More than 6 million Americans may be drinking water with unsafe levels of PFAs, a class of chemical linked to a number of health problems such as cancer, infertility, obesity, hormone imbalance and autoimmune disease. However, that number could be much higher.
According to a new study conducted by Harvard researchers, who analyzed 36,000 water samples, 75 percent of the contaminated water they found was detected in 13 states: Alabama, Arizona, California, Florida, Georgia, Illinois, Massachusetts, Minnesota, New Jersey, New York, North Carolina, Ohio and Pennsylvania.
The study doesn't identify specific areas contaminated, only sections of certain affected states. Those areas were near manufacturing sites, military sites, and wastewater treatment plants.
The scientists analyzed data from the Environmental Protection Agency in water samples collected between 2013-2015. But the EPA didn't have data on a full one-third of the country, roughly 100 million people, so those areas are unaccounted for.
That leaves researchers speculating that the number of water supplies with high levels of PFAs is much greater than they detected.
PFAs are chemicals that are resistant to heat, water and oil. They are used in products to protect fabrics, carpets and footwear from water and stains. They are used to insulate pipes and are in the chemicals used to fight fires.
PFAs are also used to prevent leaking or sticking in common household goods like pizza boxes, microwave popcorn bags, canned foods and teflon pans. Factory emissions sometimes contain PFAs.
"I think this study has important public health implications because drinking water affects so many people and we need to be careful about what chemicals we use and how we dispose of them in the environment," study author Xindi Hu told CBS News.
Currently the PFA levels in drinking water supplies are unregulated. However, this study could trigger the government to begin such regulation.
Right now, the EPA merely recommends levels they deem to be safe. In May, the EPA lowered the recommended safety levels of PFAs in the water than what they previously stated was acceptable.
On their website, the EPA describes PFAs as "persistent in the environment, bioaccumulative in wildlife and humans and are toxic to laboratory animals and wildlife, producing reproductive, developemntal and systemic effects in laboratory tests."