Today, American children are experiencing puberty at earlier ages than ever before. This phenomenon, which has particularly been on the rise over the past two decades, has been observed in both girls and boys.

In medical terms, early puberty is referred to as “precocious puberty” — the cut off is considered as before the age of 8 in girls and before the age of 9 in boys. Scientists are concerned that precocious puberty is becoming more and more prevalent, though the exact cause has not been identified yet. Could there be external factors that cause early puberty in pre-teen years? Read on to find out.

According to research, children who hit puberty early could be at risk of experiencing physical and psychological complications. For example, a girl who matures earlier than her peers may face social isolation or targeted harassment as a result. This can lead to emotional problems during a very vulnerable age.

“We know that the early-maturing girls are at an increased risk of some of these risk-taking behaviors: alcohol use, smoking, drug use, and earlier engagement in sexual behaviors,” Frank M. Biro of the Cincinnati Children’s Hospital Medical Center explained to the Scientific American in 2015.

However, parents do not have to panic — most children who experience early puberty do not face any serious complications as far as the evidence suggests. But scientists are still trying to examine the trend and understand if there is any controllable factor at play here.

Now, a new study published in the journal Human Reproduction suggests a possible link. Does the exposure to chemicals found in common household items and daily use beauty products play a role?

“We know that some of the things we put on our bodies are getting into our bodies, either because they pass through the skin or we breathe them in or we inadvertently ingest them,” said lead author Kim Harley, an associate professor at the University of California, Berkeley. “We need to know how these chemicals are affecting our health.”

The research team examined the concentrations of various chemicals in urine samples taken from the mother during her pregnancy and their children at the age of 9. While no associations were found with the boys, the same could not be said for their counterparts.

The findings revealed a link between early puberty in girls and high concentrations of diethyl phthalate, triclosan, and parabens in the urine samples. These chemicals are found in makeup, fragrances, soaps, detergents, aerosol sprays, and more.

“They can bind to hormone receptors, such as estrogen receptors, and influence changes in our bodies,” Harley told Inverse, noting how they have affected development in rats in animal studies.

However, more research is required as we still do not know if the chemicals themselves are causing the age of puberty to shift. The new study was limited due to variables like the mothers’ exposure to pesticides. But if parents are still concerned, you may try switching over to more organic or natural equivalents to these products whenever possible.