WASHINGTON >> For decades, American consumers have been buying water-resistant packaging and clothing, stain-resistant carpets and Teflon cookware. Now there is growing alarm that the chemical components that give those products their appeal are ending up in the water supply.

Drinking water in 33 states from New Jersey to California has been tainted by per- and polyfluoroalkyl substances, more commonly referred to as PFAS. Now they are also showing up in human blood: A 2015 study found PFAS in 97 percent of blood samples tested.

A newly released draft of a report by the Environmental Protection Agency says the substances that have made their way into drinking water are more dangerous to human health than previously thought. Its release was delayed for months after a Trump administration aide said it would create a “public relations nightmare.”

The substances are uncommonly difficult to break down. PFAS, of course, are water-resistant, but they are also used in firefighting foam and cookware for their ability to stand up against high temperatures.

Despite that resistance, microscopic particles break off and end up in the food chain, causing health problems from high cholesterol to cancer.

“It’s like the terrible comedian standing in front of a brick wall saying, ‘If Teflon doesn’t stick to anything, how do they get it to stick to the pan?’” said Mark Benvenuto, an industrial chemistry professor at the University of Detroit Mercy who has written about PFAS in a textbook. “Well, it didn’t. It would slide right off. They had to add things to it to make it less pure.”

Amid growing health concerns, policymakers in multiple states want to ban PFAS from food packaging and limit the substances in drinking water. New York is suing six companies that use PFAS in foams used to put out fires, hoping to recoup $39 million.

One study found the chemicals in one-third of fast-food packaging. Another found PFAS were at or above the EPA’s recommended level in water systems in 33 states, serving more than 16 million people.

The Environmental Working Group thinks the number of people affected could be closer to 110 million. The advocacy group has a map of sites it says are contaminated.

The sites are spread across the country, though some places have higher contamination levels than others. The water-systems study found areas close to military sites and airports where firefighting foam is used had more PFAS in their water.

Last year, DuPont paid $670 million to settle a lawsuit filed by 3,500 residents near Washington, West Virginia, home to a DuPont plant that made Teflon.

The company took female workers off the Teflon production line in 1981 after spotting birth defects in rats exposed to the products, but it wasn’t until 2005 that a medical study of 30,000 residents in the surrounding area was conducted.

In New Jersey, the Department of Environmental Protection last year pushed for a drinking water standard after PFAS showed up in 11 public water systems near a polymer plant close to the Delaware River.

Xindi Hu, a postdoctoral fellow at Harvard who coauthored the water-systems study, said scientists are still discovering how PFAS get into the environment. Scientists also are still examining how, and at what levels, PFAS affect humans.

So far, studies have found ties between PFAS and high cholesterol, cancer and weakened human immune systems.

Even as researchers continue to investigate, some policymakers argue the science is clear enough to take preventive measures.

Lawmakers this year in Washington state enacted a ban on some firefighting foams with PFAS. Another new law requires businesses such as fast-food restaurants and others selling packaged foods to stop using products with PFAS once the state settles on a suitable alternative.

A bill in California would require companies to disclose the presence of PFAS in packaging, and a bill in New York would ban them outright.

“People now realize it doesn’t just matter what you put in your mouth but what that food product is wrapped in,” said Washington state Rep. Joan McBride, the Democrat who sponsored the packaged-foods legislation. “These chemicals are called persistent chemicals. They stay with you, they’re insidious.”

In testimony on her bill, scientists warned of the dangers of PFAS while companies insisted they are safe. McBride said waiting for the state to determine a safer alternative gives companies time to work through stockpiles and even help develop a suitable replacement.

California Assemblyman Phil Ting, a Democrat, sponsored a bill to put a warning on products with PFAS “so consumers and restaurants can make that educated decision” about using them. “Because I’m not sure even restaurants understand the decision they are making.”

Manufacturers insist PFAS are safe.

“Fluorinated chemistries (PFAS) provide oil and grease repellent properties that help protect the quality and integrity of food, extend shelf life and help in the safe transport and storage of food. These attributes may help ensure our food is safer for consumption by protecting it from contamination,” the American Chemistry Council wrote in a statement to Stateline in response to an interview request. “Banning packaging containing PFAS is unnecessary.”

In New Jersey, efforts have focused squarely on water. The EPA recommends water contain no more than 70 parts per trillion of PFAS. New Jersey has suggested 13 and 14 parts per trillion for two different types of PFAS.

The guidelines are in the comment phase of rule-making. If approved, New Jersey would become the first state to set a maximum contamination level for PFAS. The goal of the new standard is to help utilities monitor sources and keep it out of drinking water.

Local water utilities have three main options to deal with PFAS: They can stop using certain wells that have high levels of PFAS, dilute the chemical by adding more water, or add a carbon-based treatment that removes the substance but can cost up to $1 million for large utilities to install.

“It can be treated, but it requires treatment that is above and beyond what a lot of these systems have in place,” said Lawrence Hajna, a spokesman for New Jersey’s Department of Environmental Protection. “Seeing this persistent chemical show up in water supplies is kind of opening up new questions of what kind of treatment systems can be put in place, what their effectiveness is going to be, and how costly is it going to be.”