Q: I am a non smoker and a teetotaller. However, I smoked a hookah recently, which I was told has no tobacco and no tar. However, the first few times I inhaled it, I felt some irritation in my throat. I would like to know how safe are these hookahs and whether they have any associated health risks?

A:Although, the health damaging effects of cigarette smoking have been thoroughly studied the risks of other forms of smoking are still awaiting definitive findings. Intuitively, one would expect the use of water pipes to be far less hazardous, although a dose dependent risk might still be a concern. Thus an occasional smoke is unlikely to be of harm and may be of benefit if it improves social relationships and quality of life. In contrast, perpetual smoking is likely to eventually harm the user and may pose a health hazard to the local environment of those exposed to second hand smoke.