A major challenge of non-invasive human biomonitoring using hair is to assess whether it can be used as an indicator of exposure to Flame Retardants, such as Organophosphate Flame Retardants (PFRs), since the contribution of atmospheric deposition (air and/or dust) cannot be neglected. Therefore, the aim of this study was to evaluate the suitability of using human hair more thoroughly by comparison of (i) levels of PFRs in human hair (from 48 mothers and 54 children), with levels measured in dust and air in their respective households; and (ii) levels of selected PFRs in hair with the levels of corresponding PFR metabolites in matching urine samples collected simultaneously. Most PFRs (tri-n-butyl phosphate (TNBP), 2-ethyl-hexyldiphenyl phosphate (EHDPHP), tri-phenyl phosphate (TPHP), tri-iso-butyl phosphate (TIBP), and tris(2-butoxyethyl) phosphate (TBOEP)) were detected in all human hair samples, tris(2-ethylhexyl) phosphate (TEHP) and tris(1,3-dichloro-iso-propyl) phosphate (TDCIPP) in 93%, tri-cresyl-phosphate (TCP) in 69% and tris(2-chloroethyl) phosphate (TCEP) in 21% of the samples. Levels of individual PFRs ranged between
Exposure to persistent organic pollutants (POPs) during prenatal and postnatal life has been extensively studied in relation to adverse health effects in children.
The aim was to identify determinants of the concentrations of polychlorinated biphenyls (PCBs), brominated flame retardants (polybrominated diphenyl ethers, PBDEs; polybrominated biphenyl, PBB), and organochlorine pesticides (OCPs) in blood samples from pregnant women and children in The Norwegian Mother and Child Cohort Study (MoBa).
Blood samples were collected from two independent subsamples within MoBa; a group of women (n=96) enrolled in mid-pregnancy during the years 2002-2008 and a group of 3 year old children (n=99) participating during 2010-2011. PCB congeners (74, 99, 138, 153, 180, 170, 194, 209, 105, 114, 118, 156, 157, 167, and 189), brominated flame retardants (PBDE-28, 47, 99, 100, 153, 154, and PBB-153), as well as the OCPs hexachlorobenzene (HCB), oxychlordane, 4,4'dichlorodiphenyltrichloroethane (DDT), and 4,4'dichlorodiphenyldichloroethylene (DDE) were measured in both pregnant women and children.
Age, low parity, and low pre-pregnant BMI were the most important determinants of increased plasma concentrations of POPs in pregnant women. In 3 year old children, prolonged breastfeeding duration was a major determinant of increased POP concentrations. Estimated dietary exposure to PCBs during pregnancy was positively associated with plasma concentrations in 3 year old children, but not in pregnant women. Plasma concentrations were approximately 40% higher in children compared to pregnant women.
Several factors associated with exposure and toxicokinetics, i.e. accumulation, excretion and transfer via breastmilk of POPs were the main predictors of POP levels in pregnant women and children. Diet, which is the main exposure source for these compounds in the general population, was found to predict PCB levels only among children. For the PBDEs, for which non-dietary sources are more important, toxicokinetic factors appeared to have less predictive impact.
We analysed levels of 56 organohalogen contaminants (OHCs) including brominated flame retardants, polychlorinated biphenyls (PCBs), and organochlorine pesticides in the blubber of white (beluga) whales (Delphinapterus leucas) from Svalbard, Norway (N=12; 6 adults [5 males and 1 female] and 6 subadults [4 males and 2 females]) collected in 1996-2001. We also measured circulating levels of thyroid hormones (THs) and thyroid stimulating hormone (TSH) in the whales. The results confirm that OHC levels in these white whales are among the highest levels recorded in wildlife from Svalbard, and at the high end of the range when compared to white whales from the North American Arctic. A projection to latent structure (PLS) model (subadults and adult males grouped together) revealed that known or suspected thyroid disruptive contaminants (polybrominated diphenylether [PBDE]-28, -47, -99, -100, and -154, hexachlorobenzene [HCB], and PCB-105) were negatively correlated with circulating levels of total thyroxin (TT4), free T4 (FT4) and free triiodothyronine (FT3). Most of these negative relationships were also confirmed using partial correlations controlling for length (and thus age) of the whales. The positive correlations of TT4, FT4 and FT3 with hexabromocyclododecane (HBCD), a-hexachlorocyclohexane (a-HCH), chlorinated bornanes CHB-40 and CHB-62 revealed by the PLS model were not confirmed by partial correlations. TH levels in the present study appeared to be somewhat lower than levels measured in beluga whales from the Canadian Arctic. However, we were not able to determine if this was caused by different levels of OHCs, or differences in biological factors (e.g. age, sex, moulting status, and season) and analytical methods between the studies. Although the sample sizes were low and statistical models cannot depict the biological cause-effect relationships, this study suggests negative influences of specific OHCs, particularly PBDEs, on thyroid hormone levels in white whales. The impact this might have on individual and population health is unknown.
Food Research Division, Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, 251 Sir Frederick Banting Driveway, 2203C, Tunney's Pasture, Ottawa, ON K1A 0K9, Canada. Electronic address: firstname.lastname@example.org.
Detectable concentrations of the flame retardant hexabromocyclododecane (HBCD) have been reported in human tissues worldwide, but investigations to determine fetal exposure to this brominated flame retardant are lacking. This study was undertaken to determine the concentrations of a-, ß- and ?-HBCD in human tissues (fetal liver and placenta) from Canada. Tissue samples were collected over a thirteen year period following elective pregnancy terminations in Montreal, Quebec, Canada. Samples were extracted using homogenisation with solvent, cleaned up using adsorption chromatography and analysis was performed with liquid chromatography-tandem mass spectrometry. Total HBCD concentrations ranged from below the limit of detection (
Polybrominated diphenyl ethers (PBDEs), widely used as flame retardants in commercial products, have become ubiquitous environmental contaminants. Although adult human exposure to PBDEs is well documented, developmental exposure is less well characterized. The objectives of this study were to measure maternal and fetal exposure to nine PBDE congeners and to investigate potential associations with birth weight. PBDE congeners were quantified in maternal serum at 24-28 weeks of pregnancy, delivery, and umbilical cord serum (UCS) by gas chromatography-mass spectrometry (GC/MS/MS). Complete blood sample sets were obtained from 97 pregnant women (mean age 33.1±0.5 years). PBDE-28, -47 and -99 were quantified in all samples tested and PBDE-47 was the most abundant congener measured in both maternal (mid-pregnancy and delivery samples geometric mean=26.9 and 26.9, respectively) and UCS (GM=56.0 ng g(-1) lipid). The UCS concentration for all congeners with the exception of PBDE-153 was higher vs. maternal delivery samples (p
Commercial decabromodiphenyl ether (DecaBDE) is commonly used as a flame retardant in different electrical and textile applications. It is also used in the production of flame-retarded rubber compound. DecaBDE is the major technical polybrominated diphenyl ether (PBDE) in use today and consists mainly of decabromodiphenyl ether (BDE-209). PBDEs, including BDE-209, are well-known environmental pollutants, ubiquitous both in aquatic and terrestrial environments. The aim of the present study was to assess the exposure to PBDEs in workers manufacturing or handling rubber which was flame retarded with DecaBDE. A referent group, abattoir workers (slaughterhouse workers), with no occupational exposure to PBDEs, was also investigated. Moreover, the methodology for analysis of PBDEs in serum was refined, with special emphasis on congeners with a high number of bromine substituents, i.e., octa- to decaBDEs. The highest BDE-209 concentration observed among the rubber workers was 280 pmol/g lipid weight (I.w.) (270 ng/g I.w.). The median concentration of BDE-209 among rubber workers was 37 pmol/g I.w. (35 ng/g I.w.). Among referents, the median was 2.5 (range 0.92-9.7) pmol/g I.w. (median 2.4 ng/g I.w.). In rubber workers the BDE-209 concentrations were up to 32% (median 4%) of the 2,2',4,4',5,5'-chlorobiphenyl (CB-153) concentrations, on a molar basis, whereas the referents had BDE-209 concentrations which were similar to that of 2,2',4,4'-bromodiphenyl ether (BDE-47), below 1.4% (median 0.3%) of the CB-153 concentration. Concentrations of all nonabromodiphenyl ethers (nonaBDEs) and several octabrmodiphenyl ethers (octaBDEs) congeners, including BDE-203, were also elevated among the rubber workers, with 2.5- to 11-fold higher median concentrations, compared to the referents. The results confirm a significant uptake of BDE-209 in the workers exposed to DecaBDE and indicate a potential for in vivo formation of lower BDEs in these persons.
The levels and congener patterns of PBDEs were investigated in human placental samples in Denmark. The median concentrations of sigmaPBDE(tri-hepta) and BDE-209 in the 50 samples were 1.22 and 1.14 ng g(-1) lw, respectively, with the total sum ranging from 0.51 to 17.1 ng g(-1) lw, which is similar to previous placental studies. The PBDE content in placental tissue was dominated by BDE-209, which accounted for approximately 50% of the total amount of PBDEs. BDE-47, -99, and -153 were detected in all samples. Approximately equal amounts of BDE-47 and BDE-153 were observed in the placental tissue, which is in agreement with previous European studies of human serum. Principal Component Analysis (PCA) was performed to analyze congener patterns within and between mothers. The loading plot showed groupings of the measured PBDE variables in three groups, representative of Penta-, Octa- and Deca-BDE technical mixtures. Congeners representing the individual technical mixtures were close to orthogonal or inversely correlated, indicating variation in the congener patterns of internal exposure corresponding to the patterns of technical mixtures used in products. Visualisation of the participant objects according to body mass index (BMI), revealed inherent congener patterns (19% X-variance) showing increased frequency for participants within the highest BMI group to have elevated concentrations of BDE-209 in the placental tissue.
The UV-vis and infrared absorption cross sections of perfluoro-2-methyl-3-pentanone (CF3CF2C(O)CF(CF3)2, 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-penta none), has been obtained, and a photolysis study was carried out under natural sunlight conditions in the European simulation chamber, Valencia, Spain (EUPHORE). The photolysis loss rate, J(photol), equaled (6.4 +/- 0.3) x 10(-6) s(-1) in the period of 10-14 GMT, July 14, 2003 in Valencia (0.5 W, 39.5 N) and corresponded to an effective quantum yield of photolysis of 0.043 +/- 0.011 over the wavelength range of 290-400 nm; the error limits correspond to 2sigma from the statistical analyses. The atmospheric lifetime of CF3CF2C(O)CF(CF3)2 is estimated to be around 1 week, and the global warming potential of the compound is negligible.
PBDEs are being released to the environment in wastes from their production facilities, degradation, or leaching and volatilization from products that contain PBDEs during the product's useful life. Brominated diphenyl ether congeners BDE-47, -99, and -153 are ubiquitous in the environment and are regarded as the most dominant congeners present in wildlife and humans. The tetra- to hexa-BDE are most likely the congeners to which humans are exposed through food consumption. Knowledge of PBDE uptake, metabolism, elimination, and enzyme induction is restricted largely to rodents (rats and mice) in vitro and in vivo. Feeding studies have shown that excretion of higher brominated BDEs is much greater than lower brominated BDEs. Penta-BDE is more toxic than octa- and deca-BDE following oral administration (oral LD50 in rats, 0.5-5 g/kg). In rodents, repeated exposure to PBDEs results in thyroid hormone disruption, developmental neurotoxicity, some changes of fetal development, and hepatotoxic effects. The observed chronic NOELs depend upon the technical mixture type (i.e., deca-, octa-, or penta- and their congener composition), animal species, and study protocol. Values range from 0.6 to 100 mg/kg in rats and from I to 100 mg/kg in mice. PBDEs are neither mutagenic nor genotoxic. Immunotoxicity in mice is observed following exposure to BDE-47 at 18 mg/kg/d, where splenocyte number decreased. Mice exposed neonatally to a single oral dose of BDE-47(10.5 mg/kg) or BDE-99 (12 mg/kg) on Pnd10 (period of rapid brain growth and development) show permanent impairment of spontaneous motor behavior when reaching adulthood. BDE-99 also induced adverse effects on learning and memory functions of mice. The estimated daily intake based on food consumption for PBDEs ranges from 44 to 51 ng/d, with fish contributing almost one-half. The BDE-99 body burden from a human milk survey can be estimated at 0.64 microg/kg, well below the experimental body burden of 0.4 mg/kg BDE-99 associated with behavioral alterations in neonatal mice. When considering the outlier value for PBDE-99 at 229 ng/g, this would result in an estimated PBDE-99 body burden of 46 microg/kg, or a MOS of only 9. However, no toxicokinetics data are available for humans, and the actual margin of safety may be much smaller if based on levels in critical target organs or tissues.
Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montreal, QC H3C 3P8, Canada. Electronic address: email@example.com.
Despite a sustained effort in surveying flame retardants (FRs) in wildlife from industrialized regions, their occurrence in birds or any other wildlife species spanning the Arctic regions, particularly in North America, has received limited attention. This study investigated in the top predator glaucous gull (Larus hyperboreus) breeding in the Eastern Canadian Arctic (Cape Dorset, Nunavut) a comprehensive suite of FRs including unstudied halogenated and non-halogenated FRs of potential health concern, along with legacy organochlorines and mercury. The influence of diet acquired locally and in wintering areas on the tissue contaminant profiles was also investigated using d15N and d13C signatures in liver and feathers. The principal constituent in the Deca-brominated diphenyl ether (BDE) mixture, BDE-209, was remarkably the most concentrated PBDE congener determined in liver samples of Eastern Canadian Arctic glaucous gulls. This suggests dietary exposure from the local marine food web and perhaps also from nearby community landfills. Moreover, this study revealed for the first time the presence of 16 emerging halogenated and non-halogenated FRs in glaucous gulls from this Arctic region including HBB, DDC-CO (anti and syn isomers), PBEB, EHTBB, BEHTBP as well as a series of organophosphate esters (OPEs) (TCEP, TCIPP, TPP, TDCIPP, TDBPP, TBNP, TBOEP, TBEP, TCrP, EHDPP, and TEHP). With the exception of BDE-209, concentrations of other halogenated FRs and organochlorines were found to be in the lower range in liver of Eastern Canadian Arctic glaucous gulls compared to individuals from other circumpolar populations (Svalbard and Greenland). Mercury and methylmercury concentrations, however, were greater than reported elsewhere for glaucous gull populations.