Cause and Effect: Researchers note that surgeons and anesthetists favor operating room opiates for drugs of abuse and conclude they're getting addicted from the fumes in the OR:

Similar associations have been noticed before, and previously these results have been put down to the fact that anaesthetists and surgeons have easier access to opiates than most of their colleagues.

But the University of Florida team, which sampled air from operating rooms, say that traces of gaseous anaesthetics could be the cause. In McAuliffe's paper, for example, fentanyl was found near the needles used to inject the drug and in the air exhaled by patients.

Mark Gold, a psychiatrist at the University of Florida who has pioneered studies of the exposure hypothesis, says that research into other addictions suggests that the aerosolized opiates could be the root of the problem. Children of smokers are known to be more likely to take up smoking, for example. One cause is thought to be changes to areas of the brain involved in addiction, brought on by exposure to smoke.

Well, anything is possible, but wouldn't a surgeon or anesthetist have to have some awareness of what it is he's impercetibly inhaling in order to step up to actively abusing that very same substance? Easy access would seem to be more plausible. And as for children of smokers, it's far more likely that their smoking patterns are influenced by their adult role models than by second hand smoke's addictive qualities.