THURSDAY, April 8, 2010 (HealthDay News) -- Exposure to chemicals found in a wide range of consumer products may lead to delayed or early puberty in girls and increase their risk for health problems later in life, U.S. researchers say.
The three common classes of chemicals -- phenols, phthalates and phytoestrogens -- are known as endocrine disruptors because they interfere with the body's endocrine, or hormone, system. They're found in many consumer products such as nail polishes, cosmetics, perfumes, lotions and shampoos. Some are used in plastics or as coatings on medications or nutritional supplements to make them time-released.
The study included 1,151 girls, ages 6 to 8, who lived in New York City, Cincinnati and northern California. All three classes of chemicals were widely detectable in urine samples collected from the girls.
The study found that high levels of phthalates and phytoestrogens were strongly associated with early breast development. One phenol, two phytoestrogens and a subset of phthalates -- those used in building products and plastic tubing -- were associated with delayed puberty. But phthalates found in personal products such as lotions and shampoos were linked to earlier breast and pubic hair development.
"We believe that there are certain periods of vulnerability in the development of the mammary gland, and exposure to these chemicals may influence breast cancer risk in adulthood," Mary Wolff, a professor of preventive medicine and oncological sciences at Mount Sinai School of Medicine, said in a news release from the school. "Dietary habits may also have an impact. Further study is needed to determine how strong the link is."
The study was published online in Environmental Health Perspectives.
Previous studies have shown "that early pubertal development in girls can have adverse social and medical effects, including cancer and diabetes later in life," Wolff said.
"Our research shows a connection between chemicals that girls are exposed to on a daily basis and either delayed or early development," she said. "While more research is needed, these data are an important first step in continuing to evaluate the impact of these common environmental agents in putting girls at risk."
The U.S. National Institute of Child Health and Human Development has more about puberty.