Perfluoroalkyl Acids (PFAAs) in Children's Serum and Contribution from PFAA-Contaminated Drinking Water
Irina Gyllenhammar1, Jonathan P Benskin2, Oskar Sandblom2
1Department of Risk and Benefit Assessment , National Food Agency , P.O. Box 622, SE-751 26 Uppsala , Sweden.
Insights
Serum concentrations of per- and polyfluoroalkyl substances (PFAS) in children are linked to maternal levels, breastfeeding, and contaminated drinking water. Early life exposure to PFOA, PFHxS, and PFOS significantly impacts children
Area of Science:
- Environmental Health Sciences
- Toxicology
- Pediatric Environmental Exposure
Background:
- Per- and polyfluoroalkyl acids (PFAAs) are persistent environmental contaminants.
- Children may be exposed to PFAAs through various pathways including placental transfer, breastfeeding, and contaminated drinking water.
- Understanding exposure routes is crucial for assessing health risks in pediatric populations.
Purpose of the Study:
- To investigate associations between serum PFAA concentrations in children and exposure routes.
- To determine the influence of placental transfer, breastfeeding, and drinking water ingestion on PFAA levels in children.
- To identify which PFAAs and exposure pathways are most significant in a Swedish pediatric cohort.
Main Methods:
- Serum samples were collected from children aged 4, 8, and 12 years in Uppsala County, Sweden.
- PFAA concentrations (PFBS, PFHxS, PFOS, PFHpA, PFOA, PFNA) were measured in children's and mothers' serum.
- Statistical analyses assessed associations between serum PFAAs and exposure via maternal transfer, breastfeeding, and drinking water consumption.
Main Results:
- Perfluorooctanesulfonate (PFOS) had the highest median serum concentrations in children, followed by perfluorohexanesulfonate (PFHxS) and perfluorooctanoate (PFOA).
- Maternal serum levels at delivery were positively associated with children's serum PFOA, PFHxS, and PFOS, with stronger effects in younger children.
- Breastfeeding and contaminated drinking water were significant exposure sources, particularly for PFBS, PFHxS, PFOS, and PFOA, with drinking water showing a substantial impact for PFBS.
Conclusions:
- Early life exposure to PFOA, PFHxS, and PFOS significantly determines serum concentrations in children, especially at younger ages.
- Placental transfer, breastfeeding, and contaminated drinking water are key contributors to PFAA body burden in children.
- Even low to moderate contamination of drinking water with PFBS, PFHxS, PFOS, and PFOA represents an important exposure source for children.
Abstract:
We investigated associations between serum perfluoroalkyl acid (PFAA) concentrations in children aged 4, 8, and 12 years (sampled in 2008-2015; n = 57, 55, and 119, respectively) and exposure via placental transfer, breastfeeding, and ingestion of PFAA-contaminated drinking water. Sampling took place in Uppsala County, Sweden, where the drinking water has been historically contaminated with perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), perfluoroheptanoate (PFHpA), and perfluorooctanoate (PFOA). PFOS showed the highest median concentrations in serum (3.8-5.3 ng g-1 serum), followed by PFHxS (1.6-5.0 ng g-1 serum), PFOA (2.0-2.5 ng g-1 serum), and perfluorononanoate (PFNA) (0.59-0.69 ng g-1 serum) in children. Including all children, serum PFOA, PFHxS, and PFOS concentrations in children increased 10, 10, and 1.3% (adjusted mean), respectively, per unit (ng g-1 serum) of increase in the maternal serum level (at delivery), the associations being strongest for 4 year-old children. PFHxS and PFOS significantly increased 3.9 and 3.8%, respectively, per month of nursing, with the highest increase for 4 year-olds. PFOA, PFBS, PFHxS, and PFOS increased 1.2, 207, 7.4, and 0.93%, respectively, per month of cumulative drinking water exposure. Early life exposure to PFOA, PFHxS, and PFOS is an important determinant of serum concentrations in children, with the strongest influence on younger ages. Drinking water with low to moderate PFBS, PFHxS, PFOS, and PFOA contamination is an important source of exposure for children with background exposure from other sources.
