But seems to be in line with NASA findings: https://thinkprogress.org/its-taking-less-co2-than-expected-to-cause-health-risks-in-astronauts-7af09e82b83 https:/

But seems to be in line with NASA findings: https://thinkprogress.org/its-taking-less-co2-than-expected-to-cause-health-risks-in-astronauts-7af09e82b83 https://thinkprogress.org/its-taking-less-co2-than-expected-... Also, the general safety limit for co2 is around 5000 ppm for up to 8 hours - higher than that, and headaches and other effects will manifest. I'm quite surprised that "no effect" could be seen at 40k ppm - I wonder if there were some limits to the cognitive tests (like the difference between proving a difficult mathematical theorem vs doing some Calculus).