tobacco is bad because of the fertilizer they're required to use to grow it that contains Lead-210 and Polonium-210.
when you smoke tobacco you're exposing yourself to ionizing alpha radiation. that's primarily why tobacco smoke is bad for you, aside from the other lung ailments that I'm not familiar with

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either way, you never hear of weed smokers with the same problems as cigg smokers, and there's a hell of a lot of pot smokers out there so maybe we should be seeing these drastic effects? somewhere? lmao.