Associations between exposure to a mixture of phenols, parabens, and phthalates and sex steroid hormones in children 6-19 years from NHANES, 2013-2016.
Level 4 - case-series / case-control
Cross-sectional analysis of survey data (NHANES 2013–2016)
PubMed 35114227 · doi:10.1016/j.scitotenv.2022.153548
What was done
Researchers evaluated 1,179 U.S. children and adolescents aged 6–19 years from the National Health and Nutrition Examination Survey (NHANES) 2013–2016 with complete exposure and hormone data. Exposures included 7 environmental chemicals: 2 phenols (bisphenol A and bisphenol S), 2 parabens (methylparaben and propylparaben), and 3 phthalate metabolites (MBzP, MiBP, and MCOP). Outcomes measured were estradiol, total testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), and the testosterone-to-estradiol ratio. Analyses used linear regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR), stratified by pubertal status defined via hormone thresholds.
What was found
The abstract reports directions of association but provides no numerical effect estimates, confidence intervals, or p-values. Exposure to individual chemicals and chemical mixtures was generally negatively associated with estradiol, total testosterone, FAI, and the testosterone-to-estradiol ratio, and positively associated with SHBG. These associations were stronger in pubertal youth than in prepubertal youth. In WQS and BKMR mixture models, phthalate metabolites were identified as the most heavily weighted contributors to the observed associations.
Why it matters
Children are exposed to complex real-world chemical mixtures rather than isolated compounds. This study applies multi-pollutant statistical models showing that combined exposure to common consumer product chemicals, particularly phthalates, correlates with altered circulating reproductive hormones during puberty.
Limits
The study is cross-sectional, preventing any causal inference or determination of whether exposure preceded hormonal changes. The abstract does not provide exact effect sizes, standard errors, or p-values. Single-point biomonitoring measurements may not reflect long-term chronic exposure, and unmeasured confounders such as diet, diurnal hormone variation, or timing of biological sampling were not detailed.
Cited by
- partial Receipts are coated with BPA, and a study in adolescent boys showed BPA exposure was associated with a 50% reduction in testosterone.