If there was a dump near my house that I believed contained hazardous material, I wouldn't go to that dump. I have no problem with anyone else who might want to visit that dump. If anti-smokers don't want to visit places where there is smoke, they are certainly free to go to places where there is no smoke. Or maybe just stay home, where there are no firearms either.
There are plenty of public health hazards all around us...McDonalds, AIDS, plastics. If this was about banning smoking for public health, the anti-smoking nazis would be whining about all the rest of the public health hazards as well. However, this is a FREE society, not a socialist society where we have to nose into everyone elses personal choices .