Development of a supramolecular solvent-based extraction method for application to quantitative analyses of a wide range of organic contaminants in indoor dust.

This study investigates the efficacy of supramolecular solvent (SUPRAS) in extracting a diverse spectrum of organic contaminants from indoor dust. Initially, seven distinct SUPRAS were assessed across nine categories of contaminants to identify the most effective one. A SUPRAS comprising Milli-Q water, tetrahydrofuran, and hexanol in a 70:20:10 ratio, respectively, demonstrated the best extraction performance and was employed for testing a wider array of organic contaminants. Furthermore, we applied the selected SUPRAS for the extraction of organic compounds from the NIST Standard Reference Material (SRM) 2585. In parallel, we performed the extraction of NIST SRM 2585 with conventional extraction methods using hexane:acetone (1:1) for non-polar contaminants and methanol (100%) extraction for polar contaminants. Analysis from two independent laboratories (in Norway and the Czech Republic) demonstrated the viability of SUPRAS for the simultaneous extraction of twelve groups of organic contaminants with a broad range of physico-chemical properties including plastic additives, pesticides, and combustion by-products. However, caution is advised when employing SUPRAS for highly polar contaminants like current-use pesticides or volatile substances like naphthalene.

Pelagic vs Coastal-Key Drivers of Pollutant Levels in Barents Sea Polar Bears with Contrasted Space-Use Strategies.

In the Barents Sea, pelagic and coastal polar bears are facing various ecological challenges that may explain the difference in their pollutant levels. We measured polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenyl ethers in fat, and perfluoroalkyl substances in plasma in pelagic and coastal adult female polar bears with similar body condition. We studied polar bear feeding habits with bulk stable isotope ratios of carbon and nitrogen. Nitrogen isotopes of amino acids were used to investigate their trophic position. We studied energy expenditure by estimating field metabolic rate using telemetry data. Annual home range size was determined, and spatial gradients in pollutants were explored using latitude and longitude centroid positions of polar bears. Pollutant levels were measured in harp seals from the Greenland Sea and White Sea-Barents Sea as a proxy for a West-East gradient of pollutants in polar bear prey. We showed that pelagic bears had higher pollutant loads than coastal bears because (1) they feed on a higher proportion of marine and higher trophic level prey, (2) they have higher energy requirements and higher prey consumption, (3) they forage in the marginal ice zones, and (4) they feed on prey located closer to pollutant emission sources/transport pathways.

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.

BACKGROUND: Human biomonitoring studies have demonstrated decreasing concentrations of many persistent organic pollutants (POPs) in years after emission peaks. OBJECTIVES: To describe time trends of POPs in blood using four cross-sectional samples of 30 year olds from Tromsø, Norway across 1986-2007, and to compare the measured concentrations of polychlorinated biphenyl 153 (PCB-153) to model-estimated values. A second objective was to compare the repeated cross-sectional time trends with those observed in our previous longitudinal study using repeated individual measurements in older men from the same surveys. METHODS: Serum from 45 persons aged 30 years in each of the following years: 1986, 1994, 2001, and 2007 was analyzed for 14 POPs. Further, predicted concentrations of PCB-153 in each sampling year were derived using the emission-based CoZMoMAN model. RESULTS: The median decreases in summed serum POP concentrations (lipid-adjusted) in 1994, 2001, and 2007 relative to 1986 were - 71%, - 81%, and - 86% for women and - 65%, - 77%, and - 87% for men, respectively. The overall time trend in predicted PCB-153 concentrations demonstrated agreement with the observed trend although model predictions were higher than the measured concentrations at all time points. Compared to our previous longitudinal study of repeated individual measurements in older men, similar although more prominent declines were observed in the younger cross-sectional samples. DISCUSSION: Observed declines in serum concentrations from 1986 to 2007 were substantial for legacy POPs in men and women at reproductive ages in Northern Norway and are generally consistent with previous longitudinal biomonitoring efforts in the study population. The measured concentrations and observed declines likely reflect a combination of recent and historic exposures. Small differences in time trends observed between the studies could be attributed to different study designs (i.e. the chosen age group or sex and cross-sectional versus repeated individual measurement sampling).

Perfluoroalkyl substances (PFASs) in air-conditioner filter dust of indoor microenvironments in Greece: Implications for exposure.

The occurrence of perfluoroalkyl substances (PFASs) was for the first time investigated in various working microenvironments (internet cafes, electronics shops, coffee shops, restaurants, etc.) in Thessaloniki, Greece, using the dust trapped by central air conditioner (A/C) filters. Perfluorooctane sulfonic acid (PFOS) was found in the range from 16 to 227 ng g-1, however it was detectable in only 30% of samples. On the contrary, perfluorohexanoic acid (PFHxA) was found in 85% of samples in the range from 3.6 to 72.5 ng g-1, while 90-95% of samples exhibited perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDcA) and perfluorododecanoic acid (PFDoDA) in the range from 10-653 ng g-1, 3.2-7.4 ng g-1 and 3.8-13.1 ng g-1, respectively. The PFAS profile varied largely among the different microenvironment categories suggesting different sources. Estimated daily intakes through dust ingestion were calculated.

Emission Changes Dwarf the Influence of Feeding Habits on Temporal Trends of Per- and Polyfluoroalkyl Substances in Two Arctic Top Predators.

We monitored concentrations of per- and polyfluoroalkyl substances (PFASs) in relation to climate-associated changes in feeding habits and food availability in polar bears (Ursus maritimus) and arctic foxes (Vulpes lagopus) (192 plasma and 113 liver samples, respectively) sampled from Svalbard, Norway, during 1997-2014. PFASs concentrations became greater with increasing dietary trophic level, as bears and foxes consumed more marine as opposed to terrestrial food, and as the availability of sea ice habitat increased. Long-chained perfluoroalkyl carboxylates (PFCAs) in arctic foxes decreased with availability of reindeer carcasses. The ∼9-14% yearly decline of C6-8 perfluoroalkyl sulfonates (PFSAs) following the cease in C6-8 PFSA precursor production in 2001 indicates that the peak exposure was mainly a result of atmospheric transport of the volatile precursors. However, the stable PFSA concentrations since 2009-2010 suggest that Svalbard biota is still exposed to ocean-transported PFSAs. Long-chain ocean-transported PFCAs increased 2-4% per year and the increase in C12-14 PFCAs in polar bears tended to level off since ∼2009. Emerging short-chain PFASs showed no temporal changes. Climate-related changes in feeding habits and food availability moderately affected PFAS trends. Our results indicate that PFAS concentrations in polar bears and arctic foxes are mainly affected by emissions.

Targeted PFAS analyses and extractable organofluorine - Enhancing our understanding of the presence of unknown PFAS in Norwegian wildlife.

With the current possible presence of thousands of PFAS compounds in industrial emissions, there is an increasing need to assess the impacts of PFAS regulation of conventional PFAS on one hand and the exposure to emerging and yet unknown PFAS on the other. Today's analytical methodologies using targeted approaches are not sufficient to determine the complete suite of PFAS present. To evaluate the presence of unknown PFAS, we investigated in this study the occurrence of an extended range of target PFAS in various species from the marine and terrestrial Norwegian environment, in relation to the extractable organofluorine (EOF), which yields the total amount of organofluorine. The results showed a varying presence of extractable fluorinated organics, with glaucous gull eggs, otter liver and polar bear plasma showing the highest EOF and a high abundance of PFAS as well. The targeted PFAS measurements explained 1% of the organofluorine for moose liver as the lowest and 94% for otter liver as the highest. PFCAs like trifluoroacetic acid (TFA, reported semi-quantitatively), played a major role in explaining the organic fluorine present. Emerging PFAS as the perfluoroethylcyclohexane sulfonate (PFECHS), was found in polar bear plasma in quantifiable amounts for the first time, confirming earlier detection in arctic species far removed from emission sources. To enable a complete organic fluorine mass balance in wildlife, new approaches are needed, to uncover the presence of new emerging PFAS as cyclic- or ether PFAS together with chlorinated PFAS as well as fluorinated organic pesticides and pharmaceuticals.

Time trends of perfluoroalkyl substances in blood in 30-year old Norwegian men and women in the period 1986-2007.

Biomonitoring studies are helpful tools and can increase our knowledge on time trends in human blood concentrations of PFASs: how they relate to emission trends and the potential prenatal exposure for future generations. In this study, serum was sampled in cross-sections of men and women who were 30 years old in each of the years 1986, 1994, 2001, and 2007 in Northern Norway and analyzed for 23 PFASs. Differences in serum concentrations across sampling years were investigated graphically and with significance testing and compared with those observed in our previous longitudinal study using repeated individual measurements in older men in the same years. The results demonstrate overall increasing blood burdens of PFASs in men and women in reproductively active ages during 1986-2001 and decreases until 2007. However, longer chained PFASs were still increasing in 2007 indicating divergent time trends between the different PFASs, underlining the importance of continued biomonitoring. Comparisons between 30-year-old men and older men within the same population demonstrated variation in time trends in the exact same years, underlining that biomonitoring studies must regard historic exposures and birth cohort effects.

Perfluorinated compounds in maternal serum and cord blood from selected areas of South Africa: results of a pilot study.

There is limited information about both environmental and human perfluorinated compounds (PFCs) concentrations in the southern hemisphere, and for the first time, concentrations of these compounds are reported in maternal serum and cord blood of South African women. The majority of the participants were of African Black ethnicity, with a similar socioeconomic status. In maternal serum perfluorooctane sulfonate (PFOS) was found to be the most abundant PFC (1.6 ng mL(-1)), followed by perfluorooctanoate (PFOA: 1.3 ng mL(-1)) and perfluorohexane sulfonate (PFHxS: 0.5 ng mL(-1)); however, in cord blood PFOA was the most abundant compound (1.3 ng mL(-1)) followed by PFOS (0.7 ng mL(-1)) and PFHxS (0.3 ng mL(-1)). Linear PFOS constituted 58% of the sum of PFOS, comparable with a reported percentage from Australia. Differences in PFC concentrations between communities were found, with the highest concentrations in urban and semi-urban areas. The median maternal PFOS concentration was lower than has been reported in other studies, whereas the PFOA concentration was the same. This clearly indicates that the exposure pathway is different from the western world. Significant differences in housing quality were observed and the urban and sub-urban community had the highest living and housing standards. Possible exposure pathways could be different from those elucidated in the western world with the exception of the urban community in our study that showed higher living standards in general and easier access to modern consumer products.

Contaminants in Atlantic walruses in Svalbard part 1: Relationships between exposure, diet and pathogen prevalence.

This study investigated relationships between organohalogen compound (OHC) exposure, feeding habits, and pathogen exposure in a recovering population of Atlantic walruses (Odobenus rosmarus rosmarus) from the Svalbard Archipelago, Norway. Various samples were collected from 39 free-living, apparently healthy, adult male walruses immobilised at three sampling locations during the summers of 2014 and 2015. Concentrations of lipophilic compounds (polychlorinated biphenyls, organochlorine pesticides and polybrominated diphenyl ethers) were analysed in blubber samples, and concentrations of perfluoroalkylated substances (PFASs) were determined in plasma samples. Stable isotopes of carbon and nitrogen were measured in seven tissue types and surveys for three infectious pathogens were conducted. Despite an overall decline in lipophilic compound concentrations since this population was last studied (2006), the contaminant pattern was similar, including extremely large inter-individual variation. Stable isotope ratios of carbon and nitrogen showed that the variation in OHC concentrations could not be explained by some walruses consuming higher trophic level diets, since all animals were found to feed at a similar trophic level. Antibodies against the bacteria Brucella spp. and the parasite Toxoplasma gondii were detected in 26% and 15% of the walruses, respectively. Given the absence of seal-predation, T. gondii exposure likely took place via the consumption of contaminated bivalves. The source of exposure to Brucella spp. in walruses is still unknown. Parapoxvirus DNA was detected in a single individual, representing the first documented evidence of parapoxvirus in wild walruses. Antibody prevalence was not related to contaminant exposure. Despite this, dynamic relationships between diet composition, contaminant bioaccumulation and pathogen exposure warrant continuing attention given the likelihood of climate change induced habitat and food web changes, and consequently OHC exposure, for Svalbard walruses in the coming decades.

Exposure to per- and polyfluoroalkyl substances through the consumption of fish from lakes affected by aqueous film-forming foam emissions - A combined epidemiological and exposure modeling approach. The SAMINOR 2 Clinical Study.

Releases of aqueous film-forming foams (AFFFs) from airport firefighting activities have been identified as important local point sources of per- and polyfluoroalkyl substances (PFASs) in nearby waterways. PFASs can be taken up by fish, and in turn by the humans that consume them. Despite the global extent of AFFF emissions, few studies exist on related impacts on humans. We aimed to investigate the associations between the consumption of fish from AFFF-affected waters and serum PFAS concentrations in humans using a combination of statistical tools, empirical data, and toxicokinetic modeling. Participants of the SAMINOR 2 Clinical Study were the basis for this study sample, which comprised 74 persons. Fifty-nine participants who reported consuming fish from AFFF-affected waters and 15 nonconsumers completed a questionnaire and gave serum samples. Participants were classified based on their consumption of trout and char: high (n=16), moderate (n=16), low (n=27), and nonconsumers (n=15); and serum samples were tested for the presence of 15 PFASs. Perfluorooctane sulfonic acid (PFOS) was found in all participants, with the highest concentrations detected in the high consumption group (geometric means, 28ng/mL) compared to the low consumption group and nonconsumers (10 and 11ng/mL, respectively). In an analysis of variance contrast model, a significant, positive increasing trend was seen for fish consumption and PFOS, perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). Toxicokinetic modeling allowed us to predict the median increases in serum concentrations of PFOS, PFHxS, and PFNA among high consumers within a factor of 2.2. The combination of statistical evaluation and toxicokinetic modeling clearly demonstrated a positive relationship between consumption of fish from AFFF-affected waters and serum PFAS concentrations. Further studies on dietary exposure to other PFASs present in AFFF and its consequences on human health are warranted.

Persistent and emerging pollutants in the blood of German adults: Occurrence of dechloranes, polychlorinated naphthalenes, and siloxanes.

Human biomonitoring is a valid method to determine exposure, identify time trends, and monitor the effects of restrictions and measures. To characterize the recent exposure of Germans to persistent or emerging substances, we analyzed 4 dechloranes, 33 polychlorinated naphthalenes (PCNs), and 3 cyclic volatile methyl siloxanes (cVMS) in 42 plasma samples. The samples were collected from blood donors on a random selection. The median values of both Dechlorane Plus (DDC-CO) isomers were 1.23ng/gl.w. for anti- and 0.77ng/gl.w. for syn-DDC-CO. The two other dechloranes were found at lower levels. The median level of ∑-PCNs was 575pg/gl.w. (range: 101-1406pg/gl.w.). On average, the levels of PCNs in plasma were dominated by the congeners CN73, CN66/67, and CN51, which were responsible for approximately 71% of the total amount of PCNs. The cVMS octa-, deca-, and dodecamethylcyclotetrasiloxane could be determined in only some samples, with maximum values of 0.73, 0.48, and 0.79µg/l, respectively. Regarding dechloranes, our results are similar to those from other western countries but slightly lower than results from China. The levels of PCNs in German blood are similar to those observed in the U.S.A., but considerably lower than those reported for Korea. Using a preliminary TEF (toxic equivalency factor), the mean TEQ of the 9 quantifiable PCNs in Germany was low (0.36pg TEQ/gl.w.). The PCN levels in our study group are lower compared to previous studies.

A broad cocktail of environmental pollutants found in eggs of three seabird species from remote colonies in Norway.

Eggs of 3 seabird species, common eider (Somateria mollisima), European shag (Phalacrocorax aristotelis aristotelis), and European herring gull (Larus argentatus), were surveyed for a broad range of legacy and emerging pollutants to assess chemical mixture exposure profiles of seabirds from the Norwegian marine environment. In total, 201 chemical substances were targeted for analysis ranging from metals, organotin compounds, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and associated metabolites, chlorinated paraffins, chlorinated and nonchlorinated organic pesticides, per- and polyfluoroalkyl substances (PFAS), dechlorane plus, octachlorostyrene, brominated flame retardants (BFRs), organophosphorous compounds, brominated and alkyl phenols, cyclic siloxanes, and phthalates. Of the chemicals targeted, 149 substances were found above the detection limits, with metals dominating the contaminant profile and comprising 60% of the total contaminant load. Polychlorinated biphenyls, pesticides, organophosphorous compounds, and PFAS were the dominant contaminant classes of organic pollutants found within the seabird species, with the highest loads occurring in herring gulls, followed by shag, and common eider. New generation pollutants (e.g., PFAS, organophosphorous compounds, and alkylphenols) were detected at similar or higher concentrations than the legacy persistent organic pollutants (POPs). Time trends of reported concentrations of legacy POPs appear to have decreased in recent decades from the Norwegian coastal environment. Concentrations of detected pollutants do not appear to have a negative effect on seabird population development within the sampling area. Additional stress caused by pollutants, however, may affect seabird health more at the individual level.

Contaminant levels in the world's northernmost harbor seals (Phoca vitulina).

The world's northernmost harbor seal (Phoca vitulina) population, which inhabits Svalbard, Norway, constitutes a genetically distinct population. The present study reports concentrations of 14 PCBs, 5 chlordanes, p,p'-DDT, p,p'-DDE, hexachlorobenzene (HCB), mirex, and, α-, ß-and γ-hexachlorocyclohexane (HCH) in blubber, and pentachlorophenol, 4-OH-heptachlorostyrene, 10 OH-PCBs and 14 perfluoroalkyl substances in plasma of live-captured harbor seals from this population (4 males, 4 females, 4 juveniles), sampled in 2009-2010. Concentrations of PCB 153, p,p'-DDE, oxychlordane, α-HCH and mirex and perfluoroalkyl sulfonates in Svalbard harbor seals were considerably lower than harbor seal from more southerly populations, while concentrations of HCB, OH-PCBs and perfluoroalkyl carboxylates were similar for harbor seals from Svalbard and southern areas. Concentrations of PCBs and pesticides in the Svalbard harbor seals were 60-90% lower than levels determined a decade ago in this same population. Current concentrations of legacy POPs are not considered a health risk to the harbor seals from Svalbard.

Partition of perfluoroalkyl substances (PFASs) in whole blood and plasma, assessed in maternal and umbilical cord samples from inhabitants of arctic Russia and Uzbekistan.

Perfluoroalkyl substances (PFASs) are ubiquitous in the environment world-wide. Our overall objective was to assess the exposure to PFASs experienced by delivering women and their new-borns in the industrial city of Norilsk (arctic Russia) and the rural Aral Sea region of Uzbekistan, with the secondary objective of evaluating the distribution of PFASs between blood cell and plasma fractions. Six PFASs were detected in every sample from Norilsk city with the plasma concentration sequence of: PFOS≫PFOA>PFNA>FOSA>PFHxS>PFUnDA. In the Uzbekistani samples, only PFOS was reported above the MDL (0.08 ng/mL). The median plasma concentrations of PFOS of 11.0 ng/mL for the Norilsk mothers was comparable to that reported for western countries, while that for Uzbekistan was considerably lower (0.23 ng/mL). Apparent increases in the maternal-cord concentration ratios for both whole blood and plasma were evident with the length of the carbon chain for both the carboxylate and the sulfonate PFASs. The median value of this ratio for FOSA in plasma was the lowest, while that for whole blood was the highest. Other than for FOSA, the observed plasma-whole blood concentration ratios for maternal and umbilical cord blood were consistent with a priori calculations using appropriate packed cell and plasma volumes for neonates and pregnant women at term. Clearly FOSA favored whole blood, and acid-base equilibrium calculations suggested that the resonance-stabilized sulfonamidate ion resides in the blood cell fraction. Thus for PFASs and related compounds with pK values with magnitudes comparable to physiological pH, it is pertinent to measure the cell-associated fraction (separately or as whole blood). Our study illustrates that consideration of both the physico-chemical properties of the contaminants and the physiological attributes of blood matrices were helpful in the interpretation of our findings.

Plasma concentrations of cyclic volatile methylsiloxanes (cVMS) in pregnant and postmenopausal Norwegian women and self-reported use of personal care products (PCPs).

Dermal application of personal care products (PCPs) is considered an important human exposure route for siloxanes. Their presence as minor or major constituents in many personal care products (PCPs) and cosmetics is of concern for human exposure. The aim of this study was to quantify cyclic volatile methylsiloxanes (cVMS) in blood plasma of pregnant and postmenopausal women, and to investigate possible links to self-reported use of PCPs for the latter group. Participants were recruited from two studies, namely the Norwegian Women and Cancer Study (NOWAC) and the North Norwegian Mother-and-child Study (MISA). For the NOWAC cohort, 94 plasma samples from postmenopausal women were analyzed (blood drawn in 2005) and information about PCP use and breast implants was derived from a self-administered questionnaire. In the MISA study, the collection of the plasma samples (blood drawn in 2009) constituted a re-sampling because the original serum vacutainers used were contaminated with cVMS. D4 (octamethylcyclotetrasiloxane) was the dominant compound in plasma for both cohorts. For the NOWAC samples, more than 85% of the women had D4 concentrations above the LOQ (2.74 ng/mL), while the detection frequency was only 18% for the MISA participants. The highest cVMS plasma concentrations were observed for D4: 12.7 ng/mL (NOWAC) and 2.69 ng/mL (MISA). For the other cVMS, decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) concentrations were below the detection limit in most samples. There was no significant correlation between the concentrations of D4 and the reported total body cream use. Sampling time (2005 versus 2009) and age of the donors could explain the differences between the two cohorts.