**4. Discussion**

This study showed the e ffects of a research study linking cancer in mice to vaping on Twitter. The study was tweeted by several mainstream media outlets and dominated discussions of e-cigarettes on Twitter. The study, however, was questioned by several experts as they noted that the study conducted on mice could not be generalised to humans. Our study highlighted the impact of academic research on Twitter when it is disseminated through the mainstream media. The publication of the study caused grea<sup>t</sup> concern over the safety of e-cigarettes on Twitter, and users of the platform were quick to point out that e-cigarettes were still a much safer alternative to traditional smoking. For instance, health authorities such as the National Health Service in the United Kingdom still noted that e-cigarettes contained a fraction of the risk when compared to that of traditional cigarettes [19]. However, the publication of the study linking cancer to mice may have incorrectly been interpreted and understood by some members of the public who would now believe that e-cigarettes were just as unsafe and/or more unsafe when compared to traditional tobacco based cigarettes. Current advice provided by Centers for Disease Control [20–22] notes that e-cigarettes are likely to be safer than smoking traditional cigarettes. Our recommendation to health authorities is to o ffer guidance to the public in order for citizens to make informed decisions about whether e-cigarettes are safe to consume. A key aspect of assessing whether vaping is safe depends on whether an individual is already engaged in using traditional cigarettes and/or rolled tobacco products. However, information disseminated to consumers around the safety of e-cigarettes can be confusing and vague. Moreover, we found that Twitter users tended to be unsure about the safety of e-cigarettes. Henceforth, based on a review of the literature and the advice provided by the Centers for Disease Control, the National Health Service (NHS), and Cancer Research UK [20–22], we developed a flowchart, as shown in Figure 3, that could be utilised by consumers and medical professionals when making a decision about whether e-cigarettes are likely to be safe or unsafe based on their circumstances.

**Figure 3.** Flowchart based on current by Centers for Disease Control, the NHS, and Cancer Research UK [20–22].

By analysing public comments on Twitter, we were able to identify potential points of confusion by consumers, and combining our results with that of current medical advice led to the development of the flowchart above. Social media may be a source of information for a subset of the population, and it is important to analyse this information from a public health surveillance perspective. Our findings can also be contrasted with previous empirical work in this area. A study published in 2018 [23] conducted an analysis of e-cigarette discussions on Twitter from 2012 to 2015, which examined the reasons for using such devices. The study found that one of the most popular reasons for using e-cigarettes was to quit traditional cigarettes, and Twitter users were positive towards e-cigarette devices. Moreover, they found that 43% of Twitter users were able to give up traditional cigarettes, which demonstrated the potential of e-cigarettes for smoking cessation. The findings of this study were similar to our present study, which also found that there was a sizeable "pro-vaping" community on Twitter. A further study [24] published in 2014 looked at a specific case study containing tweets for and against public health policy related to the Chicago Department of Public Health. This study also found pro- and anti-e-cigarette views such as that they promote smoking cessation, but also that they are harmful and foster nicotine addiction. A further study in the United Kingdom [25] surveyed 3538 current and 579 recent smokers in November and December 2012. It was also found that there were mixed views among the public about whether e-cigarettes were more or less harmful than traditional cigarettes, with a number of citizens unsure of their safety at the time. These results further highlight the need for easy-to-understand guidance for consumers, and our flowchart developed above will be of interest to health authorities.
