Smoking cigarettes may be less common among youth today than in previous generations, but another puffing habit has taken its place: waterpipes, also known as hookahs or shishas. According to a new study by the University of Montreal and published in the journal Pediatrics, these instruments, which originated in India, are popular among young adults. Roughly one-quarter of Montrealers between the ages of 18 and 24 have smoked tobacco using a waterpipe over the last year. What’s more, five per cent had done so at least once over the last month. The most frequent users were found to be Anglophone males living on their own. Waterpipe users also tended to be most common among people who also use cigarettes, marijuana, alcohol and other drugs. This data is troubling because, contrary to the popular perception among many youth, waterpipe smoke does contain dangerous chemicals such as nicotine, carbon monoxide and tar—even more so than cigarettes.