i don't think balding has anything to do with alcohol, because some of the people i know, drinkers and non-drinkers, still get thinning hair. still, drink occasionally.
as for smoking, it is possible it causes hair loss. yes there are non-smokers who also experience balding, but remember, smoking is a global addiction. this means that no matter where you go, you get to inhale second hand smoke. second hand smoke is as detrimental as first hand smoke. this is a fact.
i do hope smokers will realize that their smoke also poisons not only themselves but also non-smokers. so trying to stop smoking is a big step in helping the community and our environment. apology for those who may take this as an offence.