Serum PFAS and Urinary Phthalate Biomarker Concentrations and Bone Mineral Density in 12-19 Year Olds: 2011-2016 NHANES

By Jenny L Carwile, Shravanthi M Seshasayee, Katherine A Ahrens, Russ Hauser, Jeffrey B Driban, Clifford J Rosen, Catherine M Gordon, and Abby F Fleisch
J Clin Endocrinol Metab
May 10, 2022
DOI: 10.1210/clinem/dgac228


Per- and polyfluoroalkyl substances (PFAS) and phthalates are two families of environmental endocrine disruptors that may be associated with areal lower bone mineral density (aBMD).


To examine associations between serum PFAS and urinary phthalate biomarker concentrations and their mixtures with aBMD Z-score in adolescents.

Design, Patients, And Measures

We examined serial cross-sectional data from male (n=453) and female (n=395) 12-19 year old participants in the 2011-2016 National Health and Nutrition Examination Survey with measures of serum PFAS, urinary phthalate metabolites, and dual-energy X-ray absorptiometry aBMD Z-score (total body less head). In sex-specific models, we used linear regression to examine associations of individual PFAS and phthalate biomarkers with aBMD Z-score, and Bayesian kernel machine regression (BKMR) to examine the association of the overall PFAS/phthalate biomarker mixture with aBMD Z-score. We replicated the analysis, stratifying by race/ethnicity.


Participants were (mean ± SD) 15 ± 2.1 years old. In males, each doubling of serum perfluorooctanoate (PFOA), perfluorooctane sulfonate rinary mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate, and the overall PFAS/phthalate mixture was associated with a lower aBMD Z-score (e.g., for PFOA: -0.24, 95% CI, -0.41, -0.06). Serum PFOA and urinary MiBP were associated with higher aBMD Z-score in females (e.g., for PFOA: 0.09, 95% CI, -0.07, 0.25). Findings did not differ by race/ethnicity.


Certain PFAS and phthalates may be associated with reduced bone mineral density in adolescent males. Bone mineral density tracks across the lifecourse, so if replicated in longitudinal cohorts, this finding may have implications for lifelong skeletal health.

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