To convince and to inform: ethical issues in public health campaigns.

inhaled; hence the astonishing volume produced in each puff.(2) This last item, related to the relationship between the assimilation of nicotine and the volume of inhaled smoke is quoted in the last paragraph of that topic in the article in question. However, in the same passage, we read “the water used in the narghile absorbs some of the nicotine (approximately 5%), narghile smokers are nevertheless exposed to sufficient quantities of the drug to cause dependence”. If we take into account the data provided in the fourth paragraph of the section, according to which “the composition of the tobacco used for this modality of consumption has no standard, and its nicotine content is estimated at 2-4%, compared with 1-3% for the tobacco used in cigarettes”, we can conclude that the quantity of nicotine in the smoke after water filtering would still be greater than in the cigarette (95% × 2-4%, resulting in a value between 1.9% and 3.8%). Therefore, narghile smokers would not inhale more smoke; on the contrary, they would, in theory, inhale less smoke. In fact, the article from which the information on filtering was extracted, more recent than the one by Shihadeh et al.,(1) does not reach the same conclusion that the latter does. The abstract of the former reads as follows: “a single session of waterpipe use produced a urinary cotinine level that was equivalent to smoking two cigarettes in one day”.(3) In short, in one of the articles cited it is stated that a narghile session can be the equivalent of 100 cigarettes or more, and it is justified by the hypothesis that there is a compensation between the nicotine filtering and the volume of each puff; whereas the other article discredits that justification, as it is stated that the water filters little nicotine, and the conclusion is that a full narghile session is the equivalent of smoking 2 cigarettes instead of 100 or more, in terms of the nicotine absorbed. Therefore, the information regarding the volume of smoke and the To the Editor: