I know that the primary way that CO2 leaves a healthy human’s body from the blood is by diffusing into the lungs and then being exhaled. Is there any other way in which CO2 from the blood leaves the body? Since CO2 is a gas, it only leaves the body when gas is expelled. As far as I know, gas in only expelled during exhalation, burping, and farting. Is the CO2 released during burps and farts from the blood? Is there any other way that I didn't account for by which CO2 leaves the body?

[This link][1] states that an average person exhales about 500 liters of carbon dioxide every day. How do the numbers from burps and farts compare to that?

Here's why it might be useful: A doctor wants to measure rates of CO2 production in the body to very high accuracy by measuring average CO2 expulsion over a day by putting sensors on the patient's body, but if he didn't account for all the places in the body where CO2 is expelled, he'd underestimate the CO2 production rate.

Edit: Bicarbonate is a form of carbon dioxide, and it is excreted in urine.


  [1]: https://www.sciencefocus.com/planet-earth/how-much-does-human-breathing-contribute-to-climate-change/