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Effects of CO2 fraction on human health below clinical levels

Posted: Sun Apr 22, 2018 9:20 pm UTC
by Eebster the Great
Is there any evidence for subtle but measurable effects of elevated CO2 levels below those usually considered clinically significant? For instance, is it plausible that someone living most of his life in an atmosphere with 1000 ppm CO2 would suffer in any meaningful way in comparison to someone living at 300 ppm? I just mean in terms of direct effects on health, not indirect effects due to climate or whatever is responsible for putting out so much CO2.

Re: Affects of CO2 fraction on human health below clinical levels

Posted: Mon Apr 23, 2018 3:29 pm UTC
by p1t1o
According to the RTECS toxicology database (a prevalent database used in the chemicals industry) the "lowest published toxic concentration" in humans - (for the uninitiated, this doesnt mean "toxic" as in "Agh! Ack!" but "toxic" as in "we detected a toxic effect") is 0.25pph/0.25%/2500ppm.

This would suggest that toxic effects are not detectable below this limit.

The toxic effect detected at 0.25pph were categorised as "Lungs, Thorax, or Respiration - dyspnea Vascular - other changes", basically "shortness of breath".

Here's the ref. if you're interested:
VCVN1* "Vrednie chemichescie veshestva. Neorganicheskie soedinenia elementov I-IV groopp" (Hazardous substances. Inornanic substances containing I-IV group elements), Filov V.A., Chimia, 1988. Volume(issue)/page/year: -,328,1988

It is possible that lower concentrations could have an impact over the long-term, but exposing humans to toxic gases for long periods of time is not a study that would be easily approved, and therefore figures like this are often out of reach.

Re: Effects of CO2 fraction on human health below clinical levels

Posted: Tue Apr 24, 2018 3:33 am UTC
by Eebster the Great
Thanks, that's actually very helpful. I am having a discussion with a professor who is concerned about the distribution of CO2 emission rather than just the total emissions, in part because of effects on health. The fact that the smallest reported threshold for toxicity is five times what is commonly seen outdoors in cities (near the ground) certainly suggests his concerns are unfounded, at least in that respect.