Thanks and noted, I'm happy to accept your figure. Even at 40% by number density that still means microplastics are hardly rare. I don't need to nitpick the exact number.

It was just an aside anyway. My main point is that MPs are vehicles for toxins, which addresses the original question about how (supposedly inert) microplastics can cause harm.

Thanks again for setting me straight, I must have misremembered.

It's good to keep in mind that there are a very broad range of figures. The Japan one was just the highest I could find with a quick search.

I like this study https://link.springer.com/article/10.1186/s12302-019-0279-9 not so much because they give a definitive answer, but the provide a much better sense of the nuance that bold claims miss. It's too easy to make a bold claim of a number that seemingly contradicts another similarly bold claim. The nuanced approach can often reveal that both bold claims are, in fact, true but not meaningful because they lose significant context.

For example, a lot of reports on water use neglect locality of the use. What the term 'use' means (how much water does a hydroelectric dam use, is that the same sense of use as irrigation?), is there scarcity where it is used? Is it the same class of water as the water in demand (potable / brine / etc.)

The haphazard use of terms has resulted in an insane range of claims of water use per AI query (or lithium mined, or tomatoes grown). The lack of faith leads people to assume one party is lying, but often all of the numbers are accurate in a kind of way. Just not comparable and sometimes not even meaningful