I don't think there is ever going to be a right or wrong answer to this argument. Any time you are dealing with someone's rights, it is going to be debated from here to eternity.
Some salient points:
Okay - so you aren't comfortable going into a bar where people are smoking and you are a non-smoker. The 3-4 hours you spend in there isn't going to make that much of an impact on your health. First of all, unless you are sucking the exhaling smoke out of the other person's mouth, the nominal amount of smoke you breathe isn't enough to cause you lung cancer. The other argument is that it is for the benefit of the workers. WELL - here's where common sense comes in. If the fact that you work in a smoky environment bothers you - get another job. No one is forcing you to work there. My husband is a welder. He inhales fumes from welding rods, asbestos (yes, it is still in the schools on the boilers and walls) and, when he has to go under a building and crawl through a narrow space to weld pipes, he has no choice but to inhale the stuff. He's been doing this for 30 years - why? Because he enjoys welding - point being, he knew the risks going into the job. If he didn't like the risks, he would have gotten one that didn't put him in harm's way - much like a lot of other occupations out there.
Now, for the smoking/non-smoking part of a restaurant/bar. This is already in place in virtually every restaurant I have visited. The first question they ask after you tell them how many people in the party is "Smoking or Non." Again, the amount of smokers in a restaurant, versus the amount of non-smokers, greatly reduces the amount of cigarette smoke being projected into the establishment.
Every one wants to say that "I have rights, too" and you do. You have the right NOT to go into a particular restaurant/bar if the smoke is too much for you. The smokers have the right to sit their butt on a bar stool and smoke until the visibility goes down to zero. We could quote statistics all night long but the fact is - basically anything we do these days is bad for our health. You won't go into a bar where there is cigarette smoke but you'll eat fried chicken from Popeyes? Or, as Tim McGraw sang in his song, you'll have a ".99 heart attack" - referring to the fast food burger joints. All of these things are "supposed" to be bad for you but you still eat them. What were you planning to do when you went in that bar? Drink a beer? Well, there goes your liver. I'm sure you could probably find a statistic or one of those useless studies that "suggests" that drinking alcohol shortens your liver/kidney life expectancy.
I say, leave well enough alone, shut up and go about your life. After all, people who jogged 5 miles a day have dropped dead of heart attacks. When it's your time, you're outta here...
Cigarette smoke is the byproduct of a your pleasure. It contaminates the air, my hair, my clothes and my lungs. I also have a pleasure; I like beer. The byproduct of my pleasure is urine. How would you like it if I urinated on your head????
You miss the point dearest one. 
When I go home to Philly, I go to the bars in Delaware...they are smoke free. 
