Scientists link chemical exposure to early puberty
ENN
Thursday, February 15, 2001
By Margot Higgins
According to researchers, chemicals in the environment may be the cause of early puberty for young girls. For some African-American girls, puberty may be accelerated by as much as two years.
Chemicals in the environment are contributing to the onset of early puberty in girls, a panel of scientific experts report.
Following a groundbreaking 1997 study by Marcia Herman-Giddens on 17,000 individuals, scientists and doctors have been aware that young girls are reaching puberty at a younger age.
| "By age 8, 48 percent of African-American girls and 15 percent of white girls have started developing breast and/or pubic hair, Herman-Giddens noted" |
Herman-Giddens' study, published in the journal Pediatrics, found that the initial signs of puberty are occurring earlier than previously recorded, — up to a year earlier in white girls and two years earlier in African-American girls.
By age 8, 48 percent of African-American girls and 15 percent of white girls have started developing breast and/or pubic hair, Herman-Giddens noted. Some girls begin the process as young as age 2.
Yet the causes of the hormonal fast-forward have been the subject of increasing debate.
"What we're seeing is a symptom of a very serious public health problem," said Herman-Giddens.
The chemical industry has fiercely objected to the idea that common chemicals such as those found in plastics are contributing to the phenomenon.
According to Pete Myers, the author of "Our Stolen Future," a combination of modern-day influences is responsible. Obesity, genetics, low birth weight and social surroundings are among the contributing factors that he and other experts have associated with early puberty.
Three lines of evidence confirm that chemical exposure is an important part of the puzzle, Myers said.
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In Puerto Rico, researchers found that eight in 1,000 children are afflicted with premature sexual development. Pictured here, a 2-year-old Puerto Rican girl.
Lab experiments with mice and rats show clearly that the rate of sexual development is vulnerable to pre-natal and post-natal chemical contamination. Data on human exposure has documented widespread exposure to some of the same contaminants that are producing effects in lab animals. Other data in humans shows an association between exposure to certain chemicals and changes in the rate of sexual development.
| "There is no question that everyone in America has been exposed to hormone-disrupting chemicals in the womb at varying levels." |
Certain chemicals such as bisphenol A, a basic building block of a variety of plastics including toys and baby bottles, have been shown to "mimic" the natural hormone estrogen, Myers notes.
"There is no question that everyone in America has been exposed to hormone-disrupting chemicals in the womb at varying levels. The amount of exposure depends on lifestyle, where we live, what we eat. Some of us have had more, some of us have had less, but none of us have had no exposure."
More worrisome, perhaps, than the physical effects of early puberty are the potential psychological effects that the experience can have.
Before they have outgrown doll houses, many young girls are being faced with the confusing mood swings, hormonal changes and sexual attention that accompany physical maturation.
Studies have found that girls who reach puberty earlier tend to have sex earlier, experience more psychological stress and are more likely to drink, smoke and commit suicide.
"Puberty is a tough time for all kids," said child psychologist Diana Zuckerman, director of the National Center for Policy Research on Women and Children. "This is changing what it means to be a child."
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