I would like to see analysis of microplastics from water filters.
Water filters frequently use a very fine plastic mesh as their filter medium (eg. 'melt blown 5um polypropylene sediment filter'). I would expect that to give off a rather large number of particles the first time water is passed through it, and perhaps a good amount on an ongoing basis too since the mesh will flex with varying water flow.
Since people wanting to avoid pollution are likely to have water filters installed, it seems important to know how much pollution they are adding to the water they are trying to clean.
If microplastics are a huge problem (and they likely are), then tires are perhaps the largest source: Recent studies reveal that tire dust is actually responsible for 100x more pollution than the engine of an ICE car, and EVs (due to their increased weight and torque, which produces more tire dust particles) emit an additional 20% more tire dust than gas and diesel vehicles. Unintended consequences, and all that...
I think the author's mental model of what makes particulates dangerous is odd.
In part 1 of the post he mentions the molecular size of PFAs, and in part 2 he mentions benzene. I think "size" is not the relevant property - it's "does this molecule get imported into cells and alter some component of their activity". While molecular size is related to this, it's more about presence of transporters on the cells, hydrophobicity of the molecules, how the liver handles them (e.g. phase I/II metabolism) etc.
You can contrast this with asbestos, which is dangerous because it mechanically disrupts mucus clearance in the lungs without being imported into cells (also why asbestos + smoke is very dangerous, but asbestos alone probably not nearly as problematic).
Microplastics increase the surface area for degradation in the body, and thus might increase intestinal (and then blood) concentrations of plastic component chemicals or heavy metals they complex with. However, I think it's mainly a phenomenon of degradation in the intestine and then import into the blood stream. Contrast this with "microplastics get into the bloodstream intact". While there might be some of that going on (e.g. phagocytosis by macrophages, eosinophils, etc) I think it's the wrong mental model.
As a bit of reference, remember that your large intestine contains about 1E13 microbes/gram of digesta, and they are 0.2-2um in size. If the intestine let things of that size in at high rate we'd all have sepsis all the time
You are right - I am building a mental model along these lines:
a) compounds which induce a chemical reaction inside cells and as a result cause damage. Benzene, PFAS, phtalates, BPA etc are in this category. Size is less relevant but usually these are smaller and more reactive molecules.
b) small particulates, which are still probably much larger than those in group a). Thinking here microplastics, asbestos, PM10. These particulates are not necessarily super reactive with our cells, but they can cause problems through physical accumulation(?). So the question is: does the size of microplastic particles matter? Ie if I get 1K of 100 micron microplastic particles vs. 1K of 1 micron - does that alter my health risk?
Every time you dry your clothes and clean your lint trap you've just inhaled a million microscopic plastic particles. Unless your entire wardrobe is flannel, cotton, or linen.
> your entire wardrobe is flannel, cotton or linen
This is not that hard to accomplish and I've done it somewhat by default just by being a bit mindful about how my fabrics feel.
Still, I'm curious about your comment. I assume the airborne particles are from synthetic materials? Are any from soaps that go through the cycle, and if so, is liquid or powder a better option? It would be interesting to see data on microplastics in our laundry since most of what I see is focused on foods and water supply.
in the usa, most people do not dry by hanging clothes. I suppose that's what they're talking about. Not everyone is going to take the context as "the entire world" most people will think of their home country I think, I could be wrong.
I don't know how significant it is, but they found microplastics in the arctic, which is very far away from where it would have come from.
That makes it sound like you're going to come into contact with it no matter where you go. It's still a question of severity, but it suggests you aren't safe from it anywhere.
Water filters frequently use a very fine plastic mesh as their filter medium (eg. 'melt blown 5um polypropylene sediment filter'). I would expect that to give off a rather large number of particles the first time water is passed through it, and perhaps a good amount on an ongoing basis too since the mesh will flex with varying water flow.
Since people wanting to avoid pollution are likely to have water filters installed, it seems important to know how much pollution they are adding to the water they are trying to clean.