I am one of those dirty smokers, clogging the atmosphere with my cancer causing chemicals...
I dont smoke in front of patients, inside ambulance vehicles, while at the scene of an incident, and in places where I am not allowed (We have a funny piece of legislation called the Smoke Free Act 2003 that outlines certain areas where smokers are not allowed to be when they light up - most of society is covered in the ban). Believe it or not, the legislation is being expanded to cover private vehicles, homes and air spaces out the front of homes - much like the legislation in the UK.
For the sake of partners and patients, I do however remain discrete and always carry a can of deoderant with me for when I finish smoking, and try and wear other clothing over the top of my uniform (eg a plain jacket). That way I do not intensely smell of cigarette smoke and have a pleasant lynx smell instead. (lynx is a brand of deoderant for those who have not heard of it).
The last company that I worked for actually had it in the contract that you had to quit smoking and not smoke at any stage while employed, both at work and off duty as it detracted from the image of "a positive role model within the health community."
And believe it or not, as a smoker, when I get busy at work, I actually forget that I need the nicotine as I am too busy to care, so it is actually very rare that I have the opportunity to sneak off for a quick "cancer break" any way.