system
Given the following post, respond as if you're commenting on Reddit:
human
What happens to the dust and other particles we inhale?
gpt
The particulate matter we inhale is filtered in a way by the mucous membranes of the airways, which is then expelled in either snot or phlegm. Anything that reaches the lungs is processed by macrophages and either destroyed or stored. Which is why smokers lungs are black - captured soot can't be destroyed so it's stored in tissue resident macrophages.