Microplastics Newsletter: Q4 2025

Plant Uptake of Nanoplastics into Edible Tissues

Researchers at the University of Plymouth published a study demonstrating that nanoplastics can be absorbed by plant roots and transported into edible vegetable tissues. Hydroponically-grown radishes were exposed to polystyrene nanoplastics labeled with radioactive isotopes. The researchers observed particles moving into the roots, then translocating into the edible tissue and leaves. After five days, approximately 5% of the nanoplastics in the water were taken up by the roots. Of these particles, approximately 25% moved into the edible radish tissue, while approximately 10% were transported into the leaves.  The study demonstrated evidence that the particles moved beyond root surfaces into tissues not directly exposed to the nanoplastics, and therefore edible plants can be a source of nanoplastics exposure for animals and humans.

Heat Can Increase Microplastic Release in Everyday Beverages 

Researchers in the UK tested nine types of commonly consumed beverages, such as hot tea, hot coffee, iced drinks, soft drinks, juices, energy drinks, and water, and found microplastics in all samples. Hot drinks displayed the highest number of particles, with hot tea averaging approximately 60 microplastic particles per liter (MPs/L) and hot coffee approximately 43 MPs/L. Iced tea and iced coffee contained  between 31 to 37 MPs/L. Microplastics were also found in other beverages tested, such as packaged soft drinks, juices, and energy drinks with concentrations ranging between 10 to 30 MPs/L. Considering typical consumption rates, the study estimated that adults might ingest up to approximately 1.7 MPs per kilogram of body weight daily from these beverages. The findings indicated that factors such as temperature, cup materials, and packaging may influence microplastic release, and that everyday drinks, especially hot beverages, are a source of human exposure to microplastics.  

Potential Impacts of Microplastics on Lungs?

Researchers conducted a critical review of existing toxicological studies on the potential impacts of microplastics on human lungs. This study summarized eight mechanisms of toxicity that can result in lung damage, including oxidative stress, inflammation, apoptosis (cellular death), disruption of microbial balance, inhibition of lung surfactants, suppression of cell growth and division, pulmonary fibrosis, and effects of microplastics and co-pollutants. Inhaled microplastics can penetrate and impact lung tissue and is size-dependent, with smaller particles (≤80 nanometers [nm]) able to cross tissue barriers and distribute systemically, while larger particles (≥1 micrometer [μm]) can preferentially accumulate in lung tissue. Further research is needed to understand long term impacts of microplastics on lungs.

New Research Insights into Potential Links Between Microplastics Exposure and Cardiovascular Disease   

An experimental rodent study found that chronic exposure to polystyrene micro- and nanoplastics  (MPs/NPs) led to increased atherosclerotic lesions (a key process in cardiovascular disease), upregulated inflammatory cell and gene expression, and oxidative stress in male mice. The study demonstrated how exposure to MPs/NPs may contribute to the development and aggravation of cardiovascular disease, especially among males. Male and female low-density lipoprotein (LDL) receptor-deficient mice were fed a low-fat, low-cholesterol diet and given daily oral doses of MPs for nine weeks. Researchers found that MP exposure significantly increased atherosclerotic lesion size in male mice but not in females, suggesting a sex-specific vulnerability to the vascular effects of microplastics. While the exact reasons for reduced atherosclerotic risks in female mice are unclear, the researchers suggest there may be a combination of factors, such as sex hormones, sex chromosomes, genetics, and epigenetics, that could be contributing to the differences seen in the study. However, more research is required to provide a clearer understanding of mechanistic pathways and how this relates to human toxicity.  

Regulatory Roundup

U.S. Federal and State

• Microplastics regulation in the United States accelerated in 2025 as both federal and state governments introduced new measures to study and control microplastic pollution. At the federal level, two bills (H.R.4486 and H.R.4903) aim to evaluate human health impacts from microplastics in food and water and to expand coordinated research programs with dedicated funding. Several states are also moving forward with restrictions on products that generate microplastics and are adding microplastics to chemical regulatory frameworks. Because scientific data on health effects remains limited, many initiatives focus on research and monitoring. Additional regulatory action is expected in 2026 as new findings emerge. 

• CoPIRG has launched a campaign to reduce microplastic pollution in Colorado’s waterways, gathering thousands of signatures from residents urging stronger policies to prevent plastic waste, including spills of plastic pellets, packaging, and microfibers. Their efforts highlight both public concern and the need for upstream action, such as stricter regulation and waste reduction. The 2023 report Colorado’s Waterways and Microplastics found microplastics in all sixteen rivers and streams sampled along the Front Range, from remote mountain creeks to urban rivers, showing that microplastics are widespread and can travel downstream. The report reinforces CoPIRG’s call for action.

• To address the growing concern of microplastics in the Great Lakes, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) hosted their first Microplastics Awareness Week from October 19th through the 26th. The purpose was to encourage residents, businesses, and communities to learn about microplastics and how to reduce the amount of plastic used at home and work. Key activities during the week included cleanups, introduction to educational resources, and the Great Lakes Microplastics Summit, which brought together scientists, policymakers, and advocates to discuss how to detect microplastics and the risks microplastics present. Studies show microplastics enter the Great Lakes at approximately 10,000 metric tons annually, posing potential hazards to aquatic life and human health. EGLE is therefore investing $2 million over 2025 to 2029 to expand research and monitoring programs in order to develop a statewide strategy for microplastics prevention and policy.  

• Several Michigan environmental and public-health groups are urging Governor Gretchen Whitmer to sign a petition calling on the U.S. Environmental Protection Agency (EPA) to begin monitoring microplastics in the state’s drinking water, arguing that without federal testing, there is no standardized data on the extent of contamination. The petition is part of a broader effort to secure signatures from Michigan’s governor and governors from six other states (New Jersey, Delaware, Illinois, Maryland, Wisconsin, and Connecticut) and aims to prompt the EPA to include microplastics in its federal monitoring under the Safe Drinking Water Act, which would help collect consistent data across states. Advocates highlight that Michigan currently has no specific laws requiring testing in public water supplies, even though these particles have been found to be widespread. The groups hope the petition will be a first step toward federal regulation and greater protection of drinking water and public health. 

• Michigan lawmakers have proposed Senate Bill No. 503 to ban plastic microbeads by prohibiting the manufacture and sale of products that contain them. Senate Bill No. 505 has also been proposed and would require the state to study microplastics in waterways and drinking water and establish a long-term monitoring program.

International

• On 18 November 2025, England’s government passed a law to ban the sale and supply of wet wipes containing plastic. The ban is designed to reduce plastic pollution, curb microplastics entering waterways, and help prevent sewer blockage that may pose environmental hazards to rivers, lakes, and coastal environments. The legislation gives businesses until Spring 2027 to comply and transition to plastic-free alternatives.