Columbia and UC Berkeley researchers find microplastics trigger chemical reactions

Researchers from Columbia University and the University of California, Berkeley, have discovered that microplastics are not chemically inert as previously assumed. A study published in the journal Nature reveals that when plastic fragments break down into microscopic particles, their increased surface-to-volume ratio allows them to interact with water to trigger spontaneous chemical reactions.

These interactions generate reactive oxygen species (ROS), which are high-energy free radicals. In laboratory experiments, these radicals were shown to cause biological damage; specifically, when mouse red blood cells were exposed to certain microplastics, the cells changed shape and ruptured. The degree of cellular damage correlated with the amount of ROS generated by the specific type of plastic.

Common plastics such as polyethylene and polypropylene were found to generate significant amounts of ROS, while others like PMMA (acrylic) produced less. Because human blood and cells are composed largely of water, scientists warn that these chemically active particles could potentially cause oxidative stress, inflammation, and DNA mutations within biological tissues.