Comparison of aggregated exposure to perfluorooctanoic acid (PFOA) from diet and personal care products with concentrations in blood using a PBPK model - Results from the Norwegian biomonitoring study in EuroMix.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) constitute a large group of compounds that are water, stain, and oil repellent. Numerous sources contribute to the blood levels of PFAS in the European population. The main contributor for perfluorooctanoic acid (PFOA) is food, house dust, consumer products and personal care products (PCPs). OBJECTIVES: The purpose of the present work is to calculate the dietary and dermal external exposure to PFOA, estimate the aggregated internal exposure from diet and PCPs using a PBPK model, and compare estimates with measured concentrations. METHODS: Detailed information on diet and PCP use from the EuroMix study is combined with concentration data of PFOA in food and PCPs in a probabilistic exposure assessment. A physiologically based pharmacokinetic model (PBPK) was further refined by incorporating a dermal exposure pathway, and changes in the kidney and faecal excretion. RESULTS: The aggregated internal exposure using the PBPK model shows that the major contributor to the internal exposure is diet for both males and females. The estimated internal exposure of PFOA for the EuroMix population was in the same range but lower than the measured blood concentrations using the lower bound (LB) external exposure estimates, showing that the LB estimates are underestimations. For seven females the internal exposure of PFOA were higher from PCPs than from diet. CONCLUSION: PCPs and diet contributed in the same range to the internal PFOA exposure for several women participating in EuroMix. This calls for additional studies on exposure to PFOA and possibly other PFAS from PCPs, especially for women. Overall, PBPK modelling was shown as valuable tool in understanding the sources of PFOA exposure and in guiding risk assessments and regulatory decisions.

Persistent organic pollutants and organophosphate esters in feathers and blood plasma of adult kittiwakes (Rissa tridactyla) from Svalbard - associations with body condition and thyroid hormones.

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs) and organophosphate esters (OPEs) were assessed in blood plasma and feathers of 19 adult black-legged kittiwakes (Rissa tridactyla) breeding in two colonies (Blomstrandhalvøya and Krykkjefjellet) at the Arctic archipelago, Svalbard. Potential associations with body condition index (BCI) and thyroid hormones were investigated. All compound classes were detected in both blood plasma and feathers, but due to low sample size and volumes, OPEs could only be quantified in four individuals, warranting larger follow-up studies. Kittiwakes breeding at Blomstrandhalvøya had significantly higher concentrations of organic pollutants in blood plasma than kittiwakes breeding at Krykkjefjellet (p < 0.001). Concentrations in blood plasma and feathers did not significantly correlate for any of the investigated compounds, and feather concentrations did not differ significantly between the colonies. This suggests that pollutant levels in adult kittiwake feathers do not reflect local contamination at breeding sites and are as such not useful to monitor local contamination at Svalbard. Significant negative associations between BCI and most pollutants were found in both populations, whereas significant correlations between the BCI, the ratio of total triiodothyronine to free triiodothyronine (TT3:fT3), and several pollutants were only found for kittiwakes from Blomstrandhalvøya (all r ≥ -0.60 and p ≤ 0.05). This indicates that higher levels of circulating pollutants during the breeding period covary with the TT3: fT3 ratio, and may act as an additional stressor during this period.

Per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern Norway.

Plasma samples from nestlings of two top predators, White-tailed eagle (Haliaeetus albicilla) and Northern goshawk (Accipiter gentilis) from northern Norway were analysed for a wide range of per- and polyfluoroalkyl substances (PFASs). Body feathers from the White-tailed eagles were also analysed and significant associations between specific PFASs in blood plasma and body feathers were found (0.36

Tracking pan-continental trends in environmental contamination using sentinel raptors-what types of samples should we use?

Biomonitoring using birds of prey as sentinel species has been mooted as a way to evaluate the success of European Union directives that are designed to protect people and the environment across Europe from industrial contaminants and pesticides. No such pan-European evaluation currently exists. Coordination of such large scale monitoring would require harmonisation across multiple countries of the types of samples collected and analysed-matrices vary in the ease with which they can be collected and the information they provide. We report the first ever pan-European assessment of which raptor samples are collected across Europe and review their suitability for biomonitoring. Currently, some 182 monitoring programmes across 33 European countries collect a variety of raptor samples, and we discuss the relative merits of each for monitoring current priority and emerging compounds. Of the matrices collected, blood and liver are used most extensively for quantifying trends in recent and longer-term contaminant exposure, respectively. These matrices are potentially the most effective for pan-European biomonitoring but are not so widely and frequently collected as others. We found that failed eggs and feathers are the most widely collected samples. Because of this ubiquity, they may provide the best opportunities for widescale biomonitoring, although neither is suitable for all compounds. We advocate piloting pan-European monitoring of selected priority compounds using these matrices and developing read-across approaches to accommodate any effects that trophic pathway and species differences in accumulation may have on our ability to track environmental trends in contaminants.

Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species.

The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑7PCB concentrations (range: 61-115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.

The search for alternative aqueous film forming foams (AFFF) with a low environmental impact: physiological and transcriptomic effects of two Forafac(®) fluorosurfactants in turbot.

Fluorosurfactants are the key components in aqueous film forming foams (AFFF). They provide these fire fighting agents with the required low surface tension and they enable film formation on top of lighter fuels to prevent burn back. Development of effective and environmentally acceptable PFOS alternatives is one of the most important priorities in the fire fighting foam industry. DuPont™ offers the fluorosurfactant mixtures Forafac(®)1157 and Forafac(®)1157N for the formulation of AFFFs which are alternatives to the persistent and toxic perfluorooctane sulphonate (PFOS). Ecotoxicological testing of these inadequately documented mixtures is necessary to include them in AFFF hazard and risk assessment. Juvenile turbot (Scophthalmus maximus) were exposed for 14 days to 0.1; 0.5 and 1.5mg/L of the fluorosurfactant mixtures used in Forafac(®)1157 and Forafac(®)1157N. In an initial transcriptomics experiment, microarray analysis revealed differentially expressed transcripts of genes which were mainly involved in digestion and in the immune system. This discovery-driven screening approach offered the basis for new hypotheses that were tested in two subsequent experiments in which food intake, energy reserves, growth and a set of haematological parameters were examined. Additionally, effects of the two mixtures were compared to those of PFOS. Based on the results of this study, the mode of action of Forafac(®)1157N was the activation of the acute phase reaction resulting in increased leukocyte concentrations and the inhibition of growth due to the high energetic cost of toxicant exposure. For Forafac(®)1157, evidences of immunosuppression were found on the transcriptional level and the altered differential leukocyte profiles indicated that stress was induced in these fish. However, food intake, energy reserves and growth were not compromised, even at high exposure concentrations, which was in contrast to the effects seen after PFOS exposure. Taking into account that Forafac(®)1157 appeared to be less toxic than PFOS, this mixture could be considered as a more environmentally acceptable PFOS alternative for the use in AFFFs.

Perfluorinated and other persistent halogenated organic compounds in European shag (Phalacrocorax aristotelis) and common eider (Somateria mollissima) from Norway: a suburban to remote pollutant gradient.

Samples of two marine bird species, European shag (Phalacrocorax aristotelis) and common eider (Somateria mollissima) sampled at a remote coastal site in Norway were analysed for POPs and PFCs. Additionally samples of common eider were analysed from two other locations in Norway, representing a gradient from "densely populated" to "remote". The variety, concentration and distribution of lipophilic POPs in comparison to PFCs were investigated. PCBs were the dominating group of contaminants in the analysed egg samples. Shag eggs had median sum PCBs levels of 4,580 ng/g l.w. in 2004. Six different PBDE congeners could be detected in the shag eggs. BDE 47 and 100 were the main contributors with 24 and 27 ng/g l.w. respectively, sum PBDEs was 90 ng/g l.w. Relatively high concentrations of chlordanes were found with a total sum of 903 ng/g l.w. Of other OCs, toxaphene 26 and 52 together (sum 657 ng/g l.w.) and HCB (165 ng/g l.w.) were contributing majorly to the egg burden. Sum HCHs were low; only 54 ng/g l.w. PFOS was the main PFC in egg, plasma and liver samples. Similar median levels of 29, 32 and 27 ng/g w.w. were observed. PFOSA, PFH x S, and PFDcA were observed additionally in all shag samples at minor concentrations with the exception of elevated levels observed in liver for PFOSA and PFDcA with median levels of 7.6 and 7.9 ng/g w.w., respectively. In common eider eggs, the POP concentrations decreased up to 1/8th along the sampled spatial gradient from suburban to remote. Of the 9 detected PFCs, PFOS dominated all samples by one order of magnitude, followed by PFOA. Sum PFC concentrations were twice as high at the two fjord sites compared to the remote site. Shorter chained PFCAs like PFOA and PFNA could be detected in the eider eggs whilst being absent in shag eggs.

Historical trends in persistent organic pollutants and metals recorded in sediment from Lake Ellasjøen, Bjørnøya, Norwegian Arctic.

Ellasjøen receives contaminants from both atmospheric and biological transport (seabird guano). Historical trends of selected persistent organic pollutants and metals were determined by interpretation of down-core contaminant profiles in conjunction with sediment layer ages, determined by the (210)Pb method. Polychlorinated biphenyls (PCBs) and dichloro-diphenyl-trichloroethane and metabolites (DDTs) increased from about 1930 until 1970 (max. sum PCBs 71.8 ng/g dry weight (dw), max sum DDTs 4.0 ng/g dw), declining afterwards to 46.4 ng/g dw and 1.6 ng/g dw, respectively. Polybrominated diphenylethers (PBDEs) concentrations are increasing in Ellasjøen, reaching 0.73 ng/g dw in 2001. Hexabromocyclododekane (HBCD) was measured only in sediment from 1-2 cm depth (0.43 and 3.88 ng/g dw of alpha- and gamma-HBCD, respectively). Most metals (As, Cd, Co, Ni and Zn) showed a similar pattern as PCBs. No clear trends were observed for Cr, Pb or V. Mercury (Hg) has increased gradually since the beginning of the industrial era.

Brominated flame retardants and other organobromines in Norwegian predatory bird eggs.

A set of 62 unhatched eggs was collected from six different predatory bird species throughout Norway after incubation period was completed. They were analysed for PBDE, PBB, TBBP A and naturally occurring halogenated compounds. BDE 47, 99 and 153 were the dominating congeners, with species dependent PBDE patterns. BDE 153 was observed as the most abundant congener in eggs of peregrine falcon, golden eagle and merlin. The highest PBDE level (sum of nine congeners) was found in eggs of white-tailed sea eagle with up to 800ng/gww (median sumPBDE: 184ng/gww), followed by eggs of peregrine falcon and osprey (median sumPBDE: 155 and 105ng/gww, respectively). Golden eagle eggs showed the lowest concentration of all species (median sumPBDE: 3ng/gww). The levels in the peregrine falcon are similar to those found earlier in the Baltic region [Lindberg, P., Sellstrom, U., Haggberg, L., de Wit, C.A., 2004. Higher brominated diphenyl ethers and hexabromocyclododecane found in eggs of peregrine falcons (Falco peregrinus) breeding in Sweden. Environmental Science & Technology. 38 (1), 93-96]. The differences between species are not fully explainable, due to lack of data from the major food species. BB 101 and 153 were found in eggs of all investigated bird species. Especially in samples of white-tailed sea eagle, peregrine falcon and goshawk additional unknown penta- and hexabrominated biphenyls were detected. TBBP A was detected in all of eight eggs analysed sampled from four different bird of prey species. The naturally occurring halogenated compounds Q1, the dibromotrichloro monoterpene MHC-1, and 2,4,6-tribromoanisole (TBA) were detected in all of seven analysed samples except for one peregrine falcon egg.

Organochlorines in egg samples from Norwegian birds of prey: congener-, isomer- and enantiomer specific considerations.

The content of chlorinated persistent organic pollutants was determined in a total of 44 egg samples from 8 different raptor species collected throughout Norway in the period 1991-1997. The content of 8 chlorinated bornanes, 9 chlorinated pesticides, and 15 polychlorinated biphenyl congeners (PCB) were determined. The highest average concentrations for PCB were found for eggs from White-tailed Sea Eagle and Peregrine Falcon (average sum PCB concentration: 8.9 and 9.1 microg/g wet weight (w.w.), respectively). Merlin and Sparrowhawk eggs were the highest contaminated with chlorinated pesticides (average sum pesticide concentration: 3.0 and 4.3 microg/g w.w.). For the first time, the content of chlorobornanes was determined in Norwegian birds of prey eggs. However, only minor contamination compared to PCBs and conventional chlorinated pesticides was found. The highest sum concentration was determined for White-tailed Sea Eagle eggs (0.09 microg/g w.w.). No chlorobornane contamination was found in Osprey and Merlin eggs. No spatial and regional specific trends or pattern distribution were found for organochlorine contamination in the egg samples analysed. In order to gain information about enantiomer specific bioaccumulation and biotransformation capacity of the organism, enantioselective analyses was performed for the chiral contaminants trans-chlordane, oxy-chlordane and the chlorobornane B9-1679 (Parlar #50). Indications for species-dependent deviation from the racemic distribution (enantiomeric ratio = 1) were found. Peregrine Falcon and Merlin eggs were characterised with an extremely high enantiomeric excess of the (-)-trans-chlordane (enantiomeric ratio (ER) <0.01). For Golden Eagle, Goshawk and Sparrowhawk eggs, the ERs were between 0.1 and 0.22 demonstrating also here that the (-)-trans-chlordane was the most abundant enantiomer. For the distribution of oxy-chlordane and B9-1679 enantiomers no species-dependent differences were found. For all species the ER values between 0.3 and 0.8 were determined. Thus, also for oxy-chlordane and B9-1679, the (-)-enantiomers are the most dominating stereoisomers in the birds of prey eggs analysed.