Inhaling burnt organic matter is associated with higher lung cancer risk:
https://news.mit.edu/2021/pah-cancer-chemicals-0922
And inhaling fine particulates increases the occurrence and severity of respiratory diseases:
You’ll probably be shocked to hear that people who smoke cannabis are less likely to develop lung cancer than those who don’t smoke.
“We hypothesized that there would be a positive association between marijuana use and lung cancer,” the study’s lead author explained. “What we found instead was no association at all, and even a suggestion of some protective effect.”