http://www.sciencedirect.com/science/article/pii/S037842741200063XAlthough TCDD is present in small amounts in the environment, it exists at high levels in cigarette smoke. Elevated TCDD levels in the body have never been linked to anything other than cigarette smoke and the military compound Agent Orange. Hsu remains encouraged by his research, with some in vitro studies suggesting that the toxin down-regulates certain genes that are important for osteogenesis, or bone healing.As long as the predominant theory is that nicotine is the main cause in the disruption of bone healing, many surgeons will continue to advise that even supplements like a nicotine patch can’t be used after surgery. Without such aids, no-smoking compliance rates decrease as smokers are forced to give up the habit cold-turkey. Hsu believes that if his research establishes TCDD as the root cause, nicotine supplements would be OK for patients to use, likely increasing no-smoking compliance rates and outcomes in the process.
Hmm
I'm reserving judgement,but..........
http://www.who.int/mediacentre/factsheets/fs225/en/
