This study explored characteristics of college student hookah smokers and evaluated the presence of hookah references displayed on university students’ public Facebook pages. More than one-quarter of college students reported smoking hookah and this prevalence estimate is consistent with the national estimate of hookah use among young adults enrolled in college.25 To the authors' knowledge, this is the first study to survey college students about what substances they smoke in their hookah. The majority of hookah smokers reported smoking tobacco in their hookah, yet more than 20% reported experience with using marijuana or hash in their hookah. These findings support the rising popularity and diversity of hookah use among young adults in the USA.

The finding that so many college students are smoking hookah, and specifically smoking tobacco in their hookah, is cause for clinical and public health concern. Although the health effects of hookah have not been studied nearly as extensively as cigarettes, smoking tobacco in a waterpipe is associated with negative health outcomes similar to those associated with cigarette use. Studies compare hookah to cigarettes and illustrate that both forms of tobacco use expose smokers to toxicants associated with cardiovascular and lung disease, including carbon monoxide and polycyclic aromatic hydrocarbons.3 26 Further, hookah use significantly increases one's risk of lung cancer, respiratory illness, low birthweight and periodontal disease.27 Lastly, preliminary research shows hookah use may be associated with nicotine dependence and could be a gateway drug to cigarette smoking.3 28

These negative health consequences of hookah use are compounded by the many misperceptions and incorrect beliefs and attitudes held by hookah users. Many hookah smokers underestimate the health risks and addictive properties of hookah use. In contrast to the published harms of hookah use, college students and young adults believe smoking tobacco in a waterpipe is less harmful and less addictive than cigarettes and believe they can quit anytime.29 30

Similar to other studies, the results of this study suggest that hookah users were more likely than non-hookah users to engage in substance use (separate from their hookah smoking) such as marijuana, cigarettes and other psychoactive drugs.10 31 32 Due to the cross-sectional nature of this study, it is impossible to determine the temporal sequence of hookah smoking and the use of other substances. However, it may not be surprising that hookah smokers also engage in other substance use behaviours. Previous research supports that engagement in one risk behaviour is often associated with an increased likelihood of engaging in other risk behaviours.33 This may be especially true for hookah, cigarettes and marijuana, all different means of smoking. It may be that once a college student decides to engage in a smoking behaviour, they may be open to a variety of smoking behaviours. These results suggest hookah prevention efforts may be paired with other substance use and general smoking prevention strategies.

The findings that one in five hookah smokers smoke marijuana in their hookah and that hookah smokers are more likely to smoke marijuana separately compared to non-hookah smokers, are important for two reasons. First, given that many college students maintain that hookah smoking is a safe alternative to cigarette smoking and that hookah smoking does not constitute ‘smoking’,11 it is possible that these young adults differentiate between methods of tobacco use. Similarly, college students may have altered perceptions of the safety of smoking marijuana in a hookah. Second, given the integration of hookah smoking into the social scene on college campuses,11 it is possible that marijuana may also experience a sort of social promotion when associated with hookah. This may have implications for intervention strategies and further work is needed to explore these ideas.

To the best of the authors’ knowledge, this is also the first study to investigate hookah use using Facebook. These findings show more than 5% of college student profiles display references to hookah on Facebook. While this percentage does not compare with the prevalence of smoking hookah, hookah references on SNSs have not yet been extensively studied. Other work illustrates that adolescents display references to other risk behaviours such as alcohol and substance use on their SNS profile.21 These displays of various risk behaviours may represent engagement in that behaviour, consideration of engagement in the behaviour, boastful claims or nonsense.21 College students who display references to intoxication or problem drinking on their Facebook profile were more likely to meet clinical criteria for problem drinking compared to those who do not display such references.34 In addition, adolescents interpret alcohol displays on SNSs to be influential and valid representations of alcohol use.35 Thus, these displays are meaningful. Given the social nature of hookah smoking, the social dimension of Facebook may be a salient factor in popularising hookah use. Since students mainly initiate and practice hookah use with friends, Facebook may allow them to find such friends. Further research exploring the presence and meaning of specifically hookah displays on Facebook profiles is necessary.

There are several potential limitations to this study. First, participants were recruited from only two universities and the study sample included very few minority and no African American participants. While the study sample is demographically representative of the student population at the two selected universities, it is possible that these two universities do not provide a representative sample of the US college population. The literature suggests that after students of Arab descent, Caucasian students, followed by Asian students have the highest reported prevalence rates of smoking hookah.11 Therefore, given that the participants were selected from large geographically distinct state universities and that these prevalence estimates are consistent with other studies’ estimates, this suggests that these results may be generalisable to the US college population. Second, only profiles from one SNS were evaluated and participants were limited to those who maintained a public Facebook profile and allowed their phone numbers to be listed in either their university directory or on Facebook. The extent to which these findings could be generalised to profiles that have their security set to private, to profiles on other SNSs, or to younger adolescent populations is not known. Third, it is important to note that SNS profile privacy settings are not permanent; profile owners may change their privacy settings at any time or to reflect what security upgrades are offered by Facebook. It is unclear as to whether profile owners who maintained a private profile at the time of this study would be more likely, or less likely, to display hookah references. Lastly, the cross-sectional design of this study precluded determining the temporal sequence of smoking hookah and engagement in other substance use. Future research including longitudinal studies is needed to explore these associations, especially the potential role of hookah as a gateway to cigarette smoking.

Despite these limitations, the findings have important implications. First, this is the first study to illustrate that hookah use goes beyond tobacco. College students also smoke marijuana and hash in their hookah. With this understanding, future prevention and intervention methods may pair existing tobacco and marijuana strategies when targeting college hookah smokers. Second, hookah use is also emerging on Facebook profiles, which may help promote the illusion that it is a socially acceptable behaviour and safe alternative to cigarettes. To determine if hookah references aid in the promotion of hookah smoking among college students, more work is needed to explore the presence and meaning of hookah displays on Facebook. Further, similar to studies which have found Facebook to be feasible for identifying college students at risk for problem drinking, more work is needed to determine if SNSs may also be helpful for screening and identifying college students at risk for or engaged in hookah smoking.