The danger of secondhand smoke from tobacco cigarettes is well documented. However, new research proposes exposure to secondhand marijuana smoke may be just as hazardous.
A study, recently published in the Journal of the American Heart Association, found secondhand marijuana smoke may harm cardiovascular function. Researchers subjected rats to the smoke for one minute, and immediately after, noticed reduced blood vessel function comparable to exposure to tobacco smoke.
The rodents who inhaled the marijuana smoke also experienced the cardiovascular effects much longer than when exposed to tobacco smoke. The arteries carried blood less efficiently for 90 minutes after the rats took in secondhand marijuana smoke, while the secondhand tobacco smoke caused impairment for only 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., study senior author and professor of medicine at the University of California. “Arteries of rats and humans are similar in how they respond to secondhand tobacco smoke, so the response of rat arteries to secondhand marijuana smoke is likely to reflect how human arteries might respond.”
The researchers were interested in seeing how blood vessels respond when exposed to secondhand smoke. In a process known as flow mediated dilation (FMD), arteries expand to make room for more blood when they detect more blood flow is needed for tissues. However, exposure to smoke impedes this process, which could put an individual at risk for numerous heart problems.
For the study, the rats were subjected to the same amount of smoke typically found in restaurants that permit smoking. Using a machine that simulated how a person puffs on a cigarette, the rats had a 50 percent drop in FMD after one minute of exposure. This reduction was identical to rats exposed to marijuana secondhand smoke.
The study also looked at the rolling paper used for marijuana cigarettes to determine if that was causing the cardiovascular effects. They burned cannabis that was not rolled and the results were the same, indicating that the paper had nothing to do with reduction in FMD.
Various studies in the past few years have shown secondhand tobacco smoke releases thousands of dangerous toxins into the air. As the use of cannabis for either recreational or medicinal purposes increases, researchers are now trying to understand any potential health issues associated with marijuana secondhand smoke.
“The biggest reason that people believe marijuana secondhand smoke is harmless is because the public health community hasn’t had direct evidence of its harmful effects like it does with tobacco,” Springer noted. “We hadn’t done the experiments, so I think there is definitely an underestimation of how harmful marijuana smoke is.”
As previously reported by The Inquisitr, a recent study found chemicals in the artificial smoke emitted by electronic cigarettes may cause cancer. Two ingredients in the e-liquid, propylene glycol and glycerin, give off toxic chemicals when warmed by the e-cigarette’s heating element.
According to Springer, more research is needed to identify the reason secondhand marijuana smoke affects the blood vessels for a longer period time than tobacco smoke.
“At this point, we’re saying that inhaling any smoke is detrimental to your health,” he said. “I think that people should avoid inhaling smoke whether it’s from tobacco or marijuana cigarettes, forest fires, barbecues— just avoid smoke.”
Studying the effects of marijuana secondhand smoke is difficult as the plant is labeled as an illegal substance by the federal government. The Food and Drug Administration, as well as the Drug Enforcement Agency, must grant approval before any cannabis study can begin.
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