In parallel with tobacco regulations, cannabis control policies appear to impact cannabis use. In its Global Drug Report 2020, the United Nations noted that in jurisdictions that have legalized cannabis use, frequency of cannabis use has subsequently increased . Analysis of data for a US representative sample of adults with children living in the home found cannabis use to be more common in states that had legalized recreational cannabis use , possibly leading to increased in-home cannabis smoking and concomitant exposure of non-smokers. An overview of recreational cannabis use regulation by country is presented by Wikipedia on their “Legality of cannabis” webpage . The data demonstrate a substantial diversity across countries regarding whether cannabis has been legalized or decriminalized, the venues restricted, level of enforcement, and consequences for violations. In the US, a growing number of states have legalized cannabis for recreational or medicinal purposes, adding another layer of complexity. As with smoke-free ordinances for tobacco use,marijuana grow system the level of constraint imposed by cannabis control policies is likely to affect home smoking rules and behaviors.
While information about rates of in-home cannabis smoking and in-home exposure to cannabis SHS are not yet available, there is evidence that the perception of health risks associated with cannabis smoke is lower than for tobacco smoke . Furthermore, early evidence from US studies of household rules about in-home smoking suggests that 59% to 71% of people who used cannabis allow cannabis smoking inside their home, while just 26% allowed tobacco smoking in their home . With lower rates of in-home tobacco smoking, lower perceived risk of cannabis smoke, and relatively lax household rules surrounding in-home cannabis smoking, we expect higher rates of in-home cannabis smoking than in-home tobacco smoking. To test this hypothesis, we used data from over 100,000 adults from 17 countries to compare in-home cannabis and tobacco smoking among 2019 Global Drug Survey respondents who use cannabis only, tobacco only, both tobacco and cannabis, or neither. Data for this cross-sectional analysis were from the 2019 GDS survey.
It was designed by substance use experts to assess existing and nascent patterns of substance use worldwide among annual samples of sentinel, more involved drug-using populations . The GDS promotes their survey via media partners from around the world such as HUFFPOST, VICE, MixMag, Fairfax Media, and The Guardian. They also use targeted social media campaigns on Facebook, Twitter, Reddit and drug discussion forums. The 2019 survey was available in 19 languages and collected data from over 35 countries. The core survey assessed demographics, drug use and consequences and in 2019 took about 15–20 min to complete—additional sections on psychedelic therapies, cannabis vertical farming edibles, and sex and drugs took an additional 25 to 30 min. No financial incentive was provided. Participants confirmed they were ≥ 16 years old, but there were no other eligibility requirements; participation was open to individuals regardless of participation in any prior year administration of the annual GDS. For the current study, eligible participants included 123,814 persons who took the GDS between October 29, 2018 and January 10, 2019 and reported past-year use of at least one of 31 psychoactive drugs, including the most commonly used: tobacco, alcohol or cannabis.
Consistent with previous GDS analyses, only countries that had greater than 1,500 respondents were included so that country-specific analyses could be conducted—therefore data from 17 countries were used, excluding 14,178 participants. Participants were also excluded if they were missing data on cannabis use, tobacco use, or in-home smoking of cannabis or tobacco . The remaining 107,274 comprised our final analytic sample. Ethical approval was obtained from the separate institutions: Joint South London and Maudsley and Institute of Psychiatry NHS , the University of Queensland and The University of New South Wales . See Barratt et al. for more information on the methods of the GDS. Participant characteristics were summarized for the total sample and stratified by the four tobacco and cannabis use groups. Group differences were tested using Pearson chi-square or t-tests, as appropriate.