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From the article: "analyzed the samples with laser direct infrared imaging and identified 20 to 500 micrometer-wide particles made from eight types of plastic,

From the article: "analyzed the samples with laser direct infrared imaging and identified 20 to 500 micrometer-wide particles made from eight types of plastic, including polyethylene terephthalate, polyvinyl chloride and poly(methyl methacrylate)." 500 micrometer is 0.5 millimeter. According to a random Quora user, that's about half the thickness of your credit card/a ziploc bag, a paper envelope, etc. Smal, but each sample "detected tens to thousands of individual microplastic pieces in most tissue samples", that adds up, though we don't know the distribution of sizes of those particules.

kazinator 3y ago
This is an American website, discussing metric quantities. Go easy on `em. The supposedly correct definition of a microplastic is anything from one micron to 1000 microns. That's three orders of magnitude, which is useless. A 1000 micron chunk has a million times more mass than a 1 micron chunk of the same shape and density.
- jjtheblunt 3y ago
  Did you square 1000 to get a million, in 3 dimensions? I'm not following the calculation. BTW Americans learned metric in school as kids (I did late 70s) and didn't learn the "Imperial" system, which I still don't know, but it seems that signs and so forth never got switched over. I have wondered for 40+ years if it's a laziness thing, and I don't know.
  - kazinator 3y ago
    Evidently I typo'd million where I wanted billion? Either that, or else I have a problem with metric of my own. If it was cubic mils in a cubic furlong, I'd never have made that typo. Metric makes you careless and lazy. :) So right, a one micron particle is a billion (10^9) times lighter than a millimeter (1000 micron) particle of the same density and shape. It's a big spread. The small particles will behave differently and get into different places from the large ones. The micron ones can pass through some membranes that the 1000 microns obviously cannot.
  - rngname22 3y ago
    I went to school in the mid to late 90s through the end of the 2000 aughts and we learned a bit of both Imperial and metric. It really depended on the context, a lot of American HS science classes used metric, a lot of times history or random math classes would make references to Imperial units, it's just a big grab bag tbh.
  - jjtheblunt 3y ago
    i found what predated me being taught metric (outside chicago), and it fits all 3 of our comments. https://en.wikipedia.org/wiki/Metric_Conversion_Act https://en.wikipedia.org/wiki/Metric_Conversion_Act

kazinator 3y ago

This is an American website, discussing metric quantities. Go easy on `em. The supposedly correct definition of a microplastic is anything from one micron to 1000 microns. That's three orders of magnitude, which is useless. A 1000 micron chunk has a million times more mass than a 1 micron chunk of the same shape and density.

jjtheblunt 3y ago
Did you square 1000 to get a million, in 3 dimensions? I'm not following the calculation. BTW Americans learned metric in school as kids (I did late 70s) and didn't learn the "Imperial" system, which I still don't know, but it seems that signs and so forth never got switched over. I have wondered for 40+ years if it's a laziness thing, and I don't know.
- kazinator 3y ago
  Evidently I typo'd million where I wanted billion? Either that, or else I have a problem with metric of my own. If it was cubic mils in a cubic furlong, I'd never have made that typo. Metric makes you careless and lazy. :) So right, a one micron particle is a billion (10^9) times lighter than a millimeter (1000 micron) particle of the same density and shape. It's a big spread. The small particles will behave differently and get into different places from the large ones. The micron ones can pass through some membranes that the 1000 microns obviously cannot.
- rngname22 3y ago
  I went to school in the mid to late 90s through the end of the 2000 aughts and we learned a bit of both Imperial and metric. It really depended on the context, a lot of American HS science classes used metric, a lot of times history or random math classes would make references to Imperial units, it's just a big grab bag tbh.
- jjtheblunt 3y ago
  i found what predated me being taught metric (outside chicago), and it fits all 3 of our comments. https://en.wikipedia.org/wiki/Metric_Conversion_Act https://en.wikipedia.org/wiki/Metric_Conversion_Act