Per- and Polyfluoroalkyl Substance Plasma Concentrations and Bone Mineral Density in Midchildhood: A Cross-Sectional Study (Project Viva, United States).

BACKGROUND: Identifying factors that impair bone accrual during childhood is a critical step toward osteoporosis prevention. Exposure to per- and polyfluoroalkyl substances (PFASs) has been associated with lower bone mineral density, but data are limited, particularly in children. METHODS: We studied 576 children in Project Viva, a Boston-area cohort of mother/child pairs recruited prenatally from 1999 to 2002. We quantified plasma concentrations of several PFASs and measured areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) in midchildhood. We used linear regression to examine associations between plasma concentrations of individual PFASs and aBMD z-score. We used weighted quantile sum (WQS) regression to examine the association of the PFAS mixture with aBMD z-score. All models were adjusted for maternal age, education, annual household income, census tract median household income, and child age, sex, race/ethnicity, dairy intake, physical activity, and year of blood draw. RESULTS: Children were [[Formula: see text]] [Formula: see text] of age. The highest PFAS plasma concentrations were of perfluorooctanesulfonic acid (PFOS) {median [interquartile range (IQR)]: 6.4 (5.6) ng/mL} and perfluorooctanoic acid (PFOA) [median (IQR): 4.4 (3.2) ng/mL]. Using linear regression, children with higher plasma concentrations of PFOA, PFOS, and perfluorodecanoate (PFDA) had lower aBMD z-scores [e.g., [Formula: see text]: [Formula: see text]; 95% confidence interval (CI): [Formula: see text], [Formula: see text] per doubling of PFOA]. The PFAS mixture was negatively associated with aBMD z-score ([Formula: see text]: [Formula: see text]; 95% CI: [Formula: see text], [Formula: see text] per IQR increment of the mixture index). CONCLUSIONS: PFAS exposure may impair bone accrual in childhood and peak bone mass, an important determinant of lifelong skeletal health. https://doi.org/10.1289/EHP4918.

Findings of a Statewide Environmental Lead Inspection Program Targeting Homes of Children With Blood Lead Levels as Low as 5 µg/dL.

CONTEXT: There are limited data on the nature of environmental lead hazards identified during residential inspections for child blood lead levels (BLLs) of less than 10 µg/dL. We compare inspection findings for child BLLs of 5 to 9 µg/dL versus 10 µg/dL or more. DESIGN: We reviewed inspection reports in Maine from September 2016 to March 2018. We used continuity-adjusted or Fisher's exact test for categorical variables and Wilcoxon rank-sum tests for continuous variables to compare differences in child, family, household, and lead hazard characteristics between BLL categories (5-9 µg/dL vs ≥10 µg/dL). We used Spearman correlation coefficients to assess relationships between home surface lead dust measurements and BLLs. RESULTS: Of 351 residential inspections, 272 (77%) were for children with BLLs of 5 to 9 µg/dL. Children with BLLs of 5 to 9 µg/dL as compared with children with BLLs of 10 µg/dL or more were less likely to chew window sills and door frames (8% vs 21%; P = .01), but otherwise were similar with respect to other established risk factors for lead poisoning. Children with BLLs of 5 to 9 µg/dL tended to have fewer paint hazards inside their homes (64% vs 78%; P = .03), and they were more likely to have dust-only hazards (8% vs 3%) or no identified lead paint hazards (23% vs 15%), though these differences were not statistically significant. For children with BLLs of 5 to 9 µg/dL, BLL was weakly correlated with average window sill dust level (Spearman r = 0.16; P = .01) and average floor dust level (r = 0.13; P = .03), but these correlations were not observed for children with BLLs of 10 µg/dL and higher. CONCLUSIONS: We have found that inspections of homes of children with BLLs of 5 to 9 µg/dL are nearly as likely to identify lead hazards that require abatement as inspections of homes of children with BLLs of 10 µg/dL.