Comment on Alternative medicine

• nymnympseudonym@piefed.social ⁨3⁩ ⁨weeks⁩ ago

  it’s trial and error all the way down

  Oh God LD50 is the craziest thing ever.

  Here’s how it works:

  Let’s just assume dose-response is linear. So, go find what concentration of chemical X (medicine, food additive, cosmetic, whatever) kills 50% of the bacteria/rodent/etc population. Draw a line from there down to 0% dead at 0 concentration.

  Now decide what % of deaths is acceptable, given the benefit of chemical X. Use the line we just drew and that tells you what the regulations should set for max concentration under as-directed usage.

  This ignores that - response curves are very often literally curves, sometimes with more than 1 minimum - response curves (and lines!) often depend heavily on all sorts of other chemicals’ presence in the environment, in varying mixtures & amounts

  It’s a combinatorial explosion we can never meaningfully test against. We do what we can, with the tools that we have.

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  • mirshafie@europe.pub ⁨3⁩ ⁨weeks⁩ ago

    Almost every signal response, and certainly in chemistry, is an S curve. A small span of that curve may be approximately linear, and you absolutely can not approximate it by just the mid point.

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