Chronic exposure to microplastic fibers causes aneurysms, erosion of surface layers and other serious damage to fish gills, and increases egg production in female fish, a sign that chemicals in the fibers may be acting as endocrine disruptors, a new study by U.S. and Chinese scientists finds.

The minuscule fibers, which are made of polyester, polypropylene and other types of plastics, are shed or washed off of synthetic textiles used in clothing and other consumer and industrial products. Once shed, they enter wastewater and accumulate in oceans, rivers and lakes worldwide, accounting for more than 90% of microplastic pollution in some areas.

“Past field studies have shown that many fish eat large quantities of the fibers every day but have protective mechanisms within the gut that seem to be preventing damage,” said David E. Hinton, Nicholas Distinguished Professor of Environmental Quality at Duke University. “But when you extend your study down to the tissue and cellular levels, as we did, harmful changes are observed.”

Read more at Duke University

Image: These are Japanese medaka fish used in a new study that found microplastic fibers cause severe cell damage and possible hormonal changes. Fibers of polyester, polypropylene and other types of plastics are shed or washed off of synthetic textiles.  CREDIT: Duke University