Prenatal and postnatal exposure to perfluoroalkyl substances and bone mineral content and bone mineral density in 9-year-old children from the Odense Child Cohort.

BACKGROUND

Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with lower bone mineral content (BMC) and density (BMD) in children, but prospective studies remain limited. We aimed to investigate associations between prenatal and childhood PFAS exposure and BMC/BMD at age 9 years, following up on our previous findings from age 7 years.

METHODS

We used data from the Odense Child Cohort, which enrolled pregnant women between 2010 and 2012 and followed their children. Five PFAS were measured in maternal first-trimester serum, and eight PFAS in child serum at 18 months and 5 years. Whole-body DXA scans were conducted at age 9 years. We used covariate-adjusted linear regression models and examined PFAS mixture effects using quantile g-computation. All models were stratified by child sex.

RESULTS

In this relatively low-exposed cohort, higher prenatal (n = 845) and childhood (n = 630 and n = 719) PFAS concentrations were associated with lower BMC and BMD Z-scores at age 9 years, although none of the estimates reached statistical significance. Generally, stronger associations were found in boys. Consistent with the single-pollutant models, mixture analyses indicated that maternal exposure to the PFAS mixture was significantly associated with a 4.86 g (-9.6; -0.13) reduction in BMC at age 9 years.

CONCLUSION

Our findings align with previous studies suggesting that bone may be a target tissue for PFAS, with effects that may persist over time. These findings raise public health concerns, as lower bone mass in childhood is associated with increased risk of osteoporosis and fractures in adulthood.