In order to assess the potential acute and long-term effects associated with e-cigarette use and to guide future assessments, a comprehensive review of the literature was conducted, focusing on the potential harmful effects of e-cigarette use, more specifically, in vitro, in vivo and clinical studies were assessed.

The literature results show a compelling story. Over 14,000 e-cigarette manuscripts from 2016 onwards were identified upon an initial search. Once refined using targeting information, 300 relevant manuscripts were identified and grouped. Only 13 % of these manuscripts proposed that e-cigarette use is comparable, more hazardous or represents a new hazard compared to traditional cigarette smoking. The remainder (87 %) all present a consistent story; in that they substantiate e-cigarette use to be significantly less hazardous than cigarette smoking or that no risk was identified at all in their use. The latter is consistent with the e-cigarette position in the risk continuum of nicotine products, as being substantially less risky than cigarette smoking.

Inconsistencies in reporting, lack of dosimetry/chemical analysis of test articles, variable smoking regimens, lack of cigarette smoke context and specific details of e-liquid/aerosol formulations, ultimately limited to overall use and application of many of the reviewed datasets. Data suggests that addressing these study reporting inconsistencies would yield more powerful and applicable datasets on which appropriate conclusions can be drawn, thus limiting the overall misrepresentation of study outcomes.