Endocrine Disruptors

Reproductive Toxicology

Pajak

Pinney

et al. 2017

To study potential environmental influences on puberty in girls, we investigated urinary biomarkers in relation to age at menarche. Phenols and phthalates were measured at baseline (6-8 years of age). Menarche was ascertained over 11 years for 1051 girls with menarche and biomarkers. Hazards ratios were estimated from Cox models adjusted for race/ethnicity and caregiver education (aHR, 95% confidence intervals [CI] for 5th vs 1st quintile urinary biomarker concentrations). 2,5-Dichlorophenol was associated with earlier menarche (aHR 1.34 [1.06-1.71]); enterolactone was associated with later menarche (aHR 0.82 [0.66-1.03]), as was mono-3-carboxypropyl phthalate (MCPP) ); the three p-trends were <0.05. Menarche differed by 4-7 months across this range. Enterolactone and MCPP associations were stronger in girls with below-median body mass index. These analytes were also associated with age at breast development in this cohort. Findings from this prospective study suggest that some childhood exposures are associated with pubertal timing.

Section: Introductionmentioning

confidence: 99%

Associations of urinary phthalate and phenol biomarkers with menarche in a multiethnic cohort of young girls

Reproductive Toxicology

Pajak

Pinney

et al. 2017

“…During the past 20 years, a new generation of environmental contaminants has emerged, including metabolites of chemicals used widely in commerce and derived from a variety of sources (Wolff, 2006). Human exposure exists universally, as documented by detection of urinary metabolites around the world (CDC, 2009; Moos et al , 2014; Philippat et al , 2012; Engel et al , 2014; Nahar et al , 2012; Xue et al , 2015).…”

Section: Introductionmentioning

confidence: 99%

Environmental phenols and pubertal development in girls

Environment International

Teitelbaum

McGovern

et al. 2015

109

Environmental exposures to many phenols are documented worldwide and exposures can be quite high (>1 micromolar of urine metabolites). Phenols have a range of hormonal activity, but knowledge of effects on child reproductive development is limited, coming mostly from cross-sectional studies. We undertook a prospective study of pubertal development among 1239 girls recruited at three U.S. sites when they were 6–8 years old and were followed annually for 7 years to determine age at first breast or pubic hair development. Ten phenols were measured in urine collected at enrollment (benzophenone-3, enterolactone, bisphenol A, three parabens (methyl-, ethyl-, propyl-), 2,5-dichlorophenol, triclosan, genistein, daidzein). We used multivariable adjusted Cox proportional hazards ratios (HR (95% confidence intervals)) and Kaplan-Meier survival analyses to estimate relative risk of earlier or later age at puberty associated with phenol exposures. For enterolactone and benzophenone-3, girls experienced breast development 5–6 months later, adjusted HR 0.79 (0.64–0.98) and HR 0.80 (0.65–0.98) respectively for the 5th vs 1st quintiles of urinary biomarkers (μg/g-creatinine). Earlier breast development was seen for triclosan and 2,5- dichlorophenol: 4–9 months sooner for 5th vs 1st quintiles of urinary concentrations (HR 1.17 (0.96–1.43) and HR 1.37 (1.09–1.72), respectively). Association of breast development with enterolactone, but not the other three phenols, was mediated by body size. These phenols may be antiadipogens (benzophenone-3 and enterolactone) or thyroid agonists (triclosan and 2,5- dichlorophenol), and their ubiquity and relatively high levels in children would benefit from further investigation to confirm these findings and to establish whether there are certain windows of susceptibility during which exposure can affect pubertal development.

“…This increase in scientific attention is in part because exposure to many of these chemicals was only recently recognized (15, 14, 88). In addition, technological advances in exposure measurement have provided human biomonitoring data for chemicals of interest, documenting widespread exposure internationally and across all age ranges (11).…”

Section: Introductionmentioning

confidence: 99%

Causal Inference Considerations for Endocrine Disruptor Research in Children's Health

Engel

Annu. Rev. Public Health

2013

Substantial population exposure to endocrine disrupting chemicals, combined with available biomarkers and public concern, has resulted in an explosion of human health effects research. At the same time, remarkable shifts in the regulations governing the composition of some consumer products that contain endocrine disruptors (EDs) has occurred. However, important questions remain as to the weight of evidence linking EDs to human health end points. In this review, we critically examine the literature linking ED exposures to child neurodevelopment, focusing in particular on two model exposures to demonstrate issues related to bioaccumulative [e.g., polychlorinated biphenyls (PCBs)] and rapidly metabolized (e.g., phthalates) compounds, respectively. Issues of study design, confounding, and exposure measurement are considered. Given widespread exposure to these compounds, the potential public health consequences of even small effects on human health are substantial. Therefore, advancing our understanding of any impact calls for careful attention to the principles of causal inference.