Environmental phenols and pubertal development in girls

Area of Science:

• Environmental health
• Endocrinology
• Pediatric development

Background:

• Widespread environmental exposure to phenols is documented globally, with potentially high levels in children.
• Phenols possess diverse hormonal activities, yet their impact on child reproductive development remains understudied, primarily based on limited cross-sectional data.

Purpose of the Study:

• To prospectively investigate the association between urinary phenol concentrations and pubertal development timing in girls.
• To identify specific phenols that may influence the onset of breast and pubic hair development.

Main Methods:

• A prospective cohort study involving 1239 U.S. girls aged 6-8 years, followed annually for 7 years.
• Measurement of ten urinary phenols (e.g., benzophenone-3, enterolactone, bisphenol A, parabens, triclosan) at enrollment.
• Utilized Cox proportional hazards ratios and Kaplan-Meier analyses to assess risks of earlier or later puberty onset.

Main Results:

• Enterolactone and benzophenone-3 were associated with a 5-6 month delay in breast development.
• Triclosan and 2,5-dichlorophenol were linked to earlier breast development (4-9 months sooner).
• Body size mediated the association between enterolactone and breast development, suggesting potential antiadipogenic or thyroid-agonist roles for these phenols.

Conclusions:

• Certain ubiquitous environmental phenols show significant associations with altered pubertal timing in girls.
• Findings suggest potential antiadipogenic (benzophenone-3, enterolactone) and thyroid-agonist (triclosan, 2,5-dichlorophenol) mechanisms.
• Further investigation is warranted to confirm these results and identify critical windows of susceptibility for phenol exposure during development.