Determinants of plasma concentrations of perfluoroalkyl substances in pregnant Norwegian women

Abstract

Background Perfluoroalkyl substances (PFASs) are widespread pollutants that have been associated with adverse health effects although not on a consistent basis. Diet has been considered the main source of exposure. The aim of the present study was to identify determinants of four plasma PFASs in pregnant Norwegian women. Methods This study is based in the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. Our sample included 487 women who enrolled in MoBa from 2003–2004. A questionnaire regarding sociodemographic, medical, and reproductive history was completed at 17 weeks gestation and a dietary questionnaire was completed at 22 weeks gestation. Maternal plasma samples were obtained around 17 weeks of gestation. Plasma concentrations of four PFASs (perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA)) were examined in relation to demographic, lifestyle, dietary, and pregnancy-related covariates. Predictors were identified by optimizing multiple linear regression models using Akaike’s information criterion (AIC). Results Parity was the determinant with the largest influence on plasma PFAS concentrations, with r2 between 0.09 and 0.32 in simple regression models. In optimal multivariate models, when compared to nulliparous women, parous women had 46%, 70%, 19%, and 62% lower concentrations of PFOS, PFOA, PFHxS, and PFNA respectively (p<0.001 except for PFHxS, p<0.01). In all these models, duration of breastfeeding was associated with reduced PFAS levels. PFOA showed the largest reduction from breastfeeding, with a 2–3% reduction per month of breastfeeding in typical cases. Levels of PFOS, PFOA, and PFNA increased with time since most recent pregnancy. While pregnancy-related factors were the most important predictors, diet was a significant factor explaining up to 4% of the variance. One quartile increase in estimated dietary PFAS intake was associated with plasma PFOS, PFOA, PFHxS, and PFNA concentration increases of 7.2%, 3.3%, 5.8% and 9.8%, respectively, resulting in small, although non-trivial absolute changes in PFAS concentrations. Conclusion The history of previous pregnancies and breastfeeding were the most important determinants of PFASs in this sample of pregnant women.

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

“…Independent of consumption group, women had lower PFOS and PFHxS concentrations than men, which is consistent with previous studies (Fromme et al, 2009). The effect of gender is probably a consequence of the enhanced elimination of PFASs via pregnancy, lactation, and menstruation Brantsaeter et al, 2013;Denys et al, 2014;Harada and Koizumi, 2009;Lorber et al, 2015;Salihovic et al, 2015;Wong et al, 2014). The lack of significant increasing trend across female consumption groups may be due to our small sample size combined with large individual variation.…”

“…Interestingly, serum PFOS concentrations in the high consumption group were two-fold higher than what has previously been reported in occupational firefighters around the world (Dobraca et al, 2015;Laitinen et al, 2014;Shaw et al, 2013), with the exception of Australian firefighters with concentrations 2-3 times higher than in our study (Rotander et al, 2015a(Rotander et al, , 2015b. Serum PFOS concentrations in the high consumption group were also in the higher range of previously reported values from Norway (Brantsaeter et al, 2013;Haug et al, 2009;Haug et al, 2010;Nost et al, 2014;Rylander et al, 2009;Rylander et al, 2010) as well as other parts of the world (Miralles-Marco and Harrad, 2015).…”

Examining confounding by diet in the association between perfluoroalkyl acids and serum cholesterol in pregnancy

“…Covariates were selected and included in our regression models were based on information provided in previous studies (Brantsaeter et al, 2013;Halldorsson et al, 2008). When examining the association between diet and serum PFOS and PFOA concentration the covariates included were maternal age and pre-pregnancy BMI.…”

Perfluoroalkyl substances (PFAS) including structural PFOS isomers in plasma from elderly men and women from Sweden: Results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS)

“…Breastfeeding has been found to be an important elimination factor of PFASs (Brantsaeter et al, 2013;Glynn et al, 2012;Sundström et al, 2011). Although the present study is unable to examine breastfeeding, the effect of parity among women of the same age could be used to gain more knowledge about internal PFAS exposure.…”