Originally Posted by BimmerHJ
Small rust particles can be a serious safety issue, and over the years of rust procedures, you may breath in tiny rust particles in your lung and can cause cancer.
Nonsense, other than possibly with heavy occupational exposure - continually introducing any small particles into the lungs can cause health issues, hardly an analogous situation.
There happens to be recent research however that nano sized bits of iron oxide can be employed to fight cancer. It's a bit more complicated than breathing it in however.