivik, Knut (2014). Model-based evaluation of the use of polycyclic aromatic hydrocarbons molecular diagnostic ratios as a source identification tool. Environmental Pollution.  ISSN 0269-7491.  184, s 488- 494 . doi: 10.1016/j.envpol.2013.09.028 Full text in Research Archive. Show summary

  Polycyclic Aromatic Hydrocarbons (PAHs) molecular diagnostic ratios (MDRs) are unitless concentration ratios of pair-PAHs with the same molecular weight (MW); MDRs have long been used as a tool for PAHs source identification purposes. In the present paper, the efficiency of the MDR methodology is evaluated through the use of a multimedia fate model, the calculation of characteristic travel distances (CTD) and the estimation of air concentrations for individual PAHs as a function of distance from an initial point source. The results show that PAHs with the same MW are sometimes characterized by substantially different CTDs and therefore their air concentrations and hence MDRs are predicted to change as the distance from the original source increases. From the assessed pair-PAHs, the biggest CTD difference is seen for Fluoranthene (107 km) vs. Pyrene (26 km). This study provides a strong indication that MDRs are of limited use as a source identification tool.

• Krogseth, Ingjerd Sunde; Warner, Nicholas Alexander; Christensen, Guttorm N.; Whelan, Mick; Breivik, Knut; Evenset, Anita & Wasbotten, Ingar Halvorsen (2014). Understanding the fate and bioaccumulation of cyclic volatile methyl siloxanes in Arctic Lakes. Organohalogen Compounds.  ISSN 1026-4892.  76, s 186- 189 Full text in Research Archive.
• McLachlan, Michael S; Kierkegaard, Amelie; Radke, Michael; Sobek, Anna; Malmvärn, Anna; Alsberg, Tomas; Arnot, Jon A; Brown, Trevor N.; Wania, Frank; Breivik, Knut & Xu, Shihe (2014). Using model-based screening to help discover unknown environmental contaminants. Environmental Science and Technology.  ISSN 0013-936X.  48(13), s 7264- 7271 . doi: 10.1021/es5010544 Full text in Research Archive. Show summary

  Of the tens of thousands of chemicals in use, only a small fraction has been analyzed in environmental samples. To effectively identify environmental contaminants, methods to prioritize chemicals for analytical method development are required. We used a high throughput model of chemical emissions, fate, and bioaccumulation to identify chemicals likely to have high concentrations in specific environmental media, and we prioritized these for target analysis. This model-based screening was applied to 215 organosilicon chemicals culled from industrial chemical production statistics. The model-based screening prioritized several recognized organosilicon contaminants and generated hypotheses leading to the selection of three chemicals that have not previously been identified as potential environmental contaminants for target analysis. Trace analytical methods were developed and the chemicals were analyzed in air, sewage sludge, and sediment. All three substances were found to be environmental contaminants. Phenyl-tris(trimethylsiloxy)silane was present in all samples analyzed, with concentrations of ~50 pg m-3 in Stockholm air and ~0.5 ng g-1 dw in sediment from the Stockholm archipelago. Tris(trifluoropropyl)trimethyl-cyclotrisiloxane and tetrakis(trifluoropropyl)tetramethyl-cyclotetrasiloxane were found in sediments from Lake Mjøsa at ~1 ng g-1 dw. The discovery of three novel environmental contaminants shows that models can be useful for prioritizing chemicals for exploratory assessment.

• Nizzetto, Pernilla Bohlin; Katsogiannis, Athanasios A.; Aas, Wenche; Breivik, Knut & Hung, Hayley (2014). Long-term trends of POPs under the European Monitoring and Evaluation Programme (EMEP) - Contribution to the global monitoring plan. Organohalogen Compounds.  ISSN 1026-4892.  76, s 538- 541
• Ratola, Nuno; Graf, Carola; Montesinos, Sonia; Garrido, Adrián; Jiménez-Guerrero, Pedro; Breivik, Knut; Lacorte, Silvia; Alves, Arminda; Sweetman, Andrew J & Jones, Kevin C (2014). Levels, spatial distribution and sources of atmospheric OCPs, PCBs and PBDEs in a Svalbard - Sao Tomé transect. Organohalogen Compounds.  ISSN 1026-4892.  76, s 1372- 1375 Full text in Research Archive.
• Chakraborty, Paromita; Zhang, Gan; Eckhardt, Sabine; Li, Jun; Breivik, Knut; Lam, Paul KS; Tanabe, Shinsuke & Jones, Kevin C (2013). Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents. Environmental Pollution.  ISSN 0269-7491.  182, s 283- 290 . doi: 10.1016/j.envpol.2013.07.032 Full text in Research Archive. Show summary

  Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Sum25PCBs in the Indian atmosphere was 4460 (+/-2200) pg m-3 with a dominance of congeners with 4-7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Sum25PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values.

• Halse, Anne Karine; Eckhardt, Sabine; Schlabach, Martin; Stohl, Andreas & Breivik, Knut (2013). Forecasting long-range atmospheric transport episodes of polychlorinated biphenyls using FLEXPART. Atmospheric Environment.  ISSN 1352-2310.  71, s 335- 339 . doi: 10.1016/j.atmosenv.2013.02.022 Full text in Research Archive. Show summary

  The analysis of concentrations of persistent organic pollutants (POPs) in ambient air is costly and can only be done for a limited number of samples. It is thus beneficial to maximize the information content of the samples analyzed via a targeted observation strategy. Using polychlorinated biphenyls (PCBs) as an example, a forecasting system to predict and evaluate long-range atmospheric transport (LRAT) episodes of POPs at a remote site in southern Norway has been developed. The system uses the Lagrangian particle transport model FLEXPART, and can be used for triggering extra (“targeted”) sampling when LRAT episodes are predicted to occur. The system was evaluated by comparing targeted samples collected over 12-25 h during individual LRAT episodes with monitoring samples regularly collected over one day per week throughout a year. Measured concentrations in all targeted samples were above the 75th percentile of the concentrations obtained from the regular monitoring program and included the highest measured values of all samples. This clearly demonstrates the success of the targeted sampling strategy.

• Kallenborn, Roland; Breivik, Knut; Eckhardt, Sabine; Lunder, Chris Rene; Manø, Stein; Schlabach, Martin & Stohl, Andreas (2013). Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica. Atmospheric Chemistry and Physics.  ISSN 1680-7316.  13, s 6983- 6992 . doi: 10.5194/acp-13-6983-2013 Full text in Research Archive.
• Krogseth, Ingjerd Sunde; Breivik, Knut; Arnot, Jon A; Wania, Frank; Borgen, Anders & Schlabach, Martin (2013). Evaluating the Environmental Fate of Short-Chain Chlorinated Paraffins (SCCPs) in the Nordic Environment Using a Dynamic Multimedia Model. Environmental Science: Processes & Impacts.  ISSN 2050-7887.  15, s 2240- 2251 . doi: 10.1039/C3EM00407D Full text in Research Archive. Show summary

  Short chain chlorinated paraffins (SCCPs) raise concerns due to their potential for persistence, bioaccumulation, long-range transport and adverse effects. An understanding of their environmental fate remains limited, partly due to the complexity of the mixture. The purpose of this study was to evaluate whether a mechanistic, integrated, dynamic environmental fate and bioaccumulation multimedia model (CoZMoMAN) can reconcile what is known about environmental emissions and human exposure of SCCPs in the Nordic environment. Realistic SCCP emission scenarios, resolved by formula group, were estimated and used to predict composition and concentrations of SCCPs in the environment and the human food chain. Emissions at the upper end of the estimated range resulted in predicted total concentrations that were often within a factor of 6 of observations. Similar model performance for a complex group of organic contaminants as for the well-known polychlorinated biphenyls strengthens the confidence in the CoZMoMAN model and implies a relatively good mechanistic understanding of the environmental fate of SCCPs. However, the degree of chlorination predicted for SCCPs in sediments, fish, and humans was higher than observed and poorly established environmental half-lives and biotransformation rate constants contributed to the uncertainties in the predicted composition and ΣSCCPs concentrations. Improving prediction of SCCPs composition will also require better constrained estimates of the composition of SCCP emissions. There is, however, also large uncertainty and lack of coherence in the existing observations, and better model-measurement agreement will require improved analytical methods and more strategic sampling. More measurements of SCCPs levels and composition in samples from background regions are particularly important.

• Krogseth, Ingjerd Sunde; Kierkegaard, Amelie; McLachlan, Michael S.; Breivik, Knut; Hansen, Kaj M. & Schlabach, Martin (2013). Occurrence and Seasonality of Cyclic Volatile Methyl Siloxanes in Arctic Air. Environmental Science and Technology.  ISSN 0013-936X.  47(1), s 502- 509 . doi: 10.1021/es3040208 Full text in Research Archive. Show summary

  Cyclic volatile methyl siloxanes (cVMS) are present in technical applications and personal care products. They are predicted to undergo long-range atmospheric transport, but measurements of cVMS in remote areas remain scarce. An active air sampling method for decamethylcyclopentasiloxane (D5) was further evaluated to include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), and dodecamethylcyclohexasiloxane (D6). Air samples were collected at the Zeppelin observatory in the remote Arctic (79° N, 12° E) with an average sampling time of 81 ± 23 h in late summer (August−October) and 25 ± 10 h in early winter (November−December) 2011. The average concentrations of D5 and D6 in late summer were 0.73 ± 0.31 and 0.23 ± 0.17 ng/m3, respectively, and 2.94 ± 0.46 and 0.45 ± 0.18 ng/m3 in early winter, respectively. Detection of D5 and D6 in the Arctic atmosphere confirms their long-range atmospheric transport. The D5 measurements agreed well with predictions from a Eulerian atmospheric chemistry−transport model, and seasonal variability was explained by the seasonality in the OH radical concentrations. These results extend our understanding of the atmospheric fate of D5 to high latitudes, but question the levels of D3 and D4 that have previously been measured at Zeppelin with passive air samplers.

• Krogseth, Ingjerd Sunde; Zhang, Xianming; Lei, Ying D.; Wania, Frank & Breivik, Knut (2013). Calibration and Application of a Passive Air Sampler (XAD-PAS) for Volatile Methyl Siloxanes. Environmental Science and Technology.  ISSN 0013-936X.  47(9), s 4463- 4470 . doi: 10.1021/es400427h Full text in Research Archive. Show summary

  Because the atmosphere is key to understanding the environmental behavior of volatile methyl siloxanes (VMS), a variety of reliable air sampling methods are needed. The purpose of this study was to calibrate and evaluate an existing, polystyrene-divinylbenzene co-polymeric resin based passive air sampler (XAD-PAS) for VMS. Sixteen XAD-PAS were deployed for 7 to 98 days at a suburban site in Toronto, Canada, while the VMS concentration in air was monitored using an active sampling method. This calibration and a subsequent field test further allowed for investigation of the temporal and spatial variability of VMS in the region. Uptake in the XAD-PAS of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and three linear VMS was linear throughout the whole deployment period. Sampling rates were between 0.4 and 0.5 m3/day. The XAD-PAS measured ∑VMS concentrations ranged from non-detects in rural areas (n = 3), to 169 ± 49 ng/m3 in the urban region (n = 21), to levels above 600 ng/m3 at sewage treatment plants (n = 2). Levels and composition of VMS within the urban area were remarkably uniform in space. Levels, but not composition, were highly variable in time and weakly correlated with temperature, wind speed and wind direction.

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• Arriola, Aline; Evenset, Anita; Krogseth, Ingjerd Sunde; Herzke, Dorte; Warner, Nicholas Alexander; Möckel, Claudia & Breivik, Knut (2019). Environmental behavior and bioaccumulation of contaminants of emerging concern in northern freshwater ecosystems.
• Krogseth, Ingjerd Sunde; Breivik, Knut & Wania, Frank (2019). Towards a temporally and spatially resolved Nested Exposure Model for organic contaminants in Arctic marine ecosystems.
• Möckel, Claudia; Eckhardt, Sabine; Krogseth, Ingjerd Sunde & Breivik, Knut (2019). Can long-range atmospheric transport events of "new" POPs to a remote site in Norway be predicted using FLEXPART?.
• Nipen, Maja; Vogt, Rolf David; Borgå, Katrine; Haarr, Ane; Mwakalapa, Eliezer Brown; Schlabach, Martin; Bohlin-Nizzetto, Pernilla; Mmochi, Aviti John & Breivik, Knut (2019). Spatial and temporal trends in e-waste related organic pollutants in a developing economy - A pilot study.
• Graf, Carola; Breivik, Knut; Jones, Kevin C & Sweetman, Andrew J (2018). Long-term trend in PCB and PBDE concentrations in ambient air: The TOMPS network and the UK-Norway transect. Show summary

  The UK Toxic Organic Micro Pollutants (TOMPs) Network, which has operated since 1991, collects ambient air samples at six urban, rural, and semi-rural sites across England and Scotland, using high-volume active air samplers [1]. Furthermore, in 1994, a latitudinal sampling transect from the south of England to the north of Norway was established with eleven sampling sites, mainly in remote locations, using Semi-Permeable Membrane Devices (SPMDs) as passive air samplers [2]. Both networks provide continuous, long-term ambient air trend data for a range of Persistent Organic Pollutants (POPs), including PCBs and PBDEs, and have helped demonstrating a decline in POPs air concentrations over the last three decades. However, in recent years no further significant declines have been observed. SumPCB and SumPBDE levels in the UK are lowest at the rural sites and highest for the urban sites (TOMPs), and they generally decrease from the south of England to the north of Norway (UK/Norway) in line with expectations. Higher values at less remote sites and sites downwind from population centres show that POPs concentrations may still mainly be influenced by primary emissions. Concentrations at semi-rural sites lie between rural and urban sites; however, they can exceed the latter in some years. This can probably be attributed to short-term local effects. The data from the TOMPs network shows that concentrations of PCBs are higher in warmer than in colder months, while the seasonal patterns are less uniform for PBDEs.

• Gusev, Alexey; Rozovskaya, Olga; Shatalov, Victor; Vulykh, Nadejda; Aas, Wenche; Breivik, Knut; Couvidat, Florian & Vivanco, M. G. (2018). Persistent organic pollutants: assessment of transboundary pollution on global, regional, and national scales. EMEP Status Report / MSC-E. 3/2018.
• Halvorsen, Helene Lunder; Möckel, Claudia; Pedersen, Lovise Skogeng; Krogseth, Ingjerd Sunde; Bohlin-Nizzetto, Pernilla; Schlabach, Martin & Breivik, Knut (2018). Passive air sampling of POPs in background air along a European-Arctic transect.
• Krogseth, Ingjerd Sunde; Bohlin-Nizzetto, Pernilla; Nøst, Therese Haugdahl & Breivik, Knut (2018). Towards an in-house Arctic environmental fate and bioaccumulation model for organic contaminants – A platform for cooperation across institutes?.
• Krogseth, Ingjerd Sunde; Breivik, Knut & Wania, Frank (2018). Development and evaluation of a bioaccumulation model for organic contaminants in European Arctic marine ecosystems.
• Krogseth, Ingjerd Sunde; Breivik, Knut & Wania, Frank (2018). Development and evaluation of a bioaccumulation model for organic contaminants in European Arctic marine ecosystems.
• Krogseth, Ingjerd Sunde; Undeman, E.; Evenset, Anita; Christensen, G. N.; Whelan, M. J.; Breivik, Knut & Warner, Nicholas Alexander (2018). Environmental fate and bioaccumulation of cVMS in a subarctic freshwater lake.
• Möckel, Claudia; Halvorsen, Helene Lunder; Pedersen, Lovise Skogeng; Krogseth, Ingjerd Sunde; Bohlin-Nizzetto, Pernilla; Borgen, Anders; Schlabach, Martin & Breivik, Knut (2018). Spatial distribution of short- and medium-chain chlorinated paraffins in European background air.
• Möckel, Claudia; Halvorsen, Helene Lunder; Pedersen, Lovise Skogeng; Krogseth, Ingjerd Sunde; Bohlin-Nizzetto, Pernilla; Borgen, Anders; Schlabach, Martin & Breivik, Knut (2018). Spatial distribution of short- and medium-chain chlorinated paraffins in European background air.
• Ratola, Nuno; Cincinelli, Alessandra; Pieri, Francesca; Montesinos, Sonia; Schuster, Jasmin K.; Katsoyiannis, Athanasios A.; Del Vento, Sabino; Graf, Carola; Moeckel, Claudia; Martellini, Tania; Breivik, Knut; Lacorte, Silvia; Jiménez-Guerrero, Pedro; Santos, Lucia; Alves, Arminda; Sweetman, Andrew J. & Jones, Kevin C. (2018). North Hemisphere air quality transects to assess legacy and emerging semivolatile organic contaminants.
• Aas, Wenche; Pran, Elise Rundén; Breivik, Knut; Sundseth, Kyrre; Høiskar, Britt Ann; Platt, Stephen Matthew; Castell, Nuria & Schlabach, Martin (2017). NILU's Strategic Institute Initiatives (SIS) 2016. NILU rapport. 12/2017. Full text in Research Archive. Show summary

  Each of NILU’s Strategic Institute Initiatives (SIS) is required to deliver a popular science report annually to the Research Council. This report contains NILU’s final reports for the SIS-projects that ended in 2016, and annual SIS-reports for 2016 for the other SIS-projects.

• Abbasi, Golnoush; Li, Li & Breivik, Knut (2017). Global and historical emission inventory of BDE-209. Show summary

  A thorough understanding of the fate of chemical in products (CiPs) within and across societies is a prerequisite to understand and predict their environmental fate. The complex processes by which chemicals are released to the environment from production, processing, use and disposal, make the tracking of CiPs in the anthroposphere a challenging task. In this study, we used a dynamic substance flow analysis model, CiP-CAFE (Chemical in Products-Comprehensive Anthropospheric Fate Estimation), to quantify the global stock and flows of BDE-209 as a chemical mixture and within products over the period of 1970 to 2050. The CiP-CAFE model divides the world into 7 regions according to regional differences in chemical industries, chemical and waste management practices as well as trade. Each region contains interconnected phases and processes which allow tracking of chemicals and quantification of stocks and flows of CiPs from one stage to the other. In this study, we used the historical production of Br and market demand of flame retardants to estimate the historical production of BDE-209. We estimated that ~1600 Kt of BDE-209 has been manufactured since 1970. Despite the discontinuation of the use of BDE-209 since 2014, our results suggest that ~400 Kt of BDE-209 is still in in-use stock globally in 2017. A total of ~1120 Kt of BDE-209 has already entered the waste stream with 52% of the total waste remains in landfills and dumping sites while the remainder of waste (48%) has been subject to irreversible waste treatment. The latter category includes inappropriate waste treatment (40%), incineration (26%), inadvertent recycling (21%) and wastewater treatment plant (13%). Global emission of BDE-209 from 1970 to 2017 was estimated to be ~80 t with 75%, 2% and 23% of the total emission released to air, water and soil, respectively. According to our estimates, more than 60% of the global emission during the production and use of BDE209-containing products occurred in more industrialized regions (North America, Europe, Japan, Australia and New Zealand), while more than 80% of emission during waste treatment and disposal of associated products occurred in less industrialized regions. This calls for further research in understating of emissions of harmful chemicals from throughout their entire life-cycles. The CiP-CAFE model provides a comprehensive analysis of the stock, flows and emissions of harmful chemicals that can be used as valuable tool to devise more effective chemical management plans in order to protect the environment and human health at the global scale.

• Breivik, Knut (2017). Development, evaluation and application of a nested exposure assessment model for organic contaminants in the Nordic and Arctic region (NEM)..
• Breivik, Knut (2017). Nye organiske miljøgifter som spres via luft i økosystemer i nord.
• Breivik, Knut (2017). Stationary sampling of ambient air in Europe - in the context of human exposure of chemicals through the environment. Show summary

  Beyond direct inhalation, the atmosphere has been shown to represent a key pathway for chemical entry via other parts of the physical environment as well as the human food-chain. Air monitoring data is therefore important for a complete understanding of human exposure to airborne chemicals. Such data are furthermore required for attempts to understand and evaluate relationships between emission sources and atmospheric concentrations - and thereby an integrated aspect of overall source-exposure relationships. In this talk, an introduction to existing databases on chemicals in ambient air will be given. The focus will highlight monitoring data and databases for selected persistent organic pollutants (POPs) and heavy metals in European background air. Using organic contaminants as examples, the merit and limitations of different techniques to measure spatial and temporal trends of chemicals in air and deposition will be discussed in terms of exposure relevance. Finally, opportunities of combining air monitoring data with exposure models to understand and predict human exposure via the environment will be assessed.

• Breivik, Knut; MacLeod, Matthew; Wania, Frank & Eckhardt, Sabine (2017). Towards a Nested Exposure Model for organic contaminants (NEM).
• Breivik, Knut; MacLeod, Matthew; Wania, Frank & Eckhardt, Sabine (2017). Towards a nested multimedia fate, transport and bioaccumulation model for the Nordic region. Show summary

  Most empirical monitoring programs on organic contaminants, including POPs, typically target a specific area, country or region. The Nordic region, including remote Arctic areas such as Svalbard, is probably among the more well studied regions with respect to the empirical occurrence of organic contaminants within various ecosystems. Yet, gaps remain in our understanding of the link between sources and exposures in this region, including how source-exposure relationships may vary in space and time, for individual contaminants and across abiotic and biotic compartments. As POPs are global pollutants, sources affecting Nordic regions could both be distant and/or of more local origin. Furthermore, the persistence of POPs implies that current exposures could be a result of both historical as well as recent emissions. This calls for regional modelling strategies which are global in context yet dynamic, reflecting both the possible mobility and life-time of relevant contaminants. Here, we introduce the first version of an integrated fate, transport and exposure model for the Nordic region (Nordic Exposure Model - NEM). The point of departure for NEM are three existing models, notably BETR-Global, ACC-Human and CoZMo-POP2. In contrast to these models, theNEM model reflects the hypothesis that accurate predictions of organic contaminant exposures call for increasing resolution with increasing proximity (in space and time) to a study region of interest. Hence, NEM is being developed as a nested model, consisting of (up to) five different gridded model domains, simulated in sequence: Global (30ºx120º Lat/Long) > Northern Hemisphere (30ºx30º) > Europe (15ºx15º) > Northern Europe (7.5ºx7.5º) > Nordic region (3.75ºx3.75º). Chemical transport between neighbouring grid cells may occur by air, fresh water and seawater. Chemical inflow from the outside world and into a given domain (except the initial global domain), is based on simulations of the preceding domain. The physical environment within a given grid cell within NEM includes up to 10 different compartments (upper and lower atmosphere, broadleaf and needleleaf canopies, forest soil, uncultivated soil, agricultural soil, fresh water, fresh water sediment and marine water). The NEM model also includes the opportunity to simulate bioaccumulation in the human food-chain within a user-defined grid cell, allowing relationships between sources and biotic exposures in a specific receptor to be evaluated. Here, an overview of the initial version of NEM will be given, along with initial results using PCBs (polychlorinated biphenyls) as an example. Plans for further development, evaluation and opportunities for future applications will be presented.

• Graf, Carola; Breivik, Knut; Jones, Kevin C & Sweetman, Andrew J (2017). Investigating Long-term Trends in PCB Concentrations in Ambient Air: The TOMPs Network and the UK-Norway Transect. Show summary

  Polychlorinated Biphenyls (PCBs) were first synthesised in 1881, but their commercial production only began in 1929 in the USA. They were marketed under various trade names depending on the country where they were produced such as Aroclor (Monosanto, USA) and Clophen (Bayer, Europe). Because of high chemical and thermal stability, electrical resistance, and low or no flammability, PCBs had extensive applications. They were used as dielectric fluids in capacitors and transformers, in plasticisers, adhesives, inks, sealants and surface coatings. Production of PCBs peaked in the 1960s in Europe and USA; they were ultimately banned in the late 1970s / early 1980s. Before the ban, PCBs entered the environment through point and diffusive sources such as landfill sites, accidental releases/spillages via leakage during commercial use of electrical equipment and transformer and capacitor fires, or incineration of PCB waste. Current atmospheric levels of PCBs in the environment can be accounted for by ongoing primary anthropogenic emissions (e.g. accidental release of products or materials containing PCBs), volatilisation from environmental reservoirs (e.g. oceans and soils) which have previously received PCBs (secondary emissions), or incidental formation during combustion processes. The UK Toxic Organic Micro Pollutants (TOMPs) Network, which has operated since 1991, collects ambient air samples at six sites across England and Scotland, using high-volume active air samplers. The network provides long-term ambient air trend data for a range of Persistent Organic Pollutants (POPs), including PCBs, at both urban and rural locations, and thus allows detailed studies on atmospheric fate and behaviour processes of persistent chemicals. It has played an important role in the successful understanding and modelling of their environmental sources and fate. The continuous monitoring of PCBs for the TOMPs programme has demonstrated the constant decline in their UK air concentrations over the last decades. The concentrations of all congeners are generally significantly higher at urban compared to semi-rural and rural sites. The PCB fingerprint (relative concentrations) in TOMPs samples has not changed over time, which indicates that primary diffusive sources in urban areas are still dominant and probably the controlling factor of trends in the UK ambient air PCB concentrations.In 1994, a latitudinal sampling transect from the south of England to the north of Norway was established with eleven sampling sites, mainly in remote locations, using Semi-Permeable Membrane Devices (SPMDs) as passive air samplers. The aim of this transect was to investigate spatial and temporal trends of POPs concentrations, and in particular to test the hypotheses of global distillation and fractionation. Since 1994, the UK/Norway SPMD transect has produced ten two-year samples (except 1996 – 1998) at each site. Results show that PCB concentrations have generally decreased from the south to the north of the transect, as well as over time. They have, however, levelled off in recent years, which may be explained by increasing importance of secondary emissions.

• Halse, Anne Karine; Schlabach, Martin; Schuster, Jasmin K.; Jones, Kevin C.; Steinnes, Eiliv & Breivik, Knut (2017). Corrigendum to “Endosulfan, pentachlorobenzene and short-chain chlorinated paraffins in background soils from Western Europe” (Environmental Pollution (2015) 196 (21–28) (S0269749114003893) (10.1016/j.envpol.2014.09.009)). Environmental Pollution.  ISSN 0269-7491.  220, s 1477- 1479 . doi: 10.1016/j.envpol.2016.10.084
• Krogseth, Ingjerd Sunde; Breivik, Knut & Nøst, Therese Haugdahl (2017). Towards an “in-house” Arctic bioaccumulation model for organic contaminants. A platform for cooperation across institutes?.
• Krogseth, Ingjerd Sunde; Undeman, Emma; Evenset, Anita; Christensen, Guttorm N; Whelan, Mick; Breivik, Knut & Warner, Nicholas Alexander (2017). Factors affecting bioaccumulation of cyclic volatile methyl siloxanes in a sub-arctic bentho-pelagic food web. Show summary

  Cyclic volatile methylsiloxanes (cVMS) are used in personal care products and are emitted to aquatic environments through wastewater effluents. Due to the high hydrophobicity of cVMS, sediments are expected to be an important source for exposure in benthic and bentho-pelagic food webs. However, details of exposure pathways have yet to be fully understood. The main objective of this study was to evaluate the role of sediments in the bioaccumulation of cVMS in Nordic environments, using a north-Norwegian lake (Lake Storvannet) as a case-study. Concentrations of cVMS were measured in benthos (chironomid larvae and the pea clam Pisidium sp.) and fish (three-spined sticklebacks [Gasterosteus aculeatus], Arctic char [Salvelinus alpinus], and brown trout [Salmo trutta]) from the lake. Existing measurements of polychlorinated biphenyls (PCBs 101, 118, 138, 153, 180) were used to evaluate a new bentho-pelagic version of the bioaccumulation model ACC-HUMAN (including a benthic filter feeder and a benthic predator/deposit feeder). The model predictions of PCB concentrations in char and trout were in better agreement with measurements (predictions were within a factor of 4 to measured concentrations) compared to predictions with the pelagic-only model (factor of 8 between predictions and measurements). Predictions improved most for char, which feed mainly on benthos in this lake. This suggests that the bentho-pelagic model is a better representation of the Storvannet ecosystem than the pelagic-only model. The model was next applied to evaluate the fate of cVMS in the Storvannet food web. Decamethylcyclopentasiloxane (D5) was the dominant cVMS congener in the lake, with measured concentrations of 2.0 ± 0.04, 17.8 ± 0.7, 3.2 ± 2.3, 3.8 ± 2.8, and 0.8 ± 0.6 μg/g lipid in chironomid larvae, Pisidium sp., sticklebacks, char, and trout, respectively. Concentrations were lower, and sometimes below limits of quantification, for octamethylcyclotetrasiloxane (D4) and dodecamethylcyclohexasiloxane (D6). Predicted cVMS concentrations in benthos were underestimated compared to measurements (ratio of 0.04 to 0.4 between predictions and measurements), while predicted cVMS concentrations in fish were in good agreement with measurements (ratio of 0.5 to 2.5). Model predictions were highly sensitive to the partition coefficients between organic carbon and water (KOC) and its temperature dependence. This is because the model predicts benthic organisms to be the main source of cVMS for fish, and KOC controls bioavailability of cVMS for benthos in the model. The model furthermore predicted considerable losses of cVMS through ventilation for fish, resulting from higher fugacity in the benthic-feeding fish than in lake water. As a result, model predictions were relatively insensitive to the biotransformation rate constants in fish.

• Krogseth, Ingjerd Sunde; Undeman, Emma; Evenset, Anita; Christensen, Guttorm N; Whelan, Mick; Breivik, Knut & Warner, Nick A. (2017). Factors affecting bioaccumulation of cyclic volatile methyl siloxanes in a subarctic benthopelagic food web. Show summary

  Cyclic volatile methylsiloxanes (cVMS) are used in personal care products and are emitted to aquatic environments through wastewater effluents. Due to the high hydrophobicity of cVMS, sediments are expected to be an important source for exposure in benthic and benthopelagic food webs. However, details of exposure pathways have yet to be fully understood. The main objective of this study was to evaluate the role of sediments in the bioaccumulation of cVMS, using a north-Norwegian lake (Lake Storvannet, 70 °N, 23 °E) as a case-study. Concentrations of cVMS were measured in benthos (chironomid larvae and the pea clam Pisidium sp.) and fish (three-spined sticklebacks (Gasterosteus aculeatus), arctic char (Salvelinus alpinus), and brown trout (Salmo trutta)), while existing measurements of polychlorinated biphenyls (PCBs 101, 138, 153) were used to evaluate a new benthopelagic model. The aquatic module of the bioaccumulation model ACC-HUMAN was expanded to include a benthic filter feeder and a benthic predator/deposit feeder, and the model was parameterized for Storvannet. The pelagic version of the model over-predicted PCB concentrations in char and trout by factors of 3 to 16 compared to measurements (ratio between median values), and the benthopelagic model by factors of 2 to 7. Inclusion of the benthic link, therefore, improved predictions, particularly for char that feed mainly on benthos in this lake. D5 was the dominant cVMS congener in the lake, with measured concentrations of 2.0 ± 0.04, 17.8 ± 0.7, 3.2 ± 2.3, 3.8 ± 2.8, and 0.8 ± 0.6 μg/g lipid in chironomid larvae, Pisidium sp., three-spined sticklebacks, char, and trout, respectively. The benthopelagic model over-predicted cVMS concentrations in all species, but reproduced well the relationships between the different species. As Storvannet has temperatures around 0 °C for the majority of the year, the differing temperature-dependency of partitioning between organic phases and water for PCBs and cVMS was important for the model predictions. This was particularly pronounced in the benthic linkages within the model, where several differences in bioaccumulation behavior between PCBs and cVMS was observed. This highlights the need to increase the understanding of partitioning of cVMS at low temperatures. Also, it stresses the importance of understanding bioaccumulation behavior and biotransformation capacities in lower trophic levels, which are fundamental to understand also the higher trophic levels.

• Nøst, Therese Haugdahl; Halse, Anne Karine; Schlabach, Martin; Bäcklund, Are; Eckhardt, Sabine & Breivik, Knut (2017). Low concentrations of persistent organic pollutants (POPs) in air at Cape Verde.
• Nøst, Therese Haugdahl; Sandanger, Torkjel M; Nieboer, Evert; Odland, Jon Øyvind & Breivik, Knut (2017). Delayed emissions of POPs from transboundary waste streams may cause spatially and temporally divergent monitoring trends.. Show summary

  Time trends in human concentrations of select persistent organic pollutants (POPs) during 1979-2007 in five repeated blood samples from 53 men in Northern Norway demonstrated clear relations between and environmental emissions. Despite considerable declines for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) since 1986, the sum of the 49 targeted POPs increased from 1979 until 2001, with per- and polyfluorinated alkyl substances (PFASs) dominating recent blood burden measurements. Specifically, the time trends in serum concentrations of POPs, exemplified by PCB- 153, 1,1′-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene) (DDT) and perfluorooctane sulfonic acid (PFOS), resembled the trends in available data on their emissions, production or use. Further, emission-based mechanistic modelling, exemplified by PCBs, provided estimated blood concentrations that agreed well with the time trends observed. Our results suggest that interpretations of human biomonitoring trends for POPs should consider historic emissions. Although emissions are low in many countries compared to those in the past, many industrial POPs remain in products and waste streams even today due to the long life-time of products containing these compounds. As some of this waste is exported across country borders, this causes delayed emissions which may again cause divergent spatial and temporal trends among various monitoring studies. One example is the elevated emissions from informal waste or recycling processes in developing regions, such as of PCBs and other organic contaminants released from waste electrical and electronic equipment. Indeed, elevated concentrations of legacy POPs in humans in areas influenced by such activities have been reported. Thus, although temporal trends of the legacy POPs clearly indicate reduced human exposure to these compounds in industrialized countries, the trends in developing countries do not necessarily conform. Comparisons of the PCB concentrations from Norway, a country with no past production of PCBs and that banned new use in 1980, to available monitoring results from selected areas known to be affected by informal waste and/or recycling processes underlined that human time trends may be spatially variable across the globe, which in this specific case was likely attributed to elevated emissions from contaminants in transboundary waste streams. Clearly, knowledge of temporal and spatial differences in emissions of POPs from waste streams could guide the design and interpretation of biomonitoring studies in populations experiencing possible significant time-lags in human exposure to legacy POPs.

• Vee, Marthe; Eriksen, Freja; Sørbye, Ida Eri & Breivik, Knut (2017, 01. april). Søppelgruven. [Tidsskrift].  Aftenposten Innsikt. Show summary

  Elektronisk avfall blir stjålet fra norske elektronikkbutikker, smuglet over grensen og sendt til land der brukt elektronikk er luksusvarer. Norsk søpper er en del av en global milliardindustri.

• Aas, Wenche; Breivik, Knut; Fiebig, Markus; Høiskar, Britt Ann Kåstad; Pacyna, Elisabeth G; Runden, Elise; Schlabach, Martin & Sundseth, Kyrre (2016). NILU's Strategic Institute Initiatives (SIS) 2015.. NILU rapport. 3/2016. Full text in Research Archive.
• Abbasi, Golnoush & Breivik, Knut (2016). Global Historical Inventory of PBDEs: From Production and Consumption Towards Emissions..
• Breivik, Knut; Krogseth, Ingjerd Sunde & Lindquist, Andrea (2016, 07. august). UFO-er kartlegger miljøgifter. [Internett].  NRK.
• Colette, Augustin; Aas, Wenche; Banin, Lindsay; Braban, Christine F.; Ferm, Martin; Ortiz, Alberto; Ilyin, I.; Mar, Kathleen; Pandolfi, Marco; Putaud, Jean-Philippe; Shatalov, Victor; Solberg, Sverre; Spindler, Gerald; Tarasova, Oksana; Vána, Milan; Adani, Mario; Almodovar, Paul; Berton, Eva; Bessagnet, Bertrand; Bohlin-Nizzetto, Pernilla; Borukova, Jana; Breivik, Knut; Briganti, Gino; Cappelletti, Andrea; Cuvelier, Kees; Derwent, Richard; D'Isidoro, Massimo; Fagerli, Hilde; Funk, Clara; Vivanco, Marta García; Haeuber, Richard; Hueglin, Christoph; Jenkins, Scott; Kerr, Jennifer; de Leeuw, Frank; Lynch, Jason; Manders, Astrid; Mircea, Mihaela; Pay, María Teresa; Pritula, Dominique; Querol, Xavier; Raffort, Valentin; Reiss, Ilze; Roustan, Yelva; Sauvage, Stéphane; Scavo, Kimber; Simpson, David; Smith, Ron I.; Tang, Y. Sim; Theobald, Mark; Tørseth, Kjetil; Tsyro, Svetlana G.; van Pul, Addo; Vidic, Sonja; Wallasch, Markus & Wind, Peter (2016). Air pollution trends in the EMEP region between 1990 and 2012. Joint Report of the EMEP Task Force on Measurements and Modelling (TFMM), Chemical Co-ordinating Centre (CCC), Meteorological Synthesizing Centre-East (MSC-E), Meteorological Synthesizing Centre-West (MSC-W).. EMEP/CCC-Report. 1/2016. Full text in Research Archive.
• Graf, Carola; Breivik, Knut; Jones, Kevin C & Sweetman, Andrew J (2016). The UK/Norway-Transect Investigating spatial and temporal trends for POPs..
• Nøst, Therese Haugdahl; Bäcklund, Are; Eckhardt, Sabine; Halse, Anne Karine; Schlabach, Martin & Breivik, Knut (2016). Monitoring and modelling of POPs in air at Cape Verde, Africa. Show summary

  Ambient air is among the core media selected for the sampling and analysis of Persistent Organic Pollutants (POPs) under the Stockholm Convention. Ambient air also provide useful information for (i) studies of global transports of POPs, and (ii) atmospheric sources and source regions. Yet, existing data on POPs in air based on active air sampling remain scarce and mainly limited to industrialized regions in the northern hemisphere. The primary objectives of this study were to (i) monitor concentrations of selected POPs in air outside West Africa, and (ii) to evaluate sources and source regions affecting measured concentrations. For this purpose, an active high-volume air sampler was installed on The Cape Verde Atmospheric Observatory (CVAO: 16.848°N, 24.871°W), a World Meteorological Organization (WMO) global station at Cape Verde outside the coast of West Africa. Sampling commenced in May, 2012 and 43 samples were collected until June 2013 (24 h sampling). The samples were analyzed for selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorbenzene (HCB) and chlordanes. The source regions of the air masses were evaluated for each sample using the FLEXPART model. FLEXPART is an atmospheric Lagrangian transport model, developed by Andreas Stohl and co-workers, which calculates the trajectories of so-called tracer particles (flexpart.eu). It was run in backward mode, in order to identify the source regions of air pollutants at a particular site. A general finding is that the concentrations measured are in the lower range in comparison to data from the literature, which is mainly attributed to the remoteness of the station from major sources and source regions. Factors controlling measured concentrations will be evaluated and discussed.

• Nøst, Therese Haugdahl; Rylander, Charlotta; Lund, Eiliv; Sandanger, Torkjel M & Breivik, Knut (2016). Estimating time-varying PCB exposures using person-specific predictions to supplement measured values: Evaluation of agreement and application in health effect study.
• Breivik, Knut (2015, 19. mars). Intervjuet om industrielle miljøgifter i avfall og eksport til fattige land i Schrödingers katt. [TV].  NRK.
• Breivik, Knut; Armitage, James M; Wania, Frank; Sweetman, Andrew J & Jones, Kevin C (2015). Assessing the implications of export of waste electrical and electronic equipment (WEEE) towards developing regions: PCBs as a case study. Show summary

  Densely populated areas (i.e., urban centres) are largely responsible for the generation of waste electrical and Electronic equipment (WEEE/e-waste) in both industrialized and developing nations. The potential emission of both emerging and Legacy contaminants present in WEEE (e.g., organic chemicals, metals) during handling and disposal of these products is a concern with impacts at local to global scale. Over the last decade, a number of studies have reported surprisingly high levels of polychlorinated biphenyls (PCBs) within or outside developing regions in Asia and West Africa. As PCBs were never extensively produced nor used in these regions, this previously led us to hypothesize that there might be a potential shift in global source regions, attributed to exports of wastes containing PCBs towards developing regions. If true, it follows that global emissions, transport and exposures can neither be completely estimated, nor fully rationalized, without considering emissions caused by the global flows of relevant wastes. In this study, we have therefore updated an existing global historical PCB emission inventory to account for exports of wastes, using global flows of e-waste as a proxy for wastes containing PCBs. Our revised emission scenarios indicate that (i) global emissions may significantly increase as result of exports of wastes in comparison to reference scenario (i.e. no exports) and (ii) different long-term temporal trends in emissions within former production and use regions versus developing regions implicated as importers of wastes are expected. The second goal of this study is to simulate the global fate and transport of PCBs using emission scenarios that include potential contributions linked to the export of e-waste and compare model output to the baseline scenario (no export). To accomplish this task, we use the BETR Global 2.0 model, a publicly available fate/transport model, which represents the globe as 288 interconnected, multi-compartment zones at a spatial resolution of 15 x 15 degrees. Simulations are conducted for the period 1930–2100 and output from various locations and time periods are interpreted in the context of available monitoring data. Model output is also used to assess the potential implications of transboundary movement of wastes containing PCBs for human exposure in developing regions. However, significant uncertainties in these global emission scenarios still persist.

• Breivik, Knut; Halse, Anne Karine; Schlabach, Martin; Sweetman, Andrew J & Jones, Kevin C (2015). Organiske miljøgifter i luft i norske kystsoner med kostholdsråd på sjømat: Langtransport, lokale utslipp eller gamle synder?. Show summary

  Et karakteristisk trekk ved oppførselen til mange organiske miljøgifter er deres utstrakte potensiale til å vandre mellom ulike medier, så som sedimenter, vann, jord og luft. Dette innebærer at kontrollstrategier rettet mot en av disse medier alene ikke nødvendigvis vil gi en reduksjon i den totale miljøgiftbelastningen. I flere norske kystsoner er det kostholdsråd på sjømat grunnet forhøyede forekomster av ulike organiske miljøgifter. Men effekten av en eventuell opprydding på sjøbunnen vil eksempelvis avhenge av at man har fått kontroll over aktive tilførsler fra land og luft. I dette forskningsprosjektet har vi studert forekomst og tilførsler av organiske miljøgifter i luft i kystsoner med kostholdsråd på basis av passive luftprøvetakere. Et viktig delmål har vært å vurdere om forekomst primært kan forklares med gjenværende lokale utslipp til luft eller atmosfærisk langtransport? Målekampanjen i 22 utvalgte kystsoner med kostholdsråd på sjømat ble derfor koordinert samtidig som en større kampanje for å vurdere bakgrunnsbelastningen i 34 Europeiske land (N=86) og da med særlig fokus på Norden. Resultatene fra belastede kystsoner kan dermed benyttes til å evaluere hvorvidt nivåene i norske kystsoner primært tilskrives langtransport eller lokale kilder. Viktige funn var at (1) Konsentrasjoner av PCB (polyklorerte bifenyler) var typisk lokalt forhøyet i bynære områder og opp til ~10 ganger høyere enn forventet på basis av langtransport alene. (2) HCB (heksaklorbensen) og PAH (polysykliske aromatiske hydrokarboner) var typisk sporadisk forhøyet i kystsoner med tidligere eller pågående industrielle aktivitet. (3) En urban lokalitet i Bergen var sterkt påvirket av forbudte insektmidler (Teknisk DDT og Lindan) (4) a-HCH (en viktig bestanddel i tekniske blandinger av insektmiddelet heksaklorosykloheksan) var gjennomgående forhøyet i kystsonene, noe som tilskrives avdamping fra havet («gamle synder»). Selv om forekomst av miljøgifter i norske kystsoner ofte var påvirket av lokale kilder, er det fortsatt behov for å øke forståelse av hvorvidt miljøgiftbelastningen primært skyldes gamle eller nye synder. Uten denne kunnskapen kan for eksempel kontrollstrategier rettet mot sedimenter alene vise seg å gi en svært begrenset miljøgevinst.

• Krogseth, Ingjerd Sunde; Warner, Nicholas Alexander; Christensen, Guttorm N.; Whelan, Mick; Breivik, Knut; Evenset, Anita & Wasbotten, Ingar Halvorsen (2015). Understanding the fate and bioaccumulation of cyclic volatile methyl siloxanes in an Arctic lake. Show summary

  Cyclic volatile methyl siloxanes (cVMS) are used in personal care products and are emitted to aquatic environments through wastewater effluents. Once present in aquatic environments, they can undergo volatilization, hydrolysis or sedimentation. In ice-covered lakes, volatilization of cVMS may be limited and rates of hydrolysis may be slowed down due to low temperatures. This could potentially increase the persistence of cVMS in these systems and hence increase exposure to aquatic organisms. The main objective of this study was to develop a holistic and mechanistic understanding of cVMS behavior by combining multimedia modeling and monitoring for an Arctic lake receiving unintentional wastewater emissions. The dynamic QWASI model and the aquatic module of the ACC-HUMAN model were used to predict the seasonality of cVMS concentrations in Lake Storvannet in Hammerfest, Norway (70 °N, 23 °E). This lake receives sewage emissions from both leaking pipes and sewer overflow events, and is ice covered for approximately 6 months of the year. Lake water, surface sediments, one sediment core, Arctic char (Salvelinus alpinus) and Brown trout (Salmo trutta) from the lake, as well as nearby river water and wastewater were sampled in March and June of 2014. In addition, marine water, surface sediments, and Atlantic cod (Gadus morhua) were sampled from the nearby marine harbor, where the main municipal sewage outlet is currently located. Samples were analyzed for cVMS using established analytical methods. cVMS were detected in sewage, but were below limits of quantification in lake, river, and marine water. However, cVMS were detected in lake and marine surface sediments, and in deeper sediments deposited up to 30 years ago illustrating the persistence of these compounds. cVMS were also measured in liver tissue from both Brown trout, Arctic Char and Atlantic Cod with large variations between individual fish. The cVMS concentrations in freshwater fish are likely to be enhanced through benthic exposure, stressing the importance of the sediment compartment not only for persistence but also for bioaccumulation of cVMS. Temporal variations of cVMS concentrations in Storvannet will be driven by a combination of variable emissions and seasonality in environmental conditions, which will be further investigated through model simulations.

• Lopez-Aparicio, Susana; Myhre, Cathrine Lund; Fiebig, Markus; Schlabach, Martin; Aas, Wenche; Breivik, Knut & Runden, Elise (2015). NILU’s Strategic Institute Initiatives (SIS) - 2014. NILU OR (NILU Oppdragsrapport). 8/2015. Full text in Research Archive. Show summary

  Each of NILU’s Strategic Institute Initiatives (SIS) is required to deliver a popular science report annually to the Research Council. This report contains all of NILU’s annual SIS-reports for 2014

• Nøst, Therese Haugdahl; Randall, Scott; Schlabach, Martin; Paul, Alak; Rahman, Atiqur & Breivik, Knut (2015). Concentrations in air and potential emission sources of POPs in Chittagong, Bangladesh. Show summary

  At present there is limited information on concentrations of POPs (persistent organic pollutants) in air in many developing regions compared to those of industrialized countries. However, several studies have demonstrated surprisingly high levels of various legacy POPs in some developing countries, e.g. because of continued use of organochlorine pesticides or emissions of industrial-use POPs from informal recycling and disposal of e-waste (Electrical and Electronic waste). However, the potential emissions of POPs from informal shipbreaking activities in developing regions remains to be assessed. Global estimates for 2012 reveal that 1,250 ocean ships were scrapped in this year alone, and the beaches on the Chittagong coast in Bangladesh is one of the areas of most intense ship breaking in the world. The shipbreaking activities in this area have caused concern for both environmental and human health because of various contaminants released from - or emitted as a result of – these activities. The aim of the study was to monitor the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides in air in the urban environment of Chittagong city (population approximately 4 million) and in vicinity of the ship-breaking areas. A sampling campaign was carried out using passive air samplers (PASs) based on polyurethane foam (PUF) at 23 sites in February 2013. PUF was selected as sampling material because their performance is well characterized as they have previously been used extensively for spatial mapping on both a regional and global scale. Performance Reference compounds (PRCs) were furthermore used for back-calculating air concentrations. The results from the campaign in Chittagong will be compared and contrasted with concentrations of POPs in air reported from both developed and developing regions, and to discuss potential sources and source regions controlling the atmospheric burden of various POPs in the study area.

• Nøst, Therese Haugdahl; Sandanger, Torkjel M; Odland, Jon Øyvind & Breivik, Knut (2015). The dynamics of the human contaminants cocktail: Employing longitudinal POPs data from Northern Norway (1979-2007) and mechanistic models. Show summary

  Humans are continuously exposed to a substantial number of contaminants, and no study can capture the overall complexity. The present work has summarized the time trends across almost thirty years for 24 polychlorinated biphenyls (PCBs), 17 organochlorine pesticides including metabolites (OCPs), 3 polybrominated diphenyl ethers (PBDEs), and 10 per- and polyfluoroalkyl substances (PFASs) in a set of persons. These trends were based on analyses of serum sampled from 53 men in Northern Norway in 1979, 1986, 1994, 2001, and 2007. DDTs decreased from 1979, many PCBs from 1986 whereas PBDEs were low throughout and PFASs increased until 2001 and decreased thereafter. The compositional patterns changed according to the trends yet PFASs were dominant in most years. Based on these results, the understanding of temporal aspects of human concentrations can provide a holistic view on human exposure to contaminants in terms of complexity and dynamics. A close resemblance could be observed between human concentrations and the overall global emission estimates for the different compound groups. Also, emission-based environmental and human accumulation modeling could reproduce temporal trends for PCBs and the age group patterns observed in measurements. Predicting individual PCB concentrations in two cross-sectional studies including pregnant and postmenopausal women displayed realistic concentrations compared to measurements. Predicting concentrations previous in their life course revealed temporal aspects providing valuable illustrations of variation over time in PCB concentrations within and between individuals. In the longitudinal study, the time trends were specific to the different compound groups and the diverging changes likely largely relate to different production and use histories along with environmental and human persistence. These perspectives clearly show the close relation between use and concentrations and have implications for considerations of human exposure.

• Wania, Frank; Matt J., Binnington; Wood, Stephen A.; Armitage, James M; Nøst, Therese Haugdahl & Breivik, Knut (2015). Modeling the exposure history of human individuals to persistent organic pollutants. Show summary

  Combined environmental fate and food chain bioaccumulation models provide the capability to simulate, through a fully mechanistic description of the relevant thermodynamic and kinetic processes, a persistent organic pollutant (POP)’s journey from release into the environment to its accumulation in humans. Non-steady-state models allowing time-variant simulations covering periods of multiple decades have been used to estimate the average exposure history of different population cohorts to POPs. Such assessments may then serve as a complement to empirical biomonitoring studies evaluating a population's exposure to POPs. It is of substantial interest to identify sources of variability in the measured human concentrations. Biomonitoring studies often obtain additional information on the sampled individuals through questionnaires. Collected data generally include age at sampling, date of sampling, gender, body mass index, number of children and age at birth, breastfeeding habits, and detailed dietary composition. While such data can be used to find statistical associations between measured contaminant exposures and potential influential factors, Statistical analyses cannot identify causal relationships and provide ultimately no mechanistic understanding of the processes underlying human POP exposure. However, the same questionnaire responses can also be used to individualize the parameterization of the human in mechanistic exposure models. In other words, instead of only calculating average population exposure, the models can be used to simulate the distinct exposure histories of all sampled human participants individually. Here we present the results of three studies simulating the exposure of individuals to polychlorinated biphenyls (PCBs) using the environmental fate and bioaccumulation model CoZMoMan or similar model combinations. The models generally succeed in predicting population average exposure. Also the range of predicted PCB exposures generally agrees with the range of measured exposures. Trends with key variables, such as BMI and age, were mostly similar for the measured and simulated concentration data. However, in two studies the models attributed more of the variability in PCB exposure to interindividual differences in dietary composition than a statistical analysis of the measured data would support. The measured data indicated that there were other sources of variability not currently accounted for in the models.

• Armitage, James M; Wania, Frank & Breivik, Knut (2014). Long-range transport of e-waste: Part 2. Exploring the potential implications of trans-boundary e-waste exports on chemical emissions, fate and exposures. Show summary

  Trans-boundary movement of e-waste and the associated contaminants (e.g., polychlorinated biphenyls, halogenated flame retardants, metals) has emerged as an important research topic in the last decade. Several monitoring studies published in the peer-reviewed literature have documented elevated levels of various industrial-use organic contaminants (IUOCs) in the atmosphere near known or suspected e-waste receiving and processing sites in Asia. Surprisingly high concentrations of polychlorinated biphenyls in the atmosphere were also reported offshore of West Africa. Emissions of IUOCs linked to trans-boundary movement of e-waste have implications for chemical fate and exposure at local, regional and global scale. For example, the transfer of e-waste from temperate climates to tropical regions could lead to enhanced emissions simply through temperature-related increases in passive volatilization from open landfill sites. The main objective of this study is to develop emission scenarios for selected IUOCs considering the generation and transport of e-waste and simulate and compare chemical fate and transport using an evaluative modeling approach. All simulations were conducted using BETR-Global 2.0 (https://sites.google.com/site/betrglobal/), a chemical fate model which divides the globe into 288 zones (15o x 15o). This spatial resolution is deemed suitable for assessments at the regional as well as global scale. Breivik et al. (SETAC 2014) present an inventory of the global generation and trans-boundary exports of e-waste towards non-OECD countries, with an emphasis on locations in sub-tropical and tropical regions. This inventory along with the physical-chemical property data of selected IUOCs (e.g., partition coefficients, degradation rate constants) are the key inputs to the model simulations. Model output under various emission scenarios are compared in terms of overall persistence (POV) at the global scale as well as in terms of long-range transport potential (LTRP) at regional and global scale (e.g., atmospheric deposition of IUOCs in remote regions). The model outputs are also used to assess the potential implications for chemical exposure at regional and global scale under the various scenarios.

• Armitage, James M; Wania, Frank & Breivik, Knut (2014). Simulating the potential implications of transboundary waste exports on the fate and exposure to PCBs. Show summary

  Polychlorinated biphenyls (PCBs) are one of the few classes of chemicals for which relatively detailed information on production, use and emissions is available. The physical-chemical properties of these compounds are also reasonably well-characterized. Using these input data, the fate/transport and human exposure to these contaminants has been simulated at various spatial and temporal resolutions and compared to available monitoring data. While good agreement between model output and monitoring data is frequently observed, there are some notable exceptions. Of particular interest is the number of monitoring studies reporting surprisingly high levels of PCBs within or in proximity to developing nations in West Africa and South Asia. These observations led to the hypothesis that a substantial shift in PCB emissions has occurred recently, attributable to the export of wastes containing PCBs from developed countries (i.e., main historic source regions) to developing regions. Based on this hypothesis, existing historic PCB emission inventories were updated by Breivik et al. (SETAC Vancouver) using global flows of e-waste as a proxy for transboundary movement of wastes containing PCBs. The purpose of this study is to simulate and compare the global fate and transport of PCBs using the original and revised emission inventories in order to assess the potential significance of these waste exports at regional and global scales. To accomplish this task, we use the BETR Global 2.0 model, a publicly available fate/transport model which represents the globe as 288 interconnected, multi-compartment zones at a spatial resolution of 15 x 15 degrees. Simulations are conducted for the period 1930–2100 and output from various locations and time periods are interpreted in the context of available monitoring data. Model output is also used to characterize the potential implications of transboundary movement of wastes containing PCBs for human exposure in countries currently receiving these products.

• Breivik, Knut (2014). Langtransport av miljøgifter med avfall: En giftfri framtid på bekostning av fattige land?.
• Breivik, Knut; Armitage, James M; Sweetman, Andrew J & Jones, Kevin C (2014). Exploring the possible implications of exports of waste towards developing regions for global emissions of PCBs. Show summary

  The global production of polychlorinated biphenyls (PCBs) peaked more than 40 years ago and ceased when the last factories closed in Russia in 1993. Yet, PCBs continue to be omnipresent in the global environment. While this is partly caused by their environmental persistence, another key aspect is that most PCBs were used in closed applications with long use-life expectancies (e.g., capacitors, transformers), which may cause significant delays between production/use and primary emissions. Over the last decade, a number of studies have reported surprisingly high levels of PCBs within or outside developing regions in Asia and West Africa. As PCBs were never extensively produced nor used in these regions, this previously led us to hypothesize that there might be a potential shift in global source regions, attributed to exports of wastes containing PCBs towards developing regions. If true, it follows that global emissions cannot be completely estimated, nor fully rationalized, without considering emissions caused by the global flows of relevant wastes. In this study, we have therefore updated an existing global historical PCB emission inventory to account for exports of wastes, using global flows of e-waste as a proxy for wastes containing PCBs. Our revised emission scenarios indicate that (i) global emissions may significantly increase as result of exports of wastes in comparison to reference scenario (i.e. no exports) and (ii) different long-term temporal trends in emissions within former production and use regions versus developing regions implicated as importers of wastes are expected. In summary, our results therefore suggest that exports of wastes may lead to divergent temporal and spatial patterns of PCBs in the global environment (see Armitage et al. SETAC Vancouver). Yet, significant uncertainties in these global emission scenarios (i.e. our hypothesis with regard to the magnitude, location and timing of PCB emissions) still persist because of (i) a lack of accurate activity data (flows of relevant wastes), as well as (ii) studies allowing for accurate emission estimates from informal recycling and disposal in developing regions.

• Breivik, Knut; Armitage, James M & Wania, Frank (2014). Long-range transport of industrial-use organic contaminants with e-waste: possible implications for emissions, transport and environmental exposure.
• Breivik, Knut; Armitage, James M; Wania, Frank & Jones, Kevin C (2014). Long-range transport of e-waste: Part 1. An inventory of the global generation and trans-boundary exports towards non-OECD countries. Show summary

  Industrialized countries in the northern hemisphere have generally been considered the major source regions of various industrial organic contaminants (IOCs), such as the polychlorinated biphenyls and selected halogenated flame retardants, because that is where they had been manufactured and more extensively used. Bans on the production and use of some IOCs led to significant reductions in environmental and human contaminant burdens in those countries. Elevated burdens of IOCs are sometimes reported far from these global source regions. While the long-range transport (LRT) of IOCs by air and water to remote areas, such as the Arctic, is well characterized, far less is known about the LRT of IOCs through the trans-boundary exports of e-waste to sub-tropical and tropical regions. Contemporary burdens of IOCs that remain surprisingly high in some regions of Africa and Asia implicate these areas as recipients of obsolete products and wastes containing IOCs from developed countries. A more accurate and complete knowledge about the sources of IOCs which considers LRT of relevant wastes is essential to (i) develop rational control strategies on a global scale, and (ii) better understand and predict the global source-receptor relationships of these contaminants. The main objective of this study is to compile and evaluate existing data on the generation and trans-boundary movement of e-waste in order to develop and present (i) a first quantitative global budget of its contemporary generation, and (ii) to develop scenarios for the global movement on a global scale with emphasis on exports to non-OECD countries within sub-tropical and tropical regions. Patterns, limitations and uncertainties in the resulting budget and scenarios will be highlighted and discussed. This study represents the first step in an overall attempt to evaluate the potential implications of trans-boundary exports of e-waste for global emissions, distribution and fate of IOCs (see Armitage et al. SETAC 2014).

• Breivik, Knut; Jones, Kevin C; Sweetman, Andrew J; Armitage, James M; Wania, Frank; Zhang, Gan; Chakroborty, Paromita; Randall, Scott Gary; Eckhardt, Sabine & Schlabach, Martin (2014). Transboundary movement of wastes containing industrial POPs (iPOPs): Implications for fate, transport and research needs.
• Criado, M.A. & Breivik, Knut (2014, 20. august). Basura electronica: dónde acaban los móviles y ordenadores que tiramos?.  Spain.
• Ekeberg, Dag; Halse, Anne Karine; Schlabach, Martin; Breivik, Knut & Kallenborn, Roland (2014). Long-Range atmospheric transport and deposition of organic pollutants (POPs) in North Western Europe. Philosophiae Doctor (PhD) Thesis. 1.
• Krogseth, Ingjerd Sunde & Breivik, Knut (2014). Multimedia models and observations in concert. A powerful tool to understand and manage organic contaminants. NILU OR (NILU Oppdragsrapport). 22/2014.
• Nøst, Therese Haugdahl; Breivik, Knut; Wania, Frank; Rylander, Charlotta; Odland, Jon Øyvind & Sandanger, Torkjel M (2014). Person-specific predictions of PCBs in Norwegian Women: Valuable supplements to measurements for understanding lifetime exposures.
• Arnot, Jon A; Brown, Trevor N.; Wania, Frank; Breivik, Knut & McLachlan, Michael S. (2013). Holistic methods for chemical screening and priority setting.
• Breivik, Knut (2013). En giftfri framtid - på bekostning av fattige land?.
• Halse, Anne Karine; Eckhardt, Sabine; Schlabach, Martin; Stohl, Andreas & Breivik, Knut (2013). Evaluating a Forecast System for Long-range Atmospheric Transport Episodes of POPs. Show summary

  Background air measurements of persistent organic pollutants (POPs) within existing monitoring programs are typically conducted by use of active air samplers (AAS), but the high cost of AAS limits their spatial and temporal coverage. Sampling at many such sites furthermore occurs at fixed intervals (e.g. one day per week) without any a priori consideration of air mass transport (i.e., whether the air is likely to be polluted or not). While the current strategy is appropriate for the purpose of assessing long-term trends (years, decades), the fixed interval non-continuous sampling approach is at risk of missing out key long-range atmospheric transport (LRAT) episodes. The objectives of this study have been to (i) develop a forecast system using the Lagrangian transport model FLEXPART to predict long-range atmospheric transport episodes of POPs using PCB-28 as a model compound, (ii) to evaluate the capability of the forecast system to capture specific LRAT events at a background site in southern Norway (Birkenes) through targeted sampling (i.e. when LRAT events are predicted), (iii) to assess whether predicted LRAT events for PCB-28 coincide with elevated concentrations of additional PCBs and other POPs, and (iv) to identify source regions of POPs during individual episodes. The system has been initially evaluated by comparing targeted samples collected over 12 to 25 hours during individual LRAT episodes, with monitoring samples regularly collected over one day per week throughout 2011. The FLEXPART model was clearly successful in identifying LRAT episodes for both PCB-28 and other PCBs. The model fails to accurately reproduce the magnitude of PCB-28 concentrations during individual episodes, but this can be mainly attributed to uncertainties in the absolute emission rates of PCB-28 used to drive simulations. We conclude that forecasting of pollution episodes has the potential to add value to relevant monitoring efforts which are normally collecting active air samples at fixed intervals in a non-continuous manner. Observations targeted at strong pollution episodes (as in this study) or on transport from specific source regions with highly uncertain emissions (as could be done in a very similar forecasting framework) could significantly enhance our understanding of POP sources.

• Kierkegaard, Amelie; McLachlan, Michael S.; Breivik, Knut; Arnot, Jon A & Wania, Frank (2013). Prioritization, screening and identification of organosilicon contaminants in the environment. Show summary

  A mass balance model of chemical fate and bioaccumulation in the environment was used to rank 287 high- and low-production volume organosilicon compounds for their concentration in the environment and in top predators. Key physical chemical properties of each chemical were estimated using quantitative structure-activity relationships (QSARs) and a total emission estimate of each chemical was made using information, which included amounts entering commerce and emission factors. Based on the model predicted concentrations in air, sediment and human tissue, chemicals were selected for screening through environmental sampling and analysis. Known environmental organosilicon contaminants such as the cyclic and linear volatile methyl siloxanes (VMS) were excluded as well as structures subject to rapid hydrolysis, a feature which was not taken into account in the model simulations because of current limitations in predicting hydrolysis half-lives with QSARs. Analytical standards were only commercially available for half of the remaining 30 organosilicon compounds. Ten of these were not stable in solution, which left 5 organosilicon compounds eligible for environmental screening. These were tetrakis(trimethylsilyloxy)silane, phenyl-tris(trimethylsiloxy)silane, trifluoropropyltrimethylcyclotrisiloxane, trifluoropropylmethylcyclotetrasiloxane and tetraphenyltrisiloxane. Four of these chemicals were identified in sewage sludge, in sediment from Stockholm harbor, and in Stockholm ambient air samples. The trifluoropropyl-substituted siloxanes were analysed with UPLC-MS/MS, the others with GC-MS. Trifluoropropyltrimethylcyclotrisiloxane was solely detected as its corresponding linear diol. To date it is unclear whether the diol is present in the environment as such or formed during extraction or cleanup. The concentrations of the chemicals ranged from pg m-3 in air up to ng g-1 d.w. in sewage sludge, which are orders of magnitude below the levels of cyclic VMS (such as D5) in the same matrices.

• Krogseth, Ingjerd Sunde; Breivik, Knut; Schlabach, Martin; Arnot, Jon A & Wania, Frank (2013). Evaluating the environmental fate of short-chain chlorinated paraffins (SCCPs) in the Nordic environment using a dynamic multimedia model.
• Krogseth, Ingjerd Sunde; Breivik, Knut; Schlabach, Martin; McLachlan, Michael S; Wania, Frank & Arnot, Jon A (2013). Integrated modeling and monitoring of emerging organic contaminants in the Nordic region.
• Krogseth, Ingjerd Sunde; Breivik, Knut; Schlabach, Martin; McLachlan, Michael S; Wania, Frank & Arnot, Jon A (2013). Integrated modeling and monitoring of emerging organic contaminants in the Nordic region.
• Krogseth, Ingjerd Sunde; Kallenborn, Roland; Breivik, Knut & Schlabach, Martin (2013). From emissions to exposure - Environmental behaviour of volatile methyl siloxanes and short-chain chlorinated paraffins.
• Krogseth, Ingjerd Sunde; Zhang, Xianming; Lei, Ying Duan; Wania, Frank & Breivik, Knut (2013). Calibration of a passive air sampler for volatile methyl siloxanes.
• Krogseth, Ingjerd Sunde; Zhang, Xianming; Lei, Ying Duan; Wania, Frank & Breivik, Knut (2013). Calibration of a passive air sampler for volatile methyl siloxanes. Show summary

  The atmosphere is a key compartment for understanding the environmental fate and behavior of volatile methyl siloxanes (VMS). Due to their fairly high volatility, VMS are mainly emitted to, and largely remain in, the atmosphere where they are relatively persistent and subject to long-range transport. However, also because of their high volatility, the applicability of standard air sampling methods to VMS cannot be assumed and must be proven. The purpose of this study was to evaluate the suitability and to calibrate an existing, polystyrene-divinylbenzene co-polymeric resin based passive air sampler (XAD-PAS) for VMS. The XAD-PAS has been tested and applied for different compounds and environmental conditions, but has not yet been calibrated for more volatile compounds like VMS. To achieve this, a number of samplers were deployed at a suburban site in Toronto, Canada, and collected after different time points. Simultaneously the VMS concentration in air at the sampling site was measured using an active air sampling method based on solid phase extraction cartridges, previously validated and applied for VMS. The uptake in the XAD-PAS of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and three linear VMS was linear throughout the whole deployment period of 98 days. The sampling rate was approximately 0.5 m3/day for all congeners. For hexamethylcyclotrisiloxane (D3) and dodecamethylcyclohexasiloxane (D6) the blank levels were too high relative to the concentrations of D3 and D6 in air at the site to assess the uptake in the sampler. Subsequent to the calibration study, XAD-PAS samplers were deployed at 26 sites in Toronto and the surrounding area to evaluate the influence of both population density and proximity to sewage treatment plants (STPs) on urban atmospheric levels of VMS. The sites could mainly be binned into three groups; two STP sites with strongly elevated levels of VMS in air, the urban sites with intermediate levels; and three rural background sites with very low levels of VMS.

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