I'm confident that microfiber cloths are responsible for 0% (rounded to the nearest whole percentage) of oceanic microplastics. But it's possible that all clothing and fabrics combined are responsible for a significant fraction of microplastic pollution. If this is the case, then the government should do its duty in regulating externalities and mandate exhaust filters in washing machines.

Do you have a source on that? I'd like to understand the definition of "micofibre" in this context to see of I need to change my purchasing habits.

IDK about the claim, but here is a good dive into what it is and how it works. https://backreaction.blogspot.com/2013/05/what-is-microfiber...

The 85 % figure is from Environ. Sci. Technol. 2011, 45, 21, 9175–9179 https://pubs.acs.org/doi/abs/10.1021/es201811s

The 200-500 kiloton/year is from https://pubs.acs.org/doi/10.1021/acs.est.3c05955

For a deeper dive you can peruse the works that cite these articles, there's lots of research into microplastic population dynamics. Unfortunately most reach similar conclusions.

> The 85 % figure is from Environ. Sci. Technol. 2011, 45, 21, 9175–9179 https://pubs.acs.org/doi/abs/10.1021/es201811s

The abstract said a large proportion of microplastic fibers found in the marine environment may be derived from sewage as a consequence of washing of clothes. Not is derived. And not microfiber solely.

Microfibre materials (fabrics, etc) are by definition microplastics. They shed like crazy, too.