Early Puberty In Girls Caused by EDCs 

EDCs can mimic natural hormones, activating receptors that hormones do. As of recently, a large spike of early puberty in girls has been observed. A study done by the National Institute of Health tested if 10,000 different EDC compounds could activate the GnRHR or KISS1R receptors. These receptors are associated with hypothalamus (part of brain) sending a message to the anterior pituitary (part of pituitary gland) to start activating cells to initiate puberty. They found that many of these compounds have a connection with these receptors, one being musk amberette, a molecule used for fragrance in many soaps, detergents, and lotions. When testing on live zebrafish, they yielded a similar conclusion. Not much is known about what causes early puberty in general, so more studies are being conducted to find out more as this is a newer topic of scientific interest.   

https://www.nih.gov/news-events/nih-research-matters/certain-chemicals-may-trigger-early-puberty-girls