Scientists at Columbia University have reported that when water molecules meet the surface of microplastic particles, they trigger a chemical reaction that creates reactive oxygen species (ROS), a class of free radicals capable of harming cells. The findings, published in the journal Nature, showed that exposure of mouse red blood cells to these ROS‑producing plastics led to cellular deformation and rupture, providing a potential explanation for how microplastics could affect human health.
Chemical Reaction Between Water and Plastics
In the initial phase of the study, researchers introduced water to microscopic fragments of six widely used polymers: polyethylene, polypropylene, polystyrene, polyvinyl chloride (PVC), poly(methyl methacrylate) (PMMA) and polyethylene terephthalate (PET). Measurements indicated that the interaction generated varying amounts of ROS, with polyethylene and polypropylene producing the highest levels, while PMMA generated comparatively fewer radicals.
Cellular Impact Observed in Mouse Red Blood Cells
Subsequent experiments involved exposing mouse red blood cells to each type of plastic. The cells displayed altered morphology and eventually burst, and the degree of damage correlated with the amount of ROS each plastic type generated. The researchers noted that the more ROS a plastic surface produced, the greater the observable cellular injury.
The team emphasized that the experiments were conducted in vitro and do not prove that the same reactions occur in the human body. However, they highlighted that as plastics fragment into ever‑smaller particles, their total surface area expands dramatically, potentially amplifying ROS formation wherever water is present—including within human cells.
Implications and Future Directions
Earlier work by the same Columbia group in 2024 revealed that commercially available bottled water contains microplastic concentrations ten to one hundred times higher than earlier estimates, with ninety percent of those particles classified as nanoplastics small enough to cross the blood‑brain barrier and enter cells. Environmental chemist Beizhan Yan, a co‑author, described everyday activities such as laundry and microwave reheating as sources of billions of these nanoparticles.
External experts cautioned against drawing premature health conclusions. University of New Mexico professor Matthew Campen noted that adding the surfactant Triton X100 eliminated ROS production in the lab, suggesting that other compounds present in the body might mitigate free‑radical generation. Nonetheless, the study is regarded as a foundational look at how the most abundant chemical on Earth—water—interacts with plastic surfaces to produce potentially harmful hydroxyl radicals.
The research arrives amid growing governmental attention to plastic pollution. In April, U.S. officials announced a $144 million program to investigate microplastic presence in human tissues and drinking water. Public health advocates, including Stanford epidemiologist Tracey Woodruff, urged individuals to reduce plastic exposure now, warning that delayed action could exacerbate health risks.
Mitchell Landsberg is a Senior Technology Correspondent at News Raise. He covers consumer electronics, artificial intelligence, software developments, and digital privacy trends.
