American girls are hitting puberty earlier than ever, developing breasts at ages 7 or 8 instead of the traditional 10 or 11 years old, the New York Daily News reported on August 9.

　　Researchers at Cincinnati Children's Hospital Medical Center examined more than 1,200 girls aged from 6 to 8 and found that 15 percent showed signs of breast development at age 7. Compared to a similar study in 1997, American children’s puberty comes earlier significantly.

　　Researchers believed that girls with precocious puberty maybe caused by hormone secretion destroyed by some chemicals from living environment. However, the current suspect has not been confirmed.

　　据《纽约每日新闻》8月9日报道，最新调查发现，美国女孩出现性早熟趋势，青春期明显提前。很多女孩年仅7岁乳房就开始发育，而此前都是从10岁或11岁开始。

　　据报道，美国俄亥俄州辛辛那提儿童医院青少年医学研究部门，近日对1200多名6岁至8岁的女童进行了一项调查。结果显示，15%被调查者年仅7岁乳房就开始发育。与1997年一项类似研究结果相比，美国儿童的青春期发育大幅提早。

　　研究人员认为，女童性早熟可能由于饮食及生活环境中一些化学物质破坏了荷尔蒙分泌造成的，不过目前这一置疑还没有得到证实。