Organics Core: International Research in Organic Compounds

            International Research in Organic Compounds:  Dr. Hauser is also conducting international research on children’s health. At the population level, epidemiologic studies suggest a temporal trend of earlier pubertal onset and longer duration of puberty, raising concerns regarding the potential impact of environmental factors on pubertal development. Although specific etiologies have not been clearly identified for this reported change in the age of pubertal onset, the effects of environmental chemicals on the reproductive axis, as well as the epidemic of obesity and over-nutrition have both been implicated as potential factors. Environmental chemicals and metals of particular concern are dioxins, polychlorinated biphenyls and lead. Using pilot funding from the Harvard-NIEHS Center to generate preliminary data, Dr. Hauser applied for and received a grant from the USEPA to conduct a prospective cohort study in Chapaevsk, Russia on the relationship of lead, PCBs and dioxins with somatic growth and pubertal development among male children.  The research team includes HSPH colleagues, Drs. Paige Williams and Susan Korrick. In 2006, they received five additional years of funding from NIEHS to continue follow-up of the cohort and to extend the study aims. Their Russian study represents one of the largest epidemiologic studies on environmental impacts on male pubertal development. Although challenging to conduct the study in Russia, the results will advance our understanding of chemical impacts on pubertal development.

The prospective cohort study includes 500 Russian boys recruited at eight- to nine- years of age. The specific research hypotheses include the investigation of the relationships of serum levels of lead and dioxins with the timing and tempo of pubertal development, the relationship of serum levels of lead and dioxins with linear growth, weight gain, body composition (percent body fat), and body mass index. They are also studying the relationship between lead and dioxins with altered measures of metabolism, including insulin resistance, dyslipidemia, and adipose tissue derived signaling hormones. Semen analyses on the children when they are eighteen years of age will allow an investigation of the relationship between testicular function and peri-pubertal exposure to dioxins.

Drs. Hauser and Duty received Center Pilot funding to incorporate an environmental component into a large international birth cohort study in the Netherlands where they are studying the relationship of pre-natal exposure to phthalates, pesticides and bisphenol A with pregnancy and childhood health endpoints. The Generation R study in the Netherlands is a prospective cohort study of 10,000 pregnant women. The study is designed to follow the children through early adulthood and explore relationships between pre-natal and childhood risk factors and the development of disease. The original design did not include the collection of biological samples for environmental chemical exposure assessment. They initiated a new collaboration with Dutch and NIEHS investigators to incorporate an environmental component in the study. The pilot funding enabled this collaboration.