What is more, researchers found that it may take three times as long for blood vessel function to recover after inhalation of secondhand marijuana smoke, compared with inhalation of secondhand tobacco smoke.
Senior author Matthew Springer, Ph.D., professor of medicine in the Division of Cardiology at the University of California-San Francisco, and colleagues report their findings in the Journal of the American Heart Association.
The harms of exposure to secondhand tobacco smoke are well established, and these include immediate damage to the heart and blood vessels.
But according to the research team, little is known about the harms that may arise as a result of exposure to secondhand marijuana smoke.
To find out, Springer and colleagues exposed rats to either secondhand tobacco or marijuana smoke for 1 minute.
The team assessed the blood vessel function of the rodents before and after exposure to each form of smoke. Specifically, they looked at how the smoke impacted the blood vessels' ability to transport blood, and if impairment occurred, how long it lasted.
Lengthy blood vessel recovery with secondhand marijuana smoke
The researchers found that exposure to both types of smoke impaired the rats' blood vessel function, but secondhand marijuana smoke appeared to have a more damaging effect than secondhand tobacco smoke.