Office of the
Illinois Attorney General
Kwame Raoul

Chicago — Attorney General Kwame Raoul, as part of a coalition of 14 attorneys general, affirmed the U.S. Environmental Protection Agency’s (EPA) efforts to add microplastics to a list of contaminants in drinking water prioritized for research and called for the EPA to further monitor microplastics.

Microplastics pose special concerns due to their suspected overall prevalence and their ability to accumulate and persist in the environment. They are generally described as often-invisible particles less than 5 millimeters in diameter, sometimes even as tiny as 1 nanometer, composed of polymers and various chemical additives that were either originally part of a plastic product or were adsorbed from the surrounding environment.

“Microplastics pose significant risks to human and environmental health and can be pervasive in our water, air and land,” Raoul said. “I am pleased that the EPA has proposed making this issue a priority for research, and I join my fellow attorneys general in calling on the agency to do more to monitor microplastics in public water systems.”

The EPA has proposed including microplastics in its Contaminant Candidate List (CCL), which is published every five years and identifies priority contaminants for further study. The list includes contaminants that the EPA has identified as posing potential public health concerns in public water systems and possibly requiring future regulation under the Safe Drinking Water Act. Including microplastics in the CCL will help advance understanding of the impacts of microplastics on public health.

In their comment letter, Raoul and the attorneys general urge the EPA to go a step further and include microplastics in the upcoming Unregulated Contaminant Monitoring Rule (UCMR) 6. The UCMR allows the EPA to monitor the presence of microplastics in public water systems by collecting data regarding their frequency and occurrence. In November 2025, governors from New Jersey, Delaware, Illinois, Maryland, Wisconsin, Michigan and Connecticut petitioned the EPA to request nationwide monitoring by adding microplastics to the UCMR. The EPA’s proposed UCMR 6 is currently under White House review and is expected to be finalized by the end of 2026.

Research conducted to date indicates microplastics can harm human health, and exposure occurs most often through drinking water and other beverages, breathing air and consuming food. Their size and shape can lead to cellular and tissue damage, and they have been found in all human organ systems, including the brain. In addition, microplastics can act as vectors for toxic chemicals to enter the human body, compounding exposure. Microplastics are linked to reduced birth weight, prematurity, deficits in brain development, respiratory issues, allergies, metabolic effects, reproductive system alterations, and systemic effects such as inflammation, oxidative stress and multi-organ toxicity.

Today’s comment letter notes that babies and children are at greater risk of exposure to microplastics than adults. This exposure begins in utero, since microplastics can transfer through the placenta. Microplastics have been found in placental tissue, amniotic fluid, cord blood and meconium, and are associated with impaired fetal growth and shortened gestational duration. Additional exposures occur after birth, such as through human breast milk, dairy products, drinking water and food products. Overall, children are exposed to microplastics through diet, feeding equipment, toys and inhalation of airborne particles.

 Joining Attorney General Raoul in submitting the comments are the attorneys general of California, Connecticut, Delaware, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Oregon, Vermont, Virginia and Wisconsin.