When we think of the exposure sources of secondhand smoke, we usually consider parents, grandparents, or other child providers using conventional cigarettes and other tobacco products in the home or car. But now with the increasing legalization of recreational marijuana in some states, one wonders what the prevalence of secondhand smoke might be due to care providers using cannabis in the home setting. To answer that question, Goodwin et al. (10.1542/peds.2017-3506) used data from an annual national cross-sectional study that looked at various associations between parental cigarette smoking in homes with children and their cannabis use in the past month or months, studying trends over time from 2002-2015. The authors found that past-month cannabis use increased over the 13 year studied from 4.9% in 2002 to 6.8% in 2015. While this may not be a surprise, the fact that cigarette smoking decreased in those same homes over that time from 27.6% to 20.2% may be a finding you were not expecting. Of note, the increase in cannabis use was far greater if parents were also cigarette smokers than if they were not. The only good news from this study is that if you combined either cigarette smoking in the home or cannabis smoking, the overall percentage using either of these two smoking items decreased from 29.7% in 2002 to 23.5%.
The bottom line of this study is a bit reminiscent of that carnival game “Whack-a-Mole,” whereby when one sees cigarette smoking rates declining, be ready to see cannabis efforts increasing at the same time. Given the similarities of the potential toxins contained in both cigarette and marijuana smoke, neither of these home smoking practices is beneficial to the health and well-being of the children who also live in these homes. While the study findings are a bit of a drag, they remind us that asking about secondhand smoke, due not just to tobacco but cannabis, may be something we have not been doing as much as we need to be doing. Check out this study and then think how you can do even more to reduce second hand smoke exposure to both tobacco and cannabis in your practice.