Fig. 1.

A narghile waterpipe. The waterpipe consists of a head, body, water bowl, and hose. A moistened, flavored tobacco mixture is placed in the head and covered with a piece of perforated aluminum foil. Burning charcoal is placed on top of the aluminum foil to provide the heat needed to generate the smoke. When a user takes a puff, air and hot charcoal fumes are drawn through the tobacco mixture, and eventually through the water bubbler, hose and mouthpiece. Between puffs, sidestream toxicants are emitted directly from the head to the surrounding environment. Similar quantities of charcoal and tobacco mixture are consumed in a typical 1 hour café use session (Figure adapted from Monzer et al. (2008)).