 Studies indicate that girls who become sexually mature at earlier ages are also more likely to engage in risk-taking behaviors such as smoking, alcohol or drug use, and engage in unprotected sex.The current literature is inadequate to provide the information we need to assess the extent to which environmental chemicals contribute to precocious puberty.Gaps in our knowledge are the result of limitations in the designs of studies, small sample sizes, challenges to conducting exposure assessment and the few number of chemicals studied.