BackgroundThe number of waterpipe tobacco smokers has been increasing worldwide. Smokers can be exposed to a number of toxicants, some of which are metals. The aim of this study is to quantitatively determine if the water filtration stage of the waterpipe smoking process successfully decreases exposure to Bi, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, V, and U.MethodsFour samples of commercially available tobacco (Moassel) were compared in terms of the total amount of metal contained within the fresh tobacco sample and the amount of metal distributed into each compartment of the waterpipe after a smoking session.ResultsFor all metals analysed, the concentration of metal ‘filtered’ out during the water bubbling stage is around 3% (±1%) of the total metal.ConclusionsIt can be concluded that this small fraction would not protect the user against exposure to the majority of the potentially toxic metals.