Can exposure to second-hand cannabis smoke be harmful?

Abstract

Background: Canada legalized the use of cannabis for recreational purposes in October 2018. To ensure public health and safety, the Cannabis Act was also introduced by the Government of Canada in 2018. This Act does not permit smoking cannabis in restricted areas. However, people still smoke in public places, thus, exposing the general public to second-hand cannabis smoke (SHCS). As cannabis is an emerging topic and the legalization of cannabis for recreational use is still recent, the long-term health effects of SHCS is unknown. However, the perceived immediate health impacts of SHCS can be examined to better understand its long-term health effects on human body. Methods: An online survey was conducted, targeting residents of British Columbia (Canada) with differing smoking status, gender, education level and age groups, to determine the differences in perceived immediate health impacts and/or concerns from exposure to SHCS. The survey consisted of sixteen questions divided into three sections, covering demographic information, exposure to SHCS and perceived immediate health impacts and/or concerns about SHCS. The data was analyzed using Chi-square tests. Results: A total of 159 participants took part in this survey. The results showed no associations between exposure to SCHS and perceived immediate health impacts. This could be due to the legalization of cannabis for recreational use being so recent. However, headaches, coughing, chest tightness and irritation to eyes are a few perceived immediate health impacts experienced by 41 out of 139 participants (30%) after exposure to SHCS. This study also found that age and place of exposure may not affect the likelihood of experiencing perceived immediate health impacts. However, females and cannabis non-users are more likely to experience perceived immediate health impacts compared to males and cannabis users, with p = 0.01 and 000003, respectively. Conclusion: The findings of this study identified a few perceived immediate health impacts associated with SHCS such as headaches, coughing, chest tightness and eye irritation. However, the study indicates that there is an inadequate scientific knowledge regarding the long-term health effects from exposure to SHCS as well as the variation in health effects among different age groups, gender, smoking status and place of exposure. As a result, precautionary steps should be taken now to minimize its ill-effects in future. The government should provide tools to aide researchers and health care professionals to conduct in-depth research on SHCS and its health effects. Moreover, initiatives should be taken to educate general public about cannabis smoke, its composition, associated health effects and legislation.