Concentrations of perfluoroalkyl substances in human milk from Ireland: Implications for adult and nursing infant exposure.

Concentrations of 10 perfluoroalkyl substances (PFASs) were measured in 16 pools of human milk from Ireland. Only four PFASs were detected (PFOA, PFNA, PFHxS and PFOS), with concentrations dominated by PFOA which was detected in all samples at a median of 0.10 ng/mL. Concentrations and the relative abundance of PFASs in human milk from Ireland are within the range reported for other countries. Estimated exposures for nursing infants to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) do not suggest a health concern. A one compartment pharmacokinetic model was used to predict the intakes of PFOS and PFOA required to support the observed concentrations in human milk. This suggests current adult exposure in Ireland to PFOS is below the provisional tolerable weekly intake (TWI) proposed by EFSA. In contrast, the model predicts that the maximum concentration detected in human milk in this study, implies a level of adult exposure that would exceed EFSA's provisional TWI for PFOA. As exposure of the Irish population to PFASs via drinking water, indoor air and dust is well-characterised, current understanding suggests that the major contributor to overall exposure of the Irish population is via the diet and/or less well-studied pathways like dermal uptake from PFAS-containing fabrics and cosmetics.

Emerging and legacy brominated flame retardants in the breast milk of first time Irish mothers suggest positive response to restrictions on use of HBCDD and Penta- and Octa-BDE formulations.

The brominated flame retardants (BFRs) hexabromocyclododecane (HBCDD), eight polybrominated diphenyl ethers (PBDEs), and decabromodiphenyl ethane (DBDPE) were measured in 16 pools of human milk from Ireland. Concentrations of BDEs-47, -99, -100, -153, and HBCDD were significantly lower (p < 0.05) than those in Irish human milk collected in 2011. In contrast, concentrations of BDE-209 in our study exceeded those in 2011, and while decabromodiphenyl ethane (DBDPE) was not detected in 2011 it was detected in 3 of our samples. This suggests increased use of DBDPE and that while restrictions on the Penta- and Octa-BDE formulations are reducing human exposure, those on Deca-BDE use have yet to reduce body burdens. Estimated exposures for nursing infants to all target BFRs do not suggest a health concern. A one compartment pharmacokinetic model was used to predict body burdens arising from BFR intakes via air, dust and diet. While for most targeted BFRs, predicted and observed body burdens derived from our human milk data compared reasonably well; predicted BDE-209 and DBDPE values were substantially lower than observed. This suggests exposure pathways not included in the model like dermal uptake from fabrics may be important, and highlights knowledge gaps about the human half-lives and bioavailability of these contaminants.

Perfluoroalkyl Substances in Drinking Water, Indoor Air and Dust from Ireland: Implications for Human Exposure.

Perfluoroalkyl substances (PFASs) were measured in air and dust from cars, homes, offices, and school classrooms in Ireland, along with drinking water from homes and offices. Perfluorooctanoic acid (PFOA) dominated air and drinking water, while perfluorobutane sulfonate (PFBS) dominated dust. This is the first report of PFOA, perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), PFBS, and perfluorononanoic acid (PFNA) in air inside cars and school classrooms. PFOS concentrations in classroom air exceeded significantly (p ≤ 0.05) those in homes. Atmospheric concentrations of PFOA, PFNA, and methyl perfluorooctane sulfonamido ethanol (MeFOSE) (p ≤ 0.05) were significantly higher in cars containing child car seats than in cars without. PFOS, PFOA, PFBS, and PFHxS were all detected frequently in drinking water, but concentrations of PFASs were low, and although ΣPFASs were 64 ng/L in one bottled water sample, this fell below a Swedish Action Level of 90 ng ΣPFASs/L. The Irish population's exposure to PFOS and PFOA via non-dietary sources is well below estimates of dietary exposure elsewhere in Europe. Moreover, even under a high-end exposure scenario, it falls below the European Food Safety Authority's (EFSA) provisional tolerable weekly intakes for PFOS and PFOA.

Concentrations of Brominated Flame Retardants in Indoor Air and Dust from Ireland Reveal Elevated Exposure to Decabromodiphenyl Ethane.

Concentrations of decabromodiphenyl ethane (DBDPE), 13 polybrominated diphenyl ethers (PBDEs), and hexabromocyclododecane (HBCDD) were measured in indoor air and dust collected from Irish homes, cars, offices, and primary schools during 2016-2017. Median concentrations of DBDPE in air (88 pg/m3) and dust (6500 ng/g) significantly exceed those previously reported internationally, with concentrations highest in offices and schools, suggesting that DBDPE is widely used in Ireland. Median concentrations of BDE-209 in air (340 pg/m3) and dust (7100 ng/g) exceed or are within the range of concentrations reported recently for the same microenvironments in the U.K., and exceed those reported in many other countries. Concentrations of BDE-209 in cars exceeded significantly (p < 0.05) those in other microenvironments. HBCDD was detected in all dust samples (median: 580 ng/g), and in 81% of air samples (median: 24 pg/m3) at concentrations similar to those reported recently for the U.K. and elsewhere. Estimates of exposure to DBDPE of Irish adults (92 ng/day) and toddlers (210 ng/day) as well as to BDE-209 (220 ng/day and 650 ng/day for adults and toddlers, respectively) substantially exceed those reported for the U.K. population. Moreover, our estimates of exposure of the Irish population to Σtrideca-PBDEs exceed previous estimates for Ireland via dietary exposure.