After heavy exposure to cigarette smoke why does it linger in your nostrils for days?

Factual Questions
1

I’m a non-smoker. If I’m in a room for an exended period of time where there is heavy cigarette smoke or really thick incense, for days afterward I can sense a hint of the smoke smell in my upper nasal passages back where it connects to my throat. It’s subtle yet harsh at the same time, and it’s unmistakable that it’s the smoke I’m smelling.

Why does this happen? How can there be enough particles left in my nasal passages to sense this smell, or is it pulling the smell out of my lungs where combustion particles have settled and/or accumulated?

Why aren’t all the particles gone in few hours? Why can I smell what must only be a few molecules of this stuff, or does more airborne crap stick in your nostrils and lungs than you realize?

2

It’s coming out of your lungs - if you’re in a smokey area for a period of time yer gonna inhale the stuff and particles will settle in there. It can take a few days for them to totally clear out and that’s what your smelling.

As a non-smoker, you probably have a more sensitve sniffer and that’s why you’re detecting it.

3

Your entire breathing tract from nostrils to lungs is mucous membrane. All that mucous traps molecules of what you breathe. The smoke is trapped in your boogers.