Well, as a Respiratory Therapist for longer than lots of you have been alive, I can assure you that second hand smoke is one of worst things possible. I have the largest bag over my head for smoking for 16 years. Back when I trained, everyone smoked. We used to joke about how it was like being a parent....do as I say, not as I do.
Rather than go somewhere such as straightdope.com to get medical information, perhaps looking at a place like the Mayo Clinic which is world renowned for it's medical care might give you a little insight on second hand smoke. Oh, and here's the link.
http://www.mayoclinic.com/health/sec...-smoke/CC00023
And no, I am not being arrogant etc etc etc. I can't tell you how many people I've had to comfort and try and ease their breathing while they were dying from the effects of cigarette smoke. I can't tell you how many hands I've held of people who were dying of second hand smoke. If only smokers REALLY knew what happens when you get COPD from smoking and breathing other's smoke....you have NO idea....it is among the most unpleasant ways to die. And yes, I've had people die on me in pretty much every way imaginable.
Your lungs do not heal themselves once you stop smoking. They regain SOME of their "pinkness" but not all. We have special cameras called bronchoscopes we use to look at people's lungs, and I can assure you that it's easy to tell the ones that have smoked....long after quitting. It's not just about the color.
Diesel trucks, SUV's etc...they are a problem, too, without a doubt. But nothing is as deliberate as taking that cigarette and lighting it. It's a brutal way to kill yourself. And for the poster that said that smokers shouldn't have to pay for health care because the don't live as long....you are wrong, my friend....Emphysema can torture you for years and years....wasting your body away slowly as you gasp for every breath....
Anyone that thinks that smoking should not be illegal is either ignorant or just not listening. The true facts are out there. Quit sticking your head in the sand.