I am wondering whether slight CO2 poisoning (hypercapnia) can be induced by everyday bad behaviour. I am particularly interested in the consequences of
The prolonged use of a surgical mask (a.k.a. procedure mask) typically when travelling.
Sleeping, the head underneath the blanket
I don't know how well oxygen and CO2 diffuse through a blanket / surgical mask and I don't know how quickly we pollute our own air through CO2 expiration.
Can these simple behaviours represent health trouble to "normal / healthy" adults?