Animal Impacts

To date, laboratory studies have largely looked at microplastics as a whole rather than specifically at microfibers. However, since microfibers are a primary constituent of microplastics, such research can provide useful insights.

Lab studies have found that microplastics can harm small aquatic organisms that eat them — including plankton, a hugely important food source for aquatic organisms. These harms include decreased ability to feed and reproduce. Zooplankton given food laced with microplastics in a lab had decreased nutrition and poorer health than the control group. And pearl oysters fed polystyrene microbeads had less energy.



There is concern about impacts due to chemicals that attach themselves to microfibers, too. Rochman fed fish microplastic pellets that had absorbed toxins via prolonged exposure to seawater near San Diego. The fish accumulated the chemicals — which included polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), all known carcinogens — and suffered liver toxicity and other pathological changes.

Advocacy groups such as 5 Gyres pointed to Rochman’s study, and to concern that microplastics, including microfibers, could cause large-scale harm by introducing toxins found in waterways (including the legacy industrial contaminants PCB and DDT) into the food chain, to successfully lobby for a U.S. ban on the sale of soaps and cosmetics with added plastic microbeads. (Canada and the United Kingdom have followed suit.)

plankton with microplastics

Humans consume microfibers via bottled and tap water, salt, beer, and seafood, according to a growing list of studies 

In a nutshell, we know very little about the impacts of microfibers on the health of nonhuman animals and people. But what we do know suggests a need for additional research.

Indeed, researchers are working to find out more about actual animal and human impacts. And at the same time, efforts are underway among advocacy groups, researchers and apparel brands aimed at everything from understanding how and which apparel sheds fibers, to preventing fibers from entering wastewater, to potentially altering how textiles are made to reduce shedding.