There have been numerous articles lately in scientific journals about the average age of puberty decreasing in American girls. Richard H. Reindollar, M.D. – Professor and Chair, Department of Obstetrics and Gynecology, Dartmouth Hitchcock Medical Center, Dartmouth Medical School, Lebanon, New Hampshire and his colleagues, for example, wrote on Endotext.org’s website, an international source of information for physicians, overall incidence of sexual precocity has been estimated to be 1:5,000 to 1:10,000 children. The female to male ratio is approximately 10:1
The classic definition of sexual precocity is the appearance of secondary sexual characteristics before the age of 8 years. The phenomenon was revealed in a study published in 1997 by a research team led by Dr. Herman-Giddens. Pediatricians around the country rated sexual maturation in 17,077 girls ages 3 to 12. The study’s conclusion was breasts and/or pubic hairs were far more common in 7- and 8-year-olds than medical textbooks had been reporting.
The scientists now studying premature sexual maturation in girls are mostly blaming it on children being overweight. The scientists point out fat releases hormones which could lead to premature puberty.
Dr. Frank Brio, the director of adolescent medicine at Cincinnati Children’s Hospital Medical Center, was quoted in the NY Times as agreeing that overweight girls were more likely to have breast development but added it was possible that environmental chemicals were also playing a role.
“It’s certainly throwing up a warning flag,” Dr. Biro said. “I think we need to think about the stuff we’re exposing our bodies to and the bodies of our kids. This is a wake-up call, and I think we need to pay attention to it.”
What chemicals in the environment may affect hormones?
So-called Endocrine Disrupting Compounds (EDC’s) are chemicals that mimic the body’s natural hormones, according to JA. Katzenellenbogen, professor of chemistry at the University of Illinois, writing in Environmental health in 1995: “They are environmental agents that interfere with the production, release, transport, metabolism, binding, action or elimination of natural hormones in the body responsible for the maintenance of homeostasis and the regulation of developmental processes.”
There have been many reports about EDCs adversely affecting sperm production in male and causing birth defects in male fetuses. David Norris, PhD, an integrative physiology professor at the University of Colorado at Boulder, for example, recently reported at the 92nd Endocrine Society’s meeting in San Francisco fish swimming in polluted waters may be the “canaries” alerting humans about endocrine disrupters. He says that even though the levels of the chemicals in waters fish swam in were very low, the substances proved to be endocrine disrupters.
How do EDCs Get In our Water?
One of the answers to EDCs in water may be our use of Personal Care Products. In 2008 a study carried out on behalf of the Environmental Working Group (EWG) claimed that 95 percent of the waterways in the San Francisco Bay area were contaminated with EDCs traced to personal care products.
In March 2009, still another study from the Baylor University showed that fish samples from US waterways are frequently contained residues of personal care products. Working with the US Environment Protection Agency (EPA), the Texas scientists reported they also detected low-level residues of several human medications.
Medicines in the water
While the study found the residue of several pharmaceutical and personal care products in fish tissue, it also demonstrated for the first time that fish from several locations across the country are exposed to multiple pharmaceutical and personal care products (PPCPs) in effluent-dominated waterways, according to Dr. Bryan Brooks, associate professor at Baylor University.
The US Environmental Agency (EPA) made a pledge in August 2008 to further investigate the effects PPCPs have on the nation’s waterways. The EPA-sponsored scientists tested for 36 different compounds in fish samples sourced at effluent-dominated waterways – 24 originating form medicines and 12 originating from personal care products. Of this total, the scientists found the residues of two compounds from personal care products and seven compounds commonly found in pharmaceutical products.
The two personal care compounds were galaxolide and tonalide, both fragrances that are used in a wide variety of soaps and other personal care products.
Feminized Male Fish
Although the scientists say the impact of all these compounds on the fish is not fully understood, the researchers stress there is documented evidence to suggest the contaminants lead to changes in behavioral patterns that influence fish survival.
Dr. Norris reported at the recent Endocrine Society meeting 18 out of the 19 wastewater samples that were examined contained trace levels of Bisphenol A. It is used in plastic baby bottles; food and beverage can linings and other products. The Centers for Disease Control estimated in 2004 that 95 percent of Americans have the chemical in their urine. A 2007 report from the US National Toxicology Program and the National Institutes of Health concluded Bisphenol A presents “some concern” about exposure of fetuses and children at current human exposure.
Future Generations May Be Affected
Are EDCs contributing to the early sexual development of girls?
Are EDCs leading to feminization of boys?
Dr. Norris warned at the recent Endocrine Society meeting: “The fish are a wake-up call. Our bodies and those of the much more sensitive human fetus are being exposed everyday to a variety of chemicals that are capable of altering not only our development and physiology but that of future generations as well.”
Resources: Chemicals Remaining after Wastewater Treatment Change the Gender of Fish
Released: 6/21/2010 12:15 PM EDT
Source: Endocrine Society
Arizona Department of Environmental Quality http://www.azdeq.gov/environ/water/wastewater/pharm.html
JA. Katzenellenbogen , Environmental health Health Perspect. 103 Suppl 7:99-101(1995)