Whether they know it or not, Americans are exposed to toxic chemicals on a daily basis: in their makeup, in frying pans, in pesticides and – most concerningly – in groundwater. 

The toxins are known as “forever chemicals,” referring to man-made compounds that do not naturally decompose in the environment. Formally known as perfluoroalkyl and polyfluoroalkyl substances – or PFAS – the compounds are frequently used to repel grease and water. 

Forever chemicals have long been associated with higher rates of cancer, reproductive and immune system harm and other diseases. But there have been no federal regulations on how to measure the amount of the chemicals in drinking water, despite the health risks, as there are for other inorganic chemicals like barium, fluoride, selenium and others. Several states have set their own drinking water limits to address PFAS contamination that are far tougher than the federal guidance. 

On Wednesday, the Biden administration warned the compounds may be more harmful than previously thought, and laid out a plan to address two specific forever chemicals found in U.S. drinking water.

The two compounds, known as PFOA and PFOS, have been voluntarily phased out by U.S. manufacturers, but there are a limited number of ongoing uses and the chemicals remain in the environment because they do not degrade over time. 

The Environmental Protection Agency warned the compounds found in drinking water pose health risks even at levels below the government’s ability to detect them.

The EPA also issued nonbinding health advisories that set the permissible health thresholds for PFOA and PFOS to near zero, replacing 2016 guidelines that had set them at 70 parts per trillion. The chemicals are found in products including cardboard packaging, carpets and firefighting foam.

At the same time, the agency is inviting states and territories to apply for $1 billion under the new bipartisan infrastructure law to address PFAS and other contaminants in drinking water. Money can be used for technical assistance, water quality testing, contractor training and installation of centralized treatment, officials said.

“People on the front-lines of PFAS contamination have suffered for far too long. That’s why EPA is taking aggressive action as part of a whole-of-government approach to prevent these chemicals from entering the environment and to help protect concerned families from this pervasive challenge,” EPA administrator Michael Regan wrote in a statement. “Thanks to President Biden’s Bipartisan Infrastructure Law, we are also investing $1 billion to reduce PFAS and other emerging contaminants in drinking water.”

The revised health guidelines are based on new science and consider lifetime exposure to the chemicals, the EPA said. Officials are no longer confident that PFAS levels allowed under the 2016 guidelines “do not have adverse health impacts,″ an EPA spokesman said.

While the new guidelines set acceptable risk below levels that can currently be measured, as a practical matter EPA recommends that utilities take action against the chemicals when they reach levels that can be measured — currently about four parts per trillion, a senior administration official told reporters Tuesday night.

The EPA said it expects to propose national drinking water regulations for PFOA and PFOS later this year, with a final rule expected in 2023.

In a related development, the EPA said that for the first time it is issuing final health advisories for two chemicals that are considered replacements for PFOA and PFOS. One group is known as GenX chemicals, while the other is known as PFBS. Health advisories for GenX chemicals were set at 10 parts per trillion, while PFBS was set at 2,000 parts per trillion.

The agency said the new advisories provide technical information that federal, state and local agencies can use to inform actions to address PFAS in drinking water, including water quality monitoring, use of filters and other technologies that reduce PFAS and strategies to reduce exposure to the substances.

Environmental and public health groups hailed the action as a good first step. Advocates have long urged action on PFAS after thousands of communities detected PFAS chemicals in their water.

Growing research shows the forever chemicals have increasingly leached into U.S. drinking water. According to the U.S. Geological Survey, a recent study of the Eastern United States found 60% of public-supply groundwater and around 20% of private well water sources contained at least one PFAS. Based on that data, the Environmental Working Group – a nonprofit focused on environmental issues – estimated over 200 million Americans drink water contaminated by PFAS. 

“It’s very troubling that PFAS were detected so frequently,” Scott Faber, EWG’s senior vice president for government affairs, said of the survey. “No one should have to worry about toxic forever chemicals in their tap water.”

The issue is particularly stark for marginalized communities, which have long borne the brunt of environmental hardship in the United States, for a host of reasons. Non-white Americans, in particular Black Americans, are more likely to live in areas of high pollution and with dangerous emissions, due in part to systemic racism and disproportionate investment in developments. 

Wednesday’s actions build on Biden’s PFAS Strategic Roadmap, released last year, that outlined how the administration planned to “develop a bold, strategic, whole-of-EPA strategy to protect public health and the environment from the impacts of PFAS,” with a particular focus on disadvantaged communities.