There Might Be Risks to Secondhand Weed Smoke

There might be risks to secondhand weed smoke after all.

Matthew Springer, a cardiology professor at the University of California, San Francisco, published research showing secondhand smoke makes it harder for rat arteries to expand and allow for healthy blood flow.

Springer decided to study the effects secondhand cannabis smoke has on non-smokers when he was at a Paul McCartney concert in San Francisco. He saw a bunch of people lighting up joints and thought about how San Franciscans would never tolerate that much cigarette smoke in public. So, he began to wonder whether cannabis smoke has the same toxic effects as cigarette smoke. Springer was already researching health effects of second hand tobacco smoke on rats at his lab at UCSF so he decided to run the same tests using cannabis.

The constructing effect of cannabis smoke on rat arteries is the same as tobacco smoke, but the rats that were exposed to cannabis smoke took 60 minutes longer to recover than the ones exposed to tobacco smoke. Springer says the study’s conclusion isn’t an anti-THC one, but an anti-smoke one, stating, “We in the public health community have been telling them for decades to avoid inhaling secondhand smoke from tobacco. We have not been telling them to avoid secondhand smoke from marijuana, and that’s not because it’s not bad for you — it’s because we just haven’t known. The experiments haven’t been done.”