A team from the University of California, Santa Barbara, has published an article in PLOS ONE warning of how laundering clothes made from synthetic fibres may contribute to microplastics in water and increasingly, soil.

Our clothes made from synthetic fibres shed microfibres during the laundry cycle, and can be found “virtually anywhere in the environment,” authors of a new study published in PLOS ONE write.

Jenna Gavigan, Timnit Kefela, Ilan Macadam-Somer, Sangwon Suh and Roland Geyer say that while “emission pathways and quantities are poorly understood,” they have attempted to connect “regionalised global datasets on apparel production, use, and washing with emission and retention rates during washing, wastewater treatment, and sludge management.”

The University of California, Santa Barbara, team estimates that 5.6 million tonnes of synthetic microfibres were emitted from apparel washing between 1950 and 2016, with half of this amount emitted during the last decade.

According to the scientists’ research, “waterbodies received 2.9 million tonnes, while combined emissions to terrestrial environments (1.9 Mt) and landfill (0.6 Mt) were almost as large and are growing.

The amount of microfibres ending up at rivers and seas is just over half of all synthetic microfibres emitted from washing. An article in the BBC cites the researchers as equating this amount with “seven billion fleece jackets”.

Their research suggests that annual emissions to terrestrial environments and landfill combined are now exceeding those to waterbodies. The authors warn that the problem doesn’t go away by simply improving access to wastewater treatment, because while that may further shift synthetic microfibre emissions from waterbodies to terrestrial environments, the best solution to the problem would be “preventing emissions at the source.”

The dangers of plastics and microplastics in particular

Gavigan et al. point out that plastic pollution has “emerged as a key environmental issue” in recent years, with global production and use growing at a compound annual rate of 8.3 percent since the beginning of mass production around 1950.

They cite sources that assert that half of all plastics ever made by humankind were “produced in the last 13 years.” Plastics end up discarded in landfills, dumps or the natural environment, including rivers and seas and the soil.

The authors write: “Synthetic microfibres are considered a type of microplastic, which is typically defined by the longest dimension being less than 5mm. Microplastics have raised concerns due to their increased bioavailability, impacts on low-trophic organisms through the uptake of toxic chemicals, and increased risk of mortality due to ingestion.

Microfibres constitute a significant fraction of microplastics accumulating in freshwater, marine, coastal, terrestrial, and arctic ecosystems where they pose risks to aquatic organisms and terrestrial biodiversity. Humans are also impacted by the inhalation of airborne microfibres and consumption of microfibres found in common foods such as water, alcohol, seafood, sugar, and honey. Current literature suggests that microfibres may bioaccumulate in the lungs and trigger inflammation, however, the human health impacts are not well understood.”

Because people own more clothes and more people own washing machines,  microfibre emissions are on the rise (“growing quantities of synthetic microfibres into natural environments,” as the authors call it).

"I hear people say that the synthetic microfibre problem from apparel washing will take care of itself as wastewater treatment works become more widespread around the world and more efficient. But really what we're doing is just moving the problem from one environmental compartment to another," Roland Geyer, from UCSB's Bren School of Environmental Science and Management, tells BBC News.

“So then it becomes a terrestrial pollution issue,” Geyer points out to UC Santa Barbara’s The Current. “We just turned it into a different environmental pollution issue rather than having actually solved it.”

"Large-scale removal of microfibres from the environment is unlikely to be technically feasible or economically viable, so the focus needs to be on emission prevention," Bren School colleague and PLoS article lead author Jenna Gavigan says in the same BBC article.

The authors say more research is required into microplastic removal technologies, but that “recent literature suggests that synthetic microfibres can affect physical soil properties and microbial activity which may pose consequences for soil function and plant performance.” 

“There are huge unknowns,” industrial ecology professor Sangwon Suh tells The Current. “The amount of microplastics and microfibres that are generated is quite massive and continuing to rise, and if it continues there will be big changes, the consequences of which we are not yet sure. That’s what makes it concerning.”

Source: TRT World