I don't know of anyone who isn't aware of the health hazards of smoking.
The one inescapable truth in all of this, though, is that whether you die from lung cancer, an obesity-derived heart attack, a car crash, a bungee jumping accident, or any of the other activities in life that are a risk to one's life and health... you're just as dead. So either we must accept that life, in general, is hazardous and that we're all free to choose our own risks for whatever perceived reward, or we must eliminate risk entirely by banning almost everything in life that makes it worth living.
Of course, that doesn't mean we have the freedom to intrude upon the rights of anyone else as we're pursuing our own risk/reward scenarios, but that's not what is going on or what's being advocated. Private businesses where you can smoke are not private businesses in which you must smoke as any sort of criteria. Those who smoke in these establishments are engaging in legal activities at a place in which the owner allows it. If the legal activities of others bother us, we can choose to do something else with no more drama than choosing to watch a different program on television or choosing not to go to a particular event or attraction. Concordantly, if a business that allows its patrons to smoke is not acceptable to us when seeking employment, we can choose to find a business that is smoke-free with no more drama than choosing to not work at an adult entertainment store if we don't like that sort of environment.
In the end, the only thing that should eliminate choices from our list of legal actions we can take are the consequences... and not the consequence of government regulation and enforcement, but the real consequences of death, poor health, financial ruin, personal or interpersonal hardship, and the like. If some choose to ignore one or more of those consequences, that is entirely their responsibility and entirely none of our concern.