Grantee Research Project Results

1999 Progress Report: Environmental Exposures Related to Early Puberty

EPA Grant Number: R825816
Title: Environmental Exposures Related to Early Puberty
Investigators: Wolff, Mary S. , Kabat, Geoffrey , Forman, Joel , Britton, Julie , Leleiko, Neal , Hochman, Sarah , Larson, Signe , Kadlubar, Fred F. , Berkowitz, Gertrud S. , Godbold, James , Kase, Nathan
Current Investigators: Wolff, Mary S. , Kabat, Geoffrey , Forman, Joel , Britton, Julie , Leleiko, Neal , Hochman, Sarah , Larson, Signe , Kadlubar, Fred F. , Wetmur, James G. , Berkowitz, Gertrud S. , Godbold, James , Kase, Nathan , Serra, Nicole
Institution: Mount Sinai School of Medicine
EPA Project Officer: Aja, Hayley
Project Period: January 16, 1998 through January 15, 2001
Project Period Covered by this Report: January 16, 1998 through January 15, 1999
Project Amount: $380,482
RFA: Issues in Human Health Risk Assessment (1997) RFA Text |  Recipients Lists
Research Category: Environmental Justice , Human Health

Objective:

The goal of this research is to investigate the potential effect of cumulative, multiple environmental exposures on onset of puberty; in particular, early breast and hair development, which may be associated with estrogenic exposures. A secondary goal is to characterize the role of environmental exposures in racial/ethnic differences among girls as these exposures affect onset of puberty.

Our main hypothesis is that hormonally active exposures hasten onset of puberty (specifically, high levels of organochlorines and low levels of dietary isoflavones). Ancillary hypotheses are that environmental exposures are higher among girls from minority groups and that such exposures are mitigated by hormone-metabolizing enzymes.

Progress Summary:

Healthy 9-year-old girls from the Mount Sinai Pediatric Outpatient Clinic and the nearby Uptown Pediatric Practice were recruited from each of three ethnic groups (54 African-American, 66 Caucasian, 72 Hispanic). Both recent and usual dietary intake of phytoestrogen-containing foods, and potential confounders (height, weight, physical activity) were recorded. A blood sample was obtained to be analyzed for organochlorines (DDE, PCBs) and hormone-metabolizing genes, and spot urine samples to be analyzed for isoflavones were collected. We collected limited information on early life events (i.e., birth weight, mother's weight at birth); and further birth information was obtained from our hospital's neonatal data base and from birth certificates. The outcomes, pubertal stages of breast and hair development, are being modeled in relation to dietary factors, including food and nutrient intake and phytoestrogens. We have established a unique phytonutrient database to estimate phytoestrogen intake from the dietary questionnaire. Obesity and physical activity are also being examined as risk factors for puberty. Organochlorine analyses are still under way, but preliminary data show low levels (i.e., DDE in serum <2 ng/mL), but some variability in both DDE and PCBs.

Results to date show strong positive associations of pubertal onset with body mass index and African-American ethnicity. There is no effect of phytoestrogens (as lignans, isoflavones, flavonoids, and phytosterols) on pubertal onset; there is a significant effect of a very few food items and of three nutrients (vitamin C, saturated fat, magnesium) with pubertal onset, but the meaning of these associations is not yet clear. Analysis of phytoestrogens in urine has been completed, and there are some differences among ethnic groups. Relationships of urinary metabolites with pubertal onset are being examined. Differences are evident in physical activity among ethnic groups, but relationships with pubertal onset are not statistically significant. We have not yet completed the statistical analyses for birth outcomes and organochlorines. We have assessed variants in two hormone-metabolizing enzymes, and analyses are still under way for two additional enzymes.

Future Activities:

In the laboratory, the phytoestrogen and organochlorine analyses will be completed. Data analysis for these exposures as well as the birth events with respect to puberty will be undertaken, and publications prepared. Manuscripts are in preparation on Diet, ethnicity and pubertal onset, and on Physical Activity. An abstract has been submitted to the Society for Epidemiologic Research to be presented as a poster at the June 2000 meeting.

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this project

Supplemental Keywords:

puberty, ethnic, environmental exposures, hormones, diet, phytoestrogens, risk factors., Health, RFA, Scientific Discipline, Susceptibility/Sensitive Population/Genetic Susceptibility, Risk Assessments, Chemistry, genetic susceptability, Environmental Chemistry, Endocrine Disruptors - Human Health, Children's Health, endocrine disruptors, Genetics, health effects, toxicity, environmental mutagens, particle exposure models, toxic environmental contaminants, health risks, biological markers, environmental stressors, harmful environmental agents, age-related differences, growth & development, risk assessment, breast cancer, hispanics, human exposure, childhood cancer, diet, susceptibility, cumulative environmental exposure, fertility, adolescents, children, exposure, gender, reproductive effects, endocrine disrupting chemicals, age, reproductive, toxicants, environmental toxicant, gene-environment interaction, adolescence, reproductive health, isoflavones, developmental disorders, exposure assessment, human malformation, vulnerability, cancer risk, puberty, genetic diversity, interindividual variability, race ethnicity, subpopulations

Relevant Websites:

http://www.mssm.edu/cpm/cche.html

Progress and Final Reports:

Original Abstract

1998

Final Report