My dad, a lifelong nonsmoker, taught high school math for 35 years and came home from work covered in chalk dust almost every day. About 17 years after he retired he was diagnosed with stage 3a adenocarcinoma. Happily after that everything has been positive so far - his treatment went well and he’s been cancer free now for over two years. It’s been almost four years since the diagnosis so I’m getting the idea it won’t come back though that’s still possible.
when I heard the diagnosis I internet surfed and found out about a Chinese university that experimented with chalk dust on rats. They found the same kind of inflammation in the rats’ lungs that makes people susceptible to lung cancer.