In a new study, arteries in rats that inhaled secondhand marijuana smoke for one minute carried blood less efficiently for at least 90 minutes. Similar exposure to secondhand tobacco smoke caused blood vessel impairment for 30 minutes.
“While the effect is temporary for both cigarette and marijuana smoke, these temporary problems can turn into long-term problems if exposures occur often enough and may increase the chances of developing hardened and clogged arteries,” said Matthew Springer, Ph.D.
The increasing number of states legalizing medicinal and recreational marijuana, along with increasing potential for corporate expansion within the cannabis industry, makes it important to understand the health consequences of secondhand marijuana smoke exposure, Springer said.
“There is widespread belief that, unlike tobacco smoke, marijuana smoke is benign,” he said. “We in public health have been telling the public to avoid secondhand tobacco smoke for years. But we don’t tell them to avoid secondhand marijuana smoke, because until now we haven’t had evidence that it can be harmful.”