# Microplastics Create Harmful Chemicals in Water > Microplastics in water generate damaging chemicals without needing external factors. - Title: Microplastics Create Harmful Chemicals in Water · Ars Technica - Summary: Microplastics in water generate damaging chemicals without needing external factors. Microplastics produce harmful chemicals in water through their… - Keywords: microplastics, water, chemicals, reactive oxygen species, polystyrene, polyethylene, polypropylene, pvc, pet, acrylic, hydroxyl radicals, oxidative stress - Source: Ars Technica — https://arstechnica.com/science/2026/10/microplastics-in-water-arent-inert-and-make-damaging-chemicals-on-their-own - Published: 2026-10-15T18:39:17+00:00 - Read time: 1 min - Topics: microplastics, water, chemicals, reactive oxygen species, polystyrene, polyethylene, polypropylene, pvc, pet, acrylic, hydroxyl radicals, oxidative stress ## Microplastics Are Not Inert Plastics were thought to be chemically inert but break down into microplastics found in drinking water, blood, and brains. > Whether microplastics can directly cause human disease is still being researched ## Microdroplet Chemistry Study Columbia University chemist Wei Min’s team found microplastics generate reactive oxygen species that damage DNA and proteins. > ROS will essentially bump into proteins, lipids, DNA, and cause damage ## Water-Plastic Interaction Water molecules at the interface with water-repellent plastics form unstable structures that generate hydroxyl radicals. > Their structure is no longer the regular water structure. They are perturbed, and their energy is also significantly increased ## Plastic Types Show Different Effects All six tested plastics generated radicals, with water-repellent plastics like polyethylene being most active. > The most water-repellent ones change the water structure the most ## Radical Production Mechanism Hydroxyl radicals form more easily at water-repellent surfaces due to reduced energy costs and negative electric charge. > hydroxide ions short on hydrogen bonds needed far less energy to form radicals ## Biological Impact Evidence Proteins and blood cells clump on plastic surfaces, with caffeine reducing clumping by neutralizing radicals. > Adding caffeine, which mops up radicals, largely stopped the clumping ## Animal Cell Damage Mouse red blood cells fragment when touching polystyrene particles, with damage levels matching radical production. > Mouse red blood cells that touched polystyrene particles broke into fragments ## Uncertainties in Real-World Exposure Microplastic exposure levels and aging effects vary, with older particles producing weaker signals. > Some microplastic particles were made 50 years ago, some were made five days ago ## Next Steps for Research Scientists aim to determine how much microplastic interface chemistry contributes to human disease. > We definitely want to see how much this effect is directly contributing to disease or biological problems ## Key takeaway Microplastics produce harmful chemicals in water through their interaction with water molecules, potentially causing cellular damage.