A critique of recent hypotheses on oral (and lung) cancer induced by water pipe (hookah, shisha, narghile) tobacco smoking.

The medical hypothesis that the mainstream smoke (the one inhaled by the user) from "water pipes" (mainly: shisha, hookah, narghile) causes oral cancer is certainly acceptable. However, most of the recent reviews on this issue, including an attempt to develop an hypothesis for hookah carcinogenesis, have not cited key references of the world available literature which, so far, generally do not support such an hypothesis. Besides, the proposal is biased since it is apparently an adaptation of the cigarette model whereas cigarette and hookah smokes are, chemically to start with, completely different. Furthermore, all water pipes, despite their striking varieties and the consequences on the chemical processes, are, according to the same cancer-hypothesis, considered as one. The reason is the use, in the cited mainstream literature, of a nominalism ("waterpipe", often in one word) which does not allow any distinction between devices. This critical article suggests to take into account all the peculiar characteristics into consideration in order to come up with another (or several other) carcinogenesis model(s). "Firmly believ[ing] that water pipe smoking can provoke lung cancer as well as oral cancer", based on what may be seen as a rather reductionist view of the issue, is not enough.