Concentrations of Per- and Polyfluoroalkyl Substances in Paired Maternal Plasma and Human Milk in the New Hampshire Birth Cohort.

Per- and polyfluoroalkyl substances (PFAS) are environmentally persistent endocrine-disrupting chemicals associated with long-term health outcomes. PFAS are transferred from maternal blood to human milk, an important exposure source for infants, and understanding of this transfer is evolving. We characterized concentrations of 10 PFAS in human milk (n = 426) and compared milk-to-plasma concentrations of 9 PFAS among a subset of women with paired samples (n = 294) from the New Hampshire Birth Cohort Study using liquid chromatography-isotope dilution tandem mass spectrometry. We examined the relationship between perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in plasma versus milk and fit linear regression models to assess relationships between milk PFOA and PFOS and participant characteristics. The median plasma PFOA concentration was 0.94 ng/mL (interquartile range, IQR, 0.59-1.34) and that of PFOS was 2.60 ng/mL (IQR 1.80-3.90); the median milk PFOA concentration was 0.017 ng/mL (IQR 0.012-0.027) and that of PFOS was 0.024 ng/mL (IQR 0.016-0.036). PFOA and PFOS plasma and milk concentrations showed correlations of ρ = 0.83 and 0.77, respectively (p < 0.001). Parity, previous lactation, week of milk collection, and body mass index were inversely associated with milk PFAS. We estimate that even among our general population cohort, some infants (∼6.5%) are exposed to amounts of PFAS via milk that may have long-term health impacts.

Quantifying levels of per- and polyfluoroalkyl Substances (PFAS) in water and serum after contamination from agricultural biosolid application.

The National Academies of Sciences, Engineering, and Medicine recommends per- and polyfluoroalkyl substance (PFAS) blood testing for patients with risk of elevated exposure, and the Agency for Toxic Substances and Disease Registry (ATSDR) suggests PFAS blood testing based on exposure. Barriers to PFAS blood testing include cost, access to labs, and evolving laboratory methods. We quantify water and serum PFAS levels among a highly-exposed cohort in an area with groundwater contaminated by historical agricultural biosolid application. We compare the gold standard PFAS serum test with a commercial test and results from a one-compartment toxicokinetic model. Participants were adults (n = 30) whose household (n = 19) water had levels of the sum of six PFAS > 500 ng/L. Serum PFAS were measured using liquid chromatography-tandem mass spectrometry. Demographic and water consumption data were collected via telephone. Serum PFAS results from the commercial test were accessed via medical record. Statistical analysis included descriptive statistics and bivariate plots of serum levels. Perfluorohexanoic acid, perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorobutanesulfonic acid, perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) were detected in 19 wells, and PFHpA, PFOA, PFNA, perfluorodecanoic acid, perfluoroundecanoic acid, PFHxS, and PFOS were detected in at least 19 participants' serum. In well water, PFOA and PFOS levels had geometric means (GMs) of 1749 ng/L (geometric standard deviation [GSD] 2.4) and 887 ng/L (GSD 19.7), respectively. In serum, PFOA and PFOS had GMs of 116.2 µg/L (GSD 13.5) and 58.3 µg/L (GSD 13.8), respectively. Our results are comparable with and had a wider mix of PFAS than other high-exposure cohorts. There was good agreement between the commercial and gold standard tests for PFOA, PFNA, and PFHxS, and mixed agreement between the gold standard test and modeled predictions, suggesting water-based toxicokinetic models of serum PFAS may be inadequate for assessing exposure in this population.

Association of diet with per- and polyfluoroalkyl substances in plasma and human milk in the New Hampshire Birth Cohort Study.

Per- and polyfluoroalkyl substances (PFAS) are related to various adverse health outcomes, and food is a common source of PFAS exposure. Dietary sources of PFAS have not been adequately explored among U.S. pregnant individuals. We examined associations of dietary factors during pregnancy with PFAS concentrations in maternal plasma and human milk in the New Hampshire Birth Cohort Study. PFAS concentrations, including perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), and perfluorodecanoate (PFDA), were measured in maternal plasma collected at ∼28 gestational weeks and human milk collected at ∼6 postpartum weeks. Sociodemographic, lifestyle and reproductive factors were collected from prenatal questionnaires and diet from food frequency questionnaires at ∼28 gestational weeks. We used adaptive elastic net (AENET) to identify important dietary variables for PFAS concentrations. We used multivariable linear regression to assess associations of dietary variables selected by AENET models with PFAS concentrations. Models were adjusted for sociodemographic, lifestyle, and reproductive factors, as well as gestational week of blood sample collection (plasma PFAS), postpartum week of milk sample collection (milk PFAS), and enrollment year. A higher intake of fish/seafood, eggs, coffee, or white rice during pregnancy was associated with higher plasma or milk PFAS concentrations. For example, every 1 standard deviation (SD) servings/day increase in egg intake during pregnancy was associated with 4.4 % (95 % CI: 0.6, 8.4), 3.3 % (0.1, 6.7), and 10.3 % (5.6, 15.2) higher plasma PFOS, PFOA, and PFDA concentrations respectively. Similarly, every 1 SD servings/day increase in white rice intake during pregnancy was associated with 7.5 % (95 % CI: -0.2, 15.8) and 12.4 % (4.8, 20.5) greater milk PFOS and PFOA concentrations, respectively. Our study suggests that certain dietary factors during pregnancy may contribute to higher PFAS concentrations in maternal plasma and human milk, which could inform interventions to reduce PFAS exposure for both birthing people and offspring.

Early-life exposure to per- and polyfluoroalkyl substances and infant gut microbial composition.

Human milk is rich in essential nutrients and immune-activating compounds but is also a source of toxicants including per- and polyfluoroalkyl substances (PFAS). Evidence suggests that immune-related effects of PFAS may, in part, be due to alterations of the microbiome. We aimed to identify the association between milk PFAS exposure and the infant gut microbiome. Methods: PFAS [perfluorooctane sulfonic acid (PFOS) and perfluorooctanoate (PFOA)] were quantified in milk from ~6 weeks postpartum using high-performance liquid chromatography with tandem mass spectrometry. A molar sum (ΣPFAS) was calculated. Caregivers collected infant stool samples at 6 weeks (n = 116) and/or 1 year postpartum (n = 119). Stool DNA underwent metagenomic sequencing. We estimated the association of PFAS with diversity and relative abundances of species with linear regression. Single- and multi-PFAS models adjusted for potential confounders in complete case analyses and with imputed missing covariate data for 6-week and 1-year microbiomes separately. We assessed sensitive populations with stratification. Results: PFOS and PFOA were detected in 94% and 83% of milk samples, respectively. PFOS was associated with increased diversity at 6 weeks among infants fed exclusively human milk [ß = 0.24 per PFOS doubling, (95% CI = 0.03, 0.45), P = 0.03] and born to primiparous mothers [ß = 0.37 (0.06, 0.67), P = 0.02]. Estimates were strongest in multi-PFAS models and among complete cases. ΣPFAS was associated with Bacteroides vulgatus relative abundance at 1 year [(ß = -2.34% per doubling (-3.63, -1.05), FDR q = 0.099]. Conclusions: PFAS may increase infant gut microbiome diversity and alter the relative abundance of biologically relevant bacteria. Additional analyses may identify related health outcomes.

Predictors of Human Milk Fatty Acids and Associations with Infant Growth in a Norwegian Birth Cohort.

Triglyceride-bound fatty acids constitute the majority of lipids in human milk and may affect infant growth. We describe the composition of fatty acids in human milk, identify predictors, and investigate associations between fatty acids and infant growth using data from the Norwegian Human Milk Study birth cohort. In a subset of participants (n = 789, 30% of cohort), oversampled for overweight and obesity, we analyzed milk concentrations of detectable fatty acids. We modelled percent composition of fatty acids in relation to maternal body mass index, pregnancy weight gain, parity, smoking, delivery mode, gestational age, fish intake, and cod liver oil intake. We assessed the relation between fatty acids and infant growth from 0 to 6 months. Of the factors tested, excess pregnancy weight gain was positively associated with monounsaturated fatty acids and inversely associated with stearic acid. Multiparity was negatively associated with monounsaturated fatty acids and n-3 fatty acids while positively associated with stearic acid. Gestational age was inversely associated with myristic acid. Medium-chain saturated fatty acids were inversely associated with infant growth, and mono-unsaturated fatty acids, particularly oleic acid, were associated with an increased odds of rapid growth. Notably, excessive maternal weight gain was associated with cis-vaccenic acid, which was further associated with a threefold increased risk of rapid infant growth (OR = 2.9, 95% CI 1.2-6.6), suggesting that monounsaturated fatty acids in milk may play a role in the intergenerational transmission of obesity.