Governments all over the world have enacted laws to try to limit the number of smokers. Not only smokers are at risk, but also those who live near smokers and thus are exposed to the harmful effects of passive smoking or smoke exposure.
Children, who of course have no choice about exposure to tobacco suffer more cases of asthma, and even have a higher lifetime risk of certain cancers when living with smokers.
A law was recently passed in Scotland which makes it illegal to smoke in cars with children. This may seem draconian to some, but when you think about it, smoke in cars is much more concentrated than in other areas as there is just not a lot of space in cars. Sure, you can open the windows but the smoke still manages to hang out all over the car.
i have heard from many parents that yes, we smoke but we only do it outside. What about in your cars? Just as you can smell tobacco on a smoker hours after the last cigarette, so too the cancer causing substances can be inhaled by others including children hours later as well.
Bottom line: If you are a smoker and have kids do yourself and your children a big favor: Stop smoking! You will be much more likely to live to see them get married and less likely to be on oxygen during their weddings. And your kids are less likely to have asthma or lung cancer. If your kids see that you stopped smoking then they are less likely to take it up themselves.