Children whose parents regularly smoke or vape cannabis appear to be more susceptible to respiratory illnesses, such as common colds or bronchiolitis, according to a new study in the journal Pediatric Research. After surveying almost 1,500 parents at a children’s hospital in Colorado, the study authors concluded that such infections appear to occur more commonly in kids who are routinely exposed to second-hand cannabis smoke than those who are not.
Colorado was the first state in the US to legalize recreational cannabis use, and therefore represents something of a testing ground for health officials attempting to tease out the potential benefits and harms of widespread pot use. Of the parents who participated in this particular study, 5.2 percent said they smoked or vaped only cannabis, while 5.4 percent reported smoking both cannabis and tobacco, and 14.3 percent smoked only tobacco. Of those who consumed cannabis, 95 percent were classified as regular users, meaning they smoked at least once a week.
Those who admitted to using cannabis – whether on its own or in conjunction with tobacco – reported a higher incidence of viral respiratory infections among their children, with these kids catching an average of 1.31 colds or other similar illnesses per year. In contrast, children whose parents don’t consume cannabis or tobacco only experienced 1.04 infections per year.
Interestingly, children whose parents smoked only tobacco were no more likely to catch respiratory infections (1.0 infections per year) than those whose parents claimed not to smoke at all. However, tobacco smoke was associated with an increased number of visits to the emergency room, while this was not the case for second-hand cannabis smoke.
Likewise, children of pot-smoking parents did not appear to suffer from other conditions that are known to be linked to second-hand tobacco smoke, such as ear infections or asthma attacks.
“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,” explained 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.”
As the researchers point out, however, these observations do not prove any causal link between second-hand cannabis smoke and respiratory infections, which means more studies will be needed before concrete conclusions can be drawn. Furthermore, their decision to include vaping as a source of second-hand smoke is somewhat controversial, giving that this does not produce any actual smoke.
Nonetheless, studies have indicated detectable levels of tetrahydrocannabinol (THC) – the main psychoactive component in cannabis – in the air following vaporizer use, which is why the authors chose to include this form of ingestion in their study. In spite of this, they concede that their results “may have been slightly different had we separated out caregivers who indicated vaping as their method of choice.”