Brominated Flame Retardants and Other Persistent Organohalogenated Compounds in Relation to Timing of Puberty in a Longitudinal Study of Girls.
Windham GC, Pinney SM, Voss RW, Sjodin A, Biro FM, Greenspan LC, Stewart S, Hiatt RA, Kushi LH.
Environmental Health Perspective, 2015 May 8, Epub ahead of print
Lay Abstract
One of the main goals of the Breast Cancer and the Environment Research Program (BCERP) is to study whether exposure to chemicals that are thought to have hormone-like effects (also known as endocrine disrupting chemicals, or EDCs) could affect the timing of puberty in girls. In this paper, we examine several classes of EDCs that persist in our environment for years; chemicals like DDT/DDE and other persistent pesticides, PCBs, and PBDEs (a group of fire retardants).
These chemicals were measured in the blood samples of more than 600 girls, 6-9 years old, who are participants at two of the BCERP study sites. The girls were seen once or twice per year, depending on the site, for up to 7 years. At these visits, information on many factors was collected and a physical exam was conducted to measure body size and the stage of puberty (breast and pubic hair development). Generally, we found that girls with higher chemical concentrations in their blood entered puberty later. Median differences in age at puberty were about 5-11 months older in girls with chemical levels in the top 25% compared to those in the bottom 25%. The findings varied somewhat by the body size (e.g. BMI) of the girl, which is known to be related to pubertal timing. When BMI was taken into account, there was less difference in age at puberty for girls with higher versus lower PCB and pesticide levels. Differences in age at puberty for girls with higher vs. lower PBDEs levels were not changed by accounting for BMI.
Finding a delay in puberty in girls with higher chemical exposure does not help explain the general trend of younger age at puberty. However, it does suggest that exposure to chemicals, during a stage of rapid growth and hormonally-driven changes, has an effect on the body’s development, which may in turn influence later health endpoints.
Dr. Gayle Windham can be reached at: EHIB, CA Dept. of Public Health, 850 Marina Bay Parkway, Building P, Richmond, CA 94804. e-mail: [email protected].
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