Second-hand Cannabis Smoke Exposure Associated with Respiratory Infections in Children
The children of regular cannabis users who smoke or vape may come down with viral respiratory infections more often than those whose parents do not smoke, according to new research.
In a new study published in the journal Pediatric Research, researchers found a statistically significant association between a child’s exposure to second-hand cannabis smoke from a parent and an increased likelihood of catching a viral respiratory infection – such as the common cold or bronchiolitis – within the last 12 months.
The researchers say that these findings, while they are observational and not necessarily causational, do highlight the need for increased awareness and research into the possible negative impacts of second-hand cannabis smoke exposure, especially as more jurisdictions around the world consider legalizing cannabis use.
Second-hand cannabis smoke may carry different risks to tobacco smoke
In the new study, researchers from the Wake Forest School of Medicine and Children’s Hospital, Colorado, surveyed nearly 1,500 parents and guardians who visited the hospital over a 20-month period.
Of the parents and caregivers that participated in the survey, roughly 5 percent reported regularly using only cannabis (at least daily or weekly) and 14 percent regularly smoked only tobacco, with a further 5 percent using both cannabis and tobacco. During the survey, parents were asked to record different demographic data such as their age and their child’s age, their own education level, and current drug use. The parents were also asked to report how often in the past 12 months their child had experienced various known tobacco smoke exposure-related illnesses, as well as the number of visits made to the emergency department or urgent care.
The researchers found that the children whose parents smoked or vaped only cannabis experienced more viral respiratory infections in the year prior to the survey than those whose parents did not smoke at all. Notably, other risks known to be associated with second-hand tobacco smoke – such as ear infections or asthma attacks – were not reported more frequently in the children of frequent cannabis users.
“The negative impact that exposure to second-hand tobacco smoke can have on children’s health has been extensively studied but the impact of second-hand marijuana smoke on young children is unclear,” said study author Adam Johnson in a statement.
“Our findings identify the potential for increased respiratory infections in children exposed to second-hand marijuana smoke. This could have significant healthcare implications as more states in the USA move towards legalizing recreational marijuana use.”
Study cannot prove causation, but does offer new insight for public health messaging
In addition to the different health outcomes seen in the children of cannabis users, tobacco users, and those who use both or neither substance, the researchers also observed some interesting demographic differences between the four parent groups.
Those who only smoked cannabis were more likely to be younger, educated to a higher level, have a higher income, and be less likely to identify as Hispanic than those who only smoked tobacco or who did not smoke. Similarly, parents who smoked cannabis and tobacco also tended to be younger and were less likely to identify as Hispanic than non-smokers. But this group were also more likely to report lower income and education levels than the non-smokers, compared to those who only smoked one substance.
“Our findings highlight the prevalence of marijuana use among parents and caregivers and indicate which children may be more likely to be exposed to second-hand marijuana smoke in a US state where recreational and medicinal marijuana use is legal,” said Johnson.
“These findings could be used to help target and shape public health messaging aimed at parents and caregivers in order to raise awareness of the potential negative impacts that second-hand marijuana smoke exposure can have on children’s health.”
The researchers stress that the observational nature of the study means that these associations between parental and caregiver drug use and the frequency of viral respiratory infections cannot be taken as a causal relationship. They also note that their study is limited by virtue of only surveying parents and caregivers in a single US state, and therefore may not be generalizable to other locations where cannabis is legal, or indeed other locations where cannabis use is still prohibited.
However, these observed associations do still have a place in informing future areas of research. The scientists behind this study suggest that future work could explore the impact of parental cannabis use on children when other non-smokable cannabis products are used, such as edibles or topicals.