Mary S. Wolff, Ph.D., Susan Pinney, Ph.D.
Icahn School of Medicine at Mount Sinai
NIEHS Grants P01ES009584, U01ES012771, U01ES012770, U01ES012800, U01ES012801, U01ES019435, U01ES019453, U01ES019457, U01ES019454, P01ES009584, P30ES006096, P30ES023515
A new study finds that exposure to phenols, including some known endocrine disruptors, can affect the timing of pubertal development in girls. Early sexual maturation is associated with increased risk of breast cancer.
Although phenols are known to affect hormone activity, their effects on child reproductive development are not well studied. In the new study, researchers examined pubertal development among 1,239 girls who were enrolled in the Breast Cancer and the Environment Research Program Puberty Study between the ages of 6 and 8. The girls, from three U.S. sites, were followed annually for seven years to determine the age of first breast or pubic hair development. The researchers used urine collected at enrollment to measure ten phenols.
The analysis revealed that girls with the highest levels of enterolactone and benzophenone-3 experienced breast development five to six months later compared to those with the lowest levels, with adjusted hazard ratios of 0.79 (0.64–0.98) and 0.80 (0.65–0.98), respectively. Breast development four to nine months earlier was observed for girls with the highest levels of triclosan and 2,5-dichlorophenol, with adjusted hazard ratios of 1.17 (0.96–1.43) and 1.37 (1.09–1.72), respectively.
The researchers postulate that benzophenone-3 and enterolactone may block production of the hormone androgen and that triclosan and 2,5-dichlorophenol could affect thyroid hormones. Additional research is needed to confirm these findings and to identify any windows of susceptibility during which exposure might affect pubertal development.
Citation: Wolff MS, Teitelbaum SL, McGovern K, Pinney SM, Windham GC, Galvez M, Pajak A, Rybak M, Calafat AM, Kushi LH, Biro FM, Breast Cancer and Environment Research Program. 2015. Environmental phenols and pubertal development in girls. Environ Int 84:174-180.