Study: Are children at risk from secondhand cannabis smoke at home?

Legalisation of recreational and medical cannabis in the US was linked to an increase in consumption among adults with children at home, a study has found.

Researchers in the US have called for more public health awareness of the potential risks of secondhand cannabis smoke exposure to children in the home.

According to a new study by Columbia University Mailman School of Public Health, Columbia Irving Medical Center and the City University of New York, among adults with children living in the home, cannabis use was more common in states with legalised cannabis use.

Legislation for recreational and medical use were both linked with significantly higher prevalence of past-month and daily cannabis use. 

Until now, most tobacco control and harm reduction efforts protecting youth from exposure to secondhand tobacco smoke focused on parental cigarette smoking, ensuring smoke-free homes, and not smoking in the presence of children. 

The potential risks of exposure to secondhand cannabis smoke and education on the merits of protecting youth from exposure to secondhand cannabis smoke have received little attention in the cannabis legalisation effort, according to epidemiologist Renee Goodwin, PhD, MPH, at Columbia Mailman School of Public Health and lead investigator.

“If legalisation for medical or recreational purposes has increased cannabis use among adults living in the home with children, adults deserve education about the risks of secondhand smoke to youth, as well as information on any other risks to their children associated with parental cannabis use,” said Goodwin

 “In contrast to cigarettes, there are no public health or clinical guidelines for parents designed to address or educate about best practices for use of cannabis toward avoiding or reducing harmful exposures of secondhand smoke to children’s health.”

The researchers analysed data from the 2004-2017 National Survey on Drug Use and Health, an annual representative survey on substance use and mental health of individuals ages 12 and older.

They determined past-30-day cannabis use and daily cannabis use by age, gender, annual family income, and educational attainment as well as cannabis legalisation.

In states where cannabis is legal for recreational purposes, 12 percent of the adults reported past-month use, and four percent used daily, say the findings, which are published in the journal Addiction.

For states with medical cannabis laws, the percentage of users in the month dropped to nine percent, and to six percent in states without legalisation laws.

 On a daily basis, adults reported using at 4.2 percent, 3.2 percent, and 2.3 percent, respectively.

Legislation of recreational use was associated with significant jumps in cannabis use among adults with children living in the home. 

The effect of legalisation for medical use was concentrated more among parents who are older, with higher income and education levels. 

While increases in states with recreational legalisation were observed consistently across all demographics.

Since secondhand cannabis smoke exposure has a number of undesirable health risks for youth, and adolescents with parents who use cannabis are at increased risk of cannabis use themselves, say investigators.

According to Goodwin, estimating the degree to which cannabis use has increased among adults with children in the home, is critical to inform the allocation of resources for prevention and intervention efforts. 

“As an increasing number of states legalise cannabis for medical or recreational use, educational efforts to reduce children’s exposure to secondhand cannabis smoke may be essential to protect children in this era of new or rapidly shifting cannabis policy,” Goodwin added.