It's been quite a few years since the newspapers published a very small article (they didn't want to give it too much publicity) on a study that was done that concluded smokers are your best workers. And yep, the guy who did the study was disappointed in the results since he was a non-smoker. His conclusion was that "smokers are addictive personalities so they must get addicted to work".

But it's another reason I don't believe all the nonsense the medical profession has put out. I had many employees (up to 153 at a time) working for me for many years. I had both police officers and non-sworn (civilian) personnel, and, while there are exceptions to every rule, the smokers were generally the ones who showed up for work every day and did their job. It was the non-smokers who called in sick, kept their sick leave used up, and were frequently interested only in their paycheck.
Personally, I had so much sick leave accumulated that I could have taken off 2 or 3 days a month for years and still retired with the maximum accumulation.