/stands on soapbox
People, and especially young people think nothing will happen to them from smoking. Granted when i was young I didn't think anything besides possible CF crap could happen to me either. My mom developed heart disease due to smoking, and since then has had several congestive heart failure bouts, and just recently went in for a carotid artery plaque removal procedure. Damn near everyone I know non CF (don't really know anyone else in person anymore with CF because they are all dead) wise smokes. I have really strong attachments with most of these people, going as far back as the age of 12 (i'm now 36). I like to have some beer on the weekends and be social. There are only maybe 2 or 3 bars (both are pretty lame) that don't smoke near me. Two of my favorite places to go and be social are smoking bars. Not to mention the place I REALLY like going to when they host tribute bands for some of my favorite artists (zeppelin, acdc, metallica, etc etc) is a smoking place also.
I so wish they would quit tip toeing around the issue and just flat out make ALL inside areas, regardless of business, a non smoking area by law, punishable by severe consequences if it's broken. I'm so sick of hearing "Dude, your in a BAR, what do you expect!?!?" from friends and others when I gripe about the smoke. No matter how I explain how I should be able to go to somewhere public and have a beer and a meal and fun with friends and not have to be subjected to assaults on my lungs, they just don't get it. I suppose they are just as biased as I am against smoke, but for their right to smoke. I guarantee you if when someone drank alcohol, the person nearest them got drunk, that would be regulated as well.
I'm all for peoples rights to mess them up, though I wish it wasn't something as pointless and unrewarding as cig smoke, but it should be a no brainer regarding cig smoke, which is some of the most toxic substance known to man. Exposing people who don't want to be exposed to that crap, there should be no question about it being unlawful. Thankfully, I go to the aforementioned places in small doses, and generally either go to smoke free bars when I want to drink, or stay home. But in the end, if a band I REALLY want to see is playing somewhere, I just accept it and realize i'd rather take some risks while I still can and enjoy something.
I'd like to figure out a way to equally upset smokers as I am upset with them assaulting my lungs in public. I've thought all kinds of things. Maybe carry around a personal media player with a large screen, and have really hardcore filthy scat porn on it, and as soon as they assault me with their smoke, I open my player and play the porn with full blast music and show it to them/his wife/kids/etc...Then when they freak out I could say "Well, I thought it was fair to ruin your night as much as you have ruined mine, and my health...Too bad hardcore scat porn doesn't give you brain tumors to make it really equal".
/ends soap box
As for your parents smoking in the house, I too was raised in this environment. I tried to stay away from them as much as possible, and our house reeked of smoke. My mom and dad finally quit, but im sure it did damage to me. One thing you must remember, people are selfish, and short sighted regarding their immediate needs. When those immediate needs are an addiction as strong as heroin or stronger, i'm sure you can see what they would choose. Also, i'm sure they don't think the second hand smoke really harms you. It took science forever to finally convince smokers that something they breathe in, then out, actually harms others to the extent it does. My advice, just try and make it to 18 and when you do, get a job somewhere, and get together with some friends and get a small apartment, one with a balcony where they can smoke. Because the chances of your parents figuring out what is up and respecting your health is pretty slim. About the only thing that could wake them up is you getting REALLY sick and them having a wakeup call. I would just personally stay as far away from them and your house as you can whenever you can. If you want to be vindictive (like me), and maybe help get your point across further, 100% isolate yourself from them in every way. No communication unless it's on the phone, and make it a point to show them if they won't respect your health, why should you respect their need to be around their daughter? That is what I would do until they got the point or I moved out.