On July 2, 2015 the peer-reviewed journal International Journal of Hygiene and Environmental Health published a study on the effects of exposure to endocrine disrupting chemicals (EDCs) on the physical development of adolescents. Researchers Jia-Woei Hou and colleagues, based at different medical institutions and universities in Taiwan, tested the urine of 308 adolescents for the metabolites of phthalates dimethyl phthalate (DMP, CAS 131-11-3), diethyl phthalate (DEP, CAS 84-66-2), dibutyl phthalate (DBP, CAS 84-74-2), diisobutyl phthalate (DIBP, CAS 84-69-5), benzylbutylphthalate (BBzP, CAS 85-68-7), and diethylhexyl phthalate (DEHP, CAS 117-81-7), as well as for nonylphenol (NP, CAS 104-40-5). 270 of the participants were “general” adolescents aged 6.5 to 15; 38 of the participants were adolescents affected by the Taiwanese phthalate-contaminated foods scandal of 2011 and aged 6.5 to 8.5. To assess body size, the researchers measured the anthropometric indices body mass index (BMI), weight, height, waist circumference (WC), hip circumference (HC), and skinfold thickness. Waist-to-height ratio (WHeightR) and waist-to-hip ratio (WHipR) were subsequently calculated. Further, the researchers used a questionnaire to evaluate pubertal maturity. Hou and colleagues observed a dose-response relationship between urinary phthalate metabolite concentrations and skinfold thickness, WC, WHeightR, and WHipR. These anthropometric indices are indicators for abdominal obesity. Urinary concentrations of monomethyl phthalate (MMP, CAS 4376-18-5), a metabolite of DMP, inversely correlated with pubarche in boys. No association between NP exposure and the anthropometric indices or pubertal maturity were observed. Interaction of co-exposure to NP and phthalates was also not correlated. Comparing the general and phthalate-affected adolescents, no significant differences were observed regarding BMI, weight, or height. Given their results, the researchers suggest that the reference doses and tolerable daily intake for phthalates need to be revised to provide sufficient protection.
Hou, J. W. et al. (2015). “The effects of phthalate and nonylphenol exposure on body size and secondary sexual characteristics during puberty.” International Journal of Hygiene and Environmental Health (available online July 2, 2015).