When you add it up, the total amount of synthetic microfibres going into the wider environment as we wash our clothes is an astonishing number.
US scientists estimate it to be 5.6 million tonnes since we first started wearing those polyester and nylon garments in a big way in the 1950s.
Just over half this mass – 2.9 million tonnes – has likely ended up in our rivers and seas.
That’s the equivalent of seven billion fleece jackets, the researchers say.
But while we fret about water pollution, and rightly so, increasingly this synthetic “fluff” issue is one that affects the land.
The University of California, Santa Barbara, team which did the calculations found that emission to the terrestrial environment has now overtaken that to water bodies – some 176,500 tonnes a year versus 167,000 tonnes.
The reason? Wastewater treatment works have become very good at catching the fibres lost from washing machines. What’s happening is those captured fibres, along with biosolid sludge, are then being applied to cropland or simply buried in landfills.
“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, told BBC News.