Researchers found chemicals from fracking that could cause infertility, cancer and birth defects in water near drilling sites in Colorado.
Scientists at the University of Missouri said the process of hydraulic fracturing uses 11 chemicals that can disrupt the body's hormones.
Researchers took surface and ground water samples from sites in Garfield County, which has more than 10,000 natural gas wells, according to the study.
Researchers say they found higher levels of hormone-disrupting chemicals in water near fracking sites than in areas without drilling.
"With fracking on the rise, populations may face greater health risks from increased endocrine-disrupting chemical exposure," said Susan Nagel, associate professor of obstetrics, gynecology and women's health at the University of Missouri's School of Medicine.
In the U.S. fracking "is exempt from federal regulations to protect water quality, but spills associated with natural gas drilling can contaminate surface, ground and drinking water," Nagel said.
The study is published in the Endocrine Society's journal Endocrinology.