That doesnt mean anything. There is no evidence that shows that anything happens to you when from second hand smoke. Thats just how it is. Carbon monoxide from cars and cows butts, and a million other things are bad as well, hell, even carbon dioxide is bad in high doses, but there just isnt anything to support the THEORY that second hand smoke CAUSES or INCREASES serious bodily harm. There will be stories about the poor waitress that has cancer of the throat now. According to the non smoking orgs its cuz of all the people around her that smoked. How can this be proven? Would she have gotten cancer if she was a librarian? Was it the smoke that caused it, or was it the pancakes she ate for breakfast. Fact of the matter is, no major organization can prove that second hand smoke CAUSES ORRRR INCREASES the risk of cancer.
So, somone around you is doing something that makes you cough. That means you have the right to ban it because you are in discomfort? Fat people in tight clothes makes me vomit. Can we ban that too? What about fast food? It is a personal choice to decide to sit in a smokey area. Just like its a personal choice to eat the sugar/fat-filled nastiness they sell at burger king.
It is in a companies best interest to have non smoking and smoking sections due to business increase and catering to both sides. But for private use, as in bars, as in pubs, as in any other place where you CHOOSE to enter, it is YOUR decision to stay, and if you are uncomfortable, get the funk out.