Attorney General Bonta Sends Comment Letter to EPA on Microplastics

OAKLAND - California Attorney General Rob Bonta today joined a multistate coalition of 14 attorneys general in sending a comment letter to the U.S. Environmental Protection Agency (EPA) commending EPA's efforts to add microplastics to a list of contaminants in drinking water prioritized for research, and urging EPA to further monitor microplastics.

"Microplastics are everywhere, from the deepest ocean to the highest mountain, and even in our bodies, causing damage - in ways known and unknown - to our environment and potentially our health," said Attorney General Bonta. "We commend EPA's efforts to add microplastics to the list of contaminants in drinking water that are prioritized for research. This is an important step for protecting our environment and public health, but we can and should go further. More data can only make our work to protect the public from microplastics more effective."

The list, called the Contaminant Candidate List (CCL), details contaminants that the EPA has identified as those with potential public health concerns that are known or expected in public water systems, and thus may require future regulation under the Safe Drinking Water Act. The CCL, which is published every five years, is a mechanism for identifying priority contaminants for further study. The inclusion of microplastics in this iteration of the CCL will help advance our understanding of the impacts of microplastics on public health.

In the letter, the attorneys general urge the EPA to go one step further and include microplastics on the upcoming Unregulated Contaminant Monitoring Rule (UCMR) 6. The UCMR requires monitoring of selected contaminants in public water systems for frequency and occurrence. As the letter argues, inclusion of microplastics in the UCMR will advance research on microplastics in drinking water and lay the groundwork for their future regulation.

The Danger of 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 tiny, often invisible particles less than 5 millimeters in diameter - even as tiny as one nanometer - composed of polymers and various chemical additives that were either originally part of a plastic product or were adsorbed from the surrounding environment. They pose significant risks to human and environmental health due to their abundance in our planet's water, air, and land.

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 may 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.

As the comment letter notes, 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.

Microplastics are linked to reduced birth weight, prematurity, deficits in brain development, respiratory issues, allergy, metabolic effects, reproductive system alterations, and systemic effects such as inflammation, oxidative stress, and multi-organ toxicity.

In filing the comment letter, Attorney General Bonta joins the attorneys general of New Jersey, Connecticut, Delaware, Illinois, Maryland, Massachusetts, Michigan, New York, North Carolina, Oregon, Vermont, Virginia, and Wisconsin.

Here is a copy of the letter.