These all link to quite old studies and as I mentioned there’s far more than one link in the slate article I linked showing that the risks of secondhand smoke have not been substantiated by more modern research in the last 10 years. Certainly nowhere near the certainty with which you casually throw around the “50,000” number as though it is heaven’s writ.
Let’s also be clear, even if that number was correct it in no way justifies banning cigarettes or tobacco smoking. Secondhand smoke is a public health issue in public, which laws and regulations have largely removed it from public settings. If people are exposed to secondhand smoke in private settings it is not the issue of government to intervene.