(NEW YORK) — Synthetic chemicals are being detected in America’s water supply at a rapid rate, potentially affecting millions of people over the past two decades, according to a data analysis by ABC News.

Researchers say that when people are exposed at high levels, these chemicals can increase certain health risks.

Per- and polyfluoroalkyl substances, also known as PFAS or forever chemicals, are a group of approximately 12,000 chemicals used to make a variety of industrial and consumer products such as nonstick pans, food packaging and firefighting foam.

Researchers are still studying the potential health impacts, but exposure at high levels have been linked to various health problems, including kidney and testicular cancer, high cholesterol and reduced response to vaccines, according to Jamie DeWitt, a professor of pharmacology and toxicology at East Carolina University.

The ABC News analysis of reported PFAS water contamination found that 43% of U.S. ZIP codes have had at least one water source where PFAS contamination was detected over the past 20 years.

The data, collected by ABC News from federal and state environmental agencies, show the number of new detections in water sources each year rose from 753 in 2013 to 2,321 in 2021.

That equates to at least 143 million Americans who have been possibly drinking, bathing and cleaning with contaminated tap water during that period. Additionally, millions more who may have been exposed to PFAS through contaminated water supplies at military installations, airports, manufacturing plants and other sources.

Researchers say that although most people in the U.S. have some level of PFAS in their blood, the health risks are greatest for those that have the highest exposure.

Last year, the National Academies of Sciences, Engineering and Medicine put out medical guidelines suggesting that people whose blood contains a high level of PFAS (more than 2 nanograms per milliliter) should get additional screening for high cholesterol, cancer and other potential health risks. People with lower levels of PFAS in their blood “are not expected to have adverse health effects,” according to the committee.

An ABC investigation found significant disparities in PFAS exposure in the U.S.

While PFAS contamination is widespread, contaminated water sites are more prevalent in ZIP codes that are poorer and more racially diverse than the national average, the analysis also found.

Of the ZIP codes where PFAS was detected in water sites, 49% were in ZIP codes where the median household income was below the 2020 national average of $67,521.

One in six ZIP codes with PFAS-contaminated water sites have a higher proportion of non-white population than the national average of 42.2%.

“(Contamination) is sprinkled in every single state in the country. It’s sprinkled in communities small, large, rural, urban, suburban. It’s all over the place,” Erik Olson, the senior strategic director for health at the Natural Resources Defense Council, told ABC News.

The 191-mile Cape Fear River, which runs through the region, is the most industrialized in the state — lined with manufacturing and agricultural plants. It is a drinking water source for more than 1.5 million residents in the region.

A North Carolina newspaper first reported in 2017 that a former DuPont chemical plant had dumped PFAS chemicals into the Cape Fear River for nearly 40 years.

DuPont owned the facility that polluted the river from 1968 until 2015, when it spun-off its PFAS business to a separate business, the Chemours Company.

Because Chemours was operating the facility at the time contamination was discovered in the river, the state of North Carolina investigated and fined the company $12M for violating clean water laws — part of a consent order the company agreed to in order to avoid further litigation.

DuPont officials would not respond to interview requests from ABC News. They were not charged with any wrongdoing because they had sold the company prior to 2017.

Although the Chemours Company declined to speak to ABC News for this story, they did provide an emailed statement saying, “We have and continue to implement state-of-the-art technologies, including a thermal oxidizer completed in December 2019 that destroys over 99.99% of PFAS air emissions.”

The company says it does additional work to treat the “legacy pollution” and reduce PFAS compounds from reaching the Cape Fear River.

Still, there’s an ongoing impact from PFAS contamination on residents in the region.

“North Carolina is kind of ground zero for unlocking and understanding where we are right now with PFAS contamination, especially with drinking water,” Emily Donovan, co-founder of Clean Cape Fear, told ABC News.

“It was kinda like a slow, rolling nightmare. Like a nightmare that you can’t wake up from,” Donovan said.

Blood tests performed between 2020 and 2021 on hundreds of residents in New Hanover and Brunswick counties in the Cape Fear region show almost all had levels of 44 different PFAS chemicals in their bodies.

The median blood level for PFAS chemicals in residents of New Hanover and Brunswick counties was 6 parts per trillion — far above the national average.

In nearby Cumberland County, Carolyn McDonald, a lifelong area resident, is convinced PFAS contamination has contributed to her health problems.

She used to love the taste of well water straight from the ground. But when she heard the groundwater was contaminated, she began to worry.

“I’ve been drinkin’ groundwater from the well all my life,” she said.

Now, McDonald, and her family, who live in the Fayetteville, North Caroline, area, buy bottled water twice a month.

June 5 will mark five years since she began kidney dialysis treatment. She wakes up at 3 a.m., three times a week, to travel about 30 miles to her dialysis center.

McDonald said she was shocked when she was diagnosed with kidney disease.

While impossible to prove PFAS was the cause of McDonald’s illness, research studies say that PFAS contamination increases the risk of kidney disease.

She says she also has nephews, a niece, brothers and friends who also lived in the area and drank the well water — who also suffer from kidney-related problems.

When she learned the contaminated groundwater could be a contributing factor for kidney disease, she says it all made sense.

“All these illnesses, all (of) us … drinkin’ the water. There’s gotta be a connection between the illness and the water,” she said.

The Environmental Protection Agency is responsible for monitoring PFAS contamination across the U.S. In October 2021, the EPA released its plan for addressing the problem, but by early 2023, it had only issued a few advisories and missed key deadlines.

This past March, the EPA proposed the first federal limits on six forever chemicals in drinking water. The proposal includes setting a limit of 4 parts per trillion, the lowest level that can be accurately measured, for two types of PFAS chemicals called PFOA and PFOS.

EPA Administrator Michael Regan said his strategy is to “hold corporate polluters accountable and work towards regulations that make it very clear what is safe and what is not safe.”

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