Microplastics are pieces of plastic less than 5 millimeters long, too small to easily remove from the environment. They come from various sources, including microbeads from cosmetics, microfibers from synthetic clothing, tire fragments, and nurdles, tiny plastic pellets created to make larger plastic items. As microplastics do not degrade in nature, they persist in the environment, contaminate our food chains, and are now found almost everywhere on the planet.

Researchers have identified microplastics in over 90% of the world's water. The source of aquatic microplastic pollution can vary dramatically, from tire debris on roads, fiber sheddings in laundry, fragmentation of plastic litter, to runoff from industrial and agricultural sites. Once in our waterways, these contaminants move through rivers, groundwater, and treatment systems largely unfiltered, since most water infrastructure wasn't designed to deal with minute plastics.

Microplastics are known to accumulate in bodily tissues, including the brain, lungs, bloodstream, and reproductive organs. Once in our bodies, microplastics can potentially leach carcinogenic, neurotoxic, and endocrine-disrupting additives. A single bottle of water can contain up to 240,000 detectable plastic particles, about 90% of them nanoplastics (Qian et al., 2024), and humans ingest tens of thousands to over 100,000 microplastics every year from food and water combined (Cox et al., 2019). Water testing can show us exactly how much microplastic we're exposed to, and identify key sources of emissions so that the public, companies, and utilities can implement targeted treatment solutions.