i've put the theory to the test with a few hundred thousand cigarettes and too much booze when I was younger. i had chronic chest pain a few years ago (turned out I pulled a muscle in my chest) but my GP sent me to hospital in case i had a heartache as the pain was so severe. hooked me up to an ecg, breathing asparatus, x rayed my lungs and a few other things. was given a clean bill of health and was told, "You've clearly never smoked, your lungs are crystal clear and your heart is excellent." i had been smoking about a pack and half a day - my wife was appalled. i don't know how they couldn't smell it.