EPA, HHS look to STOMP out microplastics contamination

from the U.S. Environmental Protection Agency and U.S. Department of Health and Human Services

U.S. Environmental Protection Agency Administrator Lee Zeldin and U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. on April 2 announced landmark, coordinated actions to address microplastics contamination, one of the most urgent and growing public health challenges facing Americans.

The announcements, made at a press conference at EPA headquarters, represent a major step forward in President Trump’s commitment to Make America Healthy Again.

For the first time in the program’s history, EPA is including microplastics as a priority contaminant group in its draft Sixth Contaminant Candidate List, CCL 6, now open for public comment.

CCL 6 also includes pharmaceuticals as a group—another first—along with per- and polyfluoroalkyl substances (PFAS), disinfection byproducts, 75 individual chemicals, and nine microbes that may be present in public drinking water systems.

The CCL is a critical tool under the Safe Drinking Water Act (SDWA) that drives research, funding, and future decisions on regulating emerging threats to drinking water. By elevating microplastics and pharmaceuticals to priority group status, EPA is directly responding to the concerns of millions of Americans who have long demanded greater transparency and accountability about what is in their water.

Additionally, the Advanced Research Projects Agency for Health (ARPA-H) announced the launch of STOMP—Systematic Targeting of Microplastics—a first-of-its-kind nationwide initiative to build a comprehensive toolbox for measuring, researching, and removing microplastics and nanoplastics (MNPs) from the human body.

STOMP takes a three-pronged approach:

• Measure: Deploy gold-standard detection technology to accurately quantify microplastics levels in water and human tissue.
• Target: Identify the most harmful plastic contaminants and determine how they enter and move through the body.
• Remove: Develop and validate methods to eliminate microplastics from the human body.

“Microplastics are in every organ we look at—in ourselves and in our children. But we don’t know which ones are harmful or how to remove them,” said Alicia Jackson, Ph.D., ARPA-H Director. “Nobody wants unknown particles accumulating in their body. The field is working in the dark. STOMP is turning on the lights.”

The STOMP program, led by Program Managers Drs. Ileana Hancu and Shannon Greene, is designing its tools to be fast, affordable, and broadly available because the goal is not a breakthrough that reaches the few, but a foundation that protects everyone and helps to lower the potential downstream costs that microplastic-related disease could otherwise impose on our healthcare system.

STOMP will focus on three technical areas across two phases: measurement and mechanism (phase one) and removal (phase two).

“A key first step is to measure microplastics accurately and understand how they reach different organ systems,” said ARPA-H Program Manager Ileana Hancu, Ph.D. “So we must establish a solid, shared foundation for precise measurement and mapping.”

During the first phase, STOMP performers will design experiments to understand microplastics within the human body. They will also develop gold-standard microplastics measurement methods, including a clinical test that will quantify individual microplastic burden, thus making monitoring and intervention possible at scale. While microplastics accumulation in the human body is a generally shared concern, the extent of accumulation is not agreed upon. This happens mainly because measurement techniques are not good enough, producing inconsistent results across labs. The CDC will serve as an independent validator of these methods, ensuring the field can trust what it’s measuring.

Critically, this work will then produce a risk stratification mechanism for plastic materials—ranking them by biological harm—so that scientists, policymakers, and industry share a common answer to the most important question in the field: which microplastics need to be addressed first, most urgently, and in what ways.

ARPA-H Program Manager Shannon Greene, Ph.D. noted, “It’s physically impossible for us to completely divorce our lives from plastics. They are in everything we touch—our clothes, the materials from which we get our food and water. We need to understand how microplastics are distributed throughout the body and what harm they are causing before we can take the next leap forward to ultimately remove them and improve human health.”

Removal is the focus in phase two and where the earlier work proves indispensable. Different microplastics accumulate in different organs, cross different cellular barriers, and disrupt different biological pathways. Only by knowing which types cause the most harm, where they concentrate, and how they move through the body can we design interventions that are precise, safe, and effective. The approaches will draw on pharmaceutical biology and bioremediation science, run in reverse.

These technologies will enable individuals and healthcare providers to detect and reduce potentially harmful microplastics, particularly for vulnerable groups such as pregnant women, children, patients with chronic disease, and highly exposed workers. With reliable, broadly available testing methods, public health authorities, regulators, and health stakeholders could guide policy, monitor interventions, and address health impacts for decades to come.

ARPA-H expects that teams will be needed to address the full goals of STOMP. Prospective proposers are encouraged to form multidisciplinary teams with a range of technical expertise. Learn more about STOMP on its program page, including details about the solicitation and Proposers’ Day registration.

Together, these two initiatives represent the most comprehensive federal effort to date to understand and combat the risks posed by microplastics to public health.

The announcements were unveiled at EPA headquarters in Washington, D.C., where Administrator Zeldin and Secretary Kennedy were joined by senior agency officials for a press conference before the public.

“For too long, Americans have vocalized concerns about plastics and pharmaceuticals in their drinking water. That ends today,”
said EPA Administrator Lee Zeldin. “By placing microplastics and pharmaceuticals on the contaminant candidate list, for the first time ever, EPA is sending a clear message. We will follow the science, we will pursue answers, and we will hold ourselves to the highest standards to protect the health of every American family.”

“Today, HHS and EPA are taking decisive action to confront microplastics as a growing threat to human health,” said HHS Secretary Robert F. Kennedy Jr. Americans deserve clear answers about how microplastics in their bodies affect their health.

“Through ARPA-H’S STOMP program, we will measure microplastic exposure, identifying sources of risk, and develop targeted solutions to reduce it.”

The press conference was followed by an expert panel discussion examining the scope of microplastics and pharmaceutical contamination in America’s drinking water and the real-world impact of today’s actions.

Panelists included:

• EPA Assistant Administrator for the Office of Water Jessica Kramer;
• ARPA-H Director Dr. Alicia Jackson;
• Leading microplastics researcher Dr. Marcus Eriksen;
• Scientist Matthew Campen, whose research has documented the presence of microplastics in human tissue;
• Leonardo Trasande, an internationally renowned leader in environmental health whose research focuses on identifying the role of environmental exposures in childhood obesity and cardiovascular risks;
• Colleen Flaherty, division director in EPA’s Office of Water where she leads initiatives to understand and reduce microplastic pollution in the nation’s waterways.