What happens with dust when we breathe it in, where does it go?

Question

We breathe in dust all the time; dirt in the air, dead skin cells, smog, sawdust, etc. where does this all eventually go? It can’t physically all just build up or we would eventually suffocate right?

In: 48

Answer 1

The airways in your lungs are covered in a mucus layer. The walls are also lined with “cilia” which are like little hairs that are constantly “beating” in a direction that sweeps the mucus (and all the debris stuck in it) up and out of the lungs and into the throat, where you swallow it or spit it out. [Here’s a diagram of cilia](https://upload.wikimedia.org/wikipedia/commons/b/ba/Blausen_0766_RespiratoryEpithelium.png) for the sake of a visual.