Bisphenol A, or BPA, is found in many products intended for infants, including pacifiers.
Marcia Herman-Giddens first observed the age of puberty dropping for American girls in the late 1980s. Today, she and other researchers agree that the average age of onset has fallen significantly since the 1970s, and some point toward chemicals like bisphenol A—a ubiquitous hormone-like substance that the FDA recently refused to ban—as a possible cause. —ARK
The New York Times:
The medical wisdom, at that time, based on a landmark 1960 study of institutionalized British children, was that puberty began, on average, for girls at age 11. But that was not what Herman-Giddens was seeing. So she started collecting data, eventually leading a study with the American Academy of Pediatrics that sampled 17,000 girls, finding that among white girls, the average age of breast budding was 9.96. Among black girls, it was 8.87.
… One concern, among parents and researchers, is the effect of simultaneous exposures to many estrogen-mimics, including the compound BPA, which is ubiquitous. Ninety-three percent of Americans have traces of BPA in their bodies. BPA was first made in 1891 and used as a synthetic estrogen in the 1930s. In the 1950s commercial manufacturers started putting BPA in hard plastics. Since then BPA has been found in many common products, including dental sealants and cash-register receipts. More than a million pounds of the substance are released into the environment each year.