“Forever chemicals” associated with severe health risks can be found in almost half of all U.S. tap water, and 70% of urban tap water sources, a first-of-its-kind federal survey released Wednesday found.

Per- and polyfluoroalkyl substances, or PFAS, refer to a group of more than 12,000 chemicals that are widely used in everything from consumer products to fracking.

Researchers with the U.S. Geological Survey tested for 32 of the most common types of PFAS from home, school, and commercial taps across the country between 2016 and 2021, including near protected lands and residential areas with no known PFAS sources or proximity to identifiable risk factors.

The survey found no measurable difference in PFAS concentrations between public and private water sources, but substantial variation between urban and rural water sources.

Previous research has illustrated the link between higher PFAS exposure in Black and Latinx communities and the intentionally discriminatory citing of sources of pollution such as chemical waste sites, airports, factories, and other industrial facilities near communities of color. PFAS are linked to significant adverse health effects, such as higher risks for cancer and developmental delays in children.

In March, the U.S. Environmental Protection Agency proposed the first ever PFAS standard for drinking water, and a final rule is expected around the end of the year.

(Washington PostGizmodoAxiosThe Hill)