What are human bioeffluents (in the context of air quality)?

February 2, 2023 2:54 AM

This Ask about CO2 and ventilation sent me down a bit of a rabbit hole and to papers with titles like “Effects from Exposures to Human Bioeffluents and Carbon Dioxide”. But no definitions! Obviously I am aware of the existence of bad breath, farts and BO: is that basically what they mean?

Are there other things I haven’t thought of? Or don’t know about? Are there any specific chemicals people think might be interesting?

I am purely asking out of curiosity. Google just kept sending me in circles.

posted by Bloxworth Snout to Science & Nature (5 answers total)

Best answer: I thought it might be talking about CO₂ produced by sewage but TIL that it seems to be rather a technical term for Volatile organic compounds (VOCs) like isoprene, monoterpenes and the short-chained carbonyls formaldehyde, acetaldehyde and acetone. Methane from farts is probably in the mix. Acetone [on the breath] can be a symptom of diabetes because, absent metabolizable glucose, the body tries burning fats with acetone as "an exhaust gas". There is increasing evidence that too much of any of these triggers physiological responses to minimize intake. Neat question, thanks.
posted by BobTheScientist at 3:59 AM on February 2, 2023 [2 favorites]

Best answer: Presumably it would also include things like Hydrogen Sulfide, methanethiol, dimethyl sulfide, and similar products of intestinal gas?
posted by Just this guy, y'know at 4:08 AM on February 2, 2023

Best answer: Human bioeffluents: Are exhaled and dermally-emitted bioeffluents different? appears to discuss the composition of bioeffluents. (I say "appears" because I haven't accessed the full paper.)
posted by Winnie the Proust at 7:29 AM on February 2, 2023

Best answer: According to my air quality monitor, in addition to carbon dioxide, humans breathe out (presumably a variety of) volatile organic compounds (VOCs).

They breathe out a lot more of them if they have recently been drinking alcohol, although I don't know how much of that comes from exhaled alcohol itself (ethanol is a VOC), how much comes from acetaldehyde (one of the main metabolites of ethanol in the human body, and also a VOC), and how much comes from other compounds.
posted by Juffo-Wup at 8:58 AM on February 2, 2023

Response by poster: OK, thanks everyone. I followed your links and clicked around a bit to follow links to similar papers and it seems to be mainly talking about compounds released from breath and skin. I can’t see any mention of intestinal gas, although you would imagine it does have an effect as well.

I still don’t really understand a lot of what I’m reading in terms of methodologies and so on, but I think I’ve got enough of an idea to satisfy my curiosity. And the take-away seems to be that ventilation is good, not just because of CO2 or pollen or manmade chemicals, but because our own bodies are working against us.
posted by Bloxworth Snout at 9:19 AM on February 2, 2023