A recent study shows that exposure to microplastic pollution in fish leads to cellular changes, which impact the respiratory system and may disrupt endocrine systems.

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.”

“In addition to the fibers that fish eat, hundreds or thousands of microfibers also pass through their gills each day, and we find that this is where much of the damage occurs,” said Melissa Chernick, a researcher in Hinton’s lab at Duke’s Nicholas School of the Environment.

The team published its peer-reviewed findings March 9 in the open-access journal PLoS ONE.