President Donald Trump’s administration announced Thursday it wants to fund research on microplastics and pharmaceuticals in public drinking water and examine their potential health impacts. The proposal could help environmental regulators create future drinking water restrictions.

The federal government also announced a $144 million program to measure, research and remove microplastics from the human body as part of the administration’s Make America Healthy Again initiative. The program will prioritize pregnant people, children, patients with chronic conditions and workers in high-exposure environments.

“We will give the American people clear answers about what’s in their bodies and what it means for their health,” said U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr.

How do microplastics enter our bodies?

Microplastics are tiny particles derived from plastic waste that break down into small pieces, contaminating soil, air, food and water. Once ingested, microplastics can bioaccumulate in the body.

Pharmaceuticals, from antidepressants to pain relievers, are known to enter water systems through human waste and improper disposal. A 2008 Associated Press investigation found pharmaceuticals in the drinking water supplies of at least 41 million Americans. The Philadelphia Water Department had some of the highest levels.

Every five years, the  Safe Drinking Water Act  requires the Environmental Protection Agency to publish a list of unregulated contaminants to help prioritize research and funding. The list supports the agency in making decisions about potential drinking water regulations. The EPA’s draft Sixth Contaminant Candidate List features both microplastics and pharmaceuticals.

The list also identifies toxic PFAS, or “forever chemicals” because they don’t break down naturally, and disinfection byproducts, as well as  75 chemicals and nine microbes that may appear in drinking water.

“This is a direct response to the concern of millions of Americans who have long demanded answers about what they and their families are drinking every day,” said EPA Administrator Lee Zeldin in a statement. “This will allow us to better understand the potential risks of these substances in drinking water while advancing gold standard science.”

In recent years, growing concerns about the health impacts of microplastics have spurred greater research urgency. Some researchers say exposure to microplastics could increase heart attack or stroke risks.

However, people are more likely to be exposed to microplastics from plastic bottles and food containers, said Samantha McBride, an assistant professor at the University of Pennsylvania who has researched microplastics.

“We have done some experiments ourselves in the lab, where we compare the microplastic in plastic bottled water, also within aluminum cans, which have a plastic liner,” she said. “The amount of microplastics in tap water is absolutely minimal compared to those other sources.”

There has been far more research on the scope of pharmaceuticals in surface water and drinking water, said Heather Preisendanz, a professor of agricultural and biological engineering at Penn State University. While commonly detected in waterways and tap water, levels of pharmaceuticals remain well below prescribed doses.

“If you are near a potential source like wastewater treatment plants that don’t fully remove pharmaceuticals in the influent water, then they’re going to be discharged into the receiving stream,” Preisendanz said. “We often see them transported through groundwater pathways, as well to surface water bodies, because they’re not fully treated in septic tank systems.”

The EPA also announced Thursday that it is releasing so-called “human health benchmarks” for 374 pharmaceuticals. Though unenforceable, the benchmarks could help local water systems evaluate risks and protect their communities if contaminants reach concerning levels.

The general public is encouraged to submit comments on the proposed list for 60 days.

Read more from our partners, WHYY.