Allowing cigarette or marijuana smoking in the home and car: prevalence and correlates in a young adult sample.

Given the increased marijuana use, negative health consequences of marijuana secondhand smoke exposure (SHSe) and dearth of research regarding marijuana SHSe in personal settings, we examined the prevalence and correlates of allowing marijuana versus cigarette smoking in personal settings among 2002 online survey respondents at two southeastern US universities in 2013. Findings indicated that 14.5% allowed cigarettes in the home, 17.0% marijuana in the home, 35.9% cigarettes in cars and 27.3% marijuana in cars. Allowing cigarettes in the home was associated with younger age, racial/ethnic minority status, living off campus, personal marijuana use, parental tobacco use and positive perceptions of cigarettes (P < 0.05). Correlates of allowing marijuana in the home included older age, not having children, living off campus, positive perceptions of marijuana and personal, parental and friend marijuana use (P < 0.05). Correlates of allowing cigarettes in cars included personal cigarette and marijuana use, parental tobacco and marijuana use, more cigarette-smoking friends and positive perceptions of cigarettes (P < 0.05). Correlates of allowing marijuana in cars included being non-Hispanic black; positive perceptions of marijuana; and personal, parental and friend marijuana use (P < 0.05). Interventions must target distinct factors influencing policies regarding cigarette versus marijuana use in personal settings to address the consequences of marijuana and cigarette SHSe.