What Are the Effects of Secondhand Marijuana Smoke?

By

Kaitlin Miller

The health effects of secondhand marijuana smoke are hazy

Attitudes about marijuana across the country are changing, leading to more and more states legalizing marijuana for medical as well as recreational purposes. As marijuana use becomes more commonplace, you might be considering smoking marijuana or simply allowing others to smoke near you. But is the smoke actually safe to be around? This is particularly a concern for those with health conditions such as asthma as well as those with children or pets in their house. 

According to the Centers for Disease Control and Prevention, there are many unanswered questions about secondhand marijuana smoke exposure. There simply isn’t as much research into the effects of secondhand cannabis smoke as there is into that of secondhand tobacco smoke. Regardless, inhaling smoke of any kind, whether from burning wood, tobacco or marijuana, is bad for the lungs, heart and blood vessels.

Early studies on rats have shown potential negative effects of secondhand marijuana smoke on blood vessel function. While tobacco smoke has been proven to cause coronary heart disease, stroke and lung cancer, research has yet to find an increased risk of cancer or other health conditions associated with marijuana use.

While there isn’t conclusive evidence linking it to health issues, marijuana smoke isn’t harmless either. According to the National Institute on Drug Abuse, marijuana smoke contains more carcinogenic combustion products than cigarette smoke. And secondhand marijuana smoke contains similar, if not higher, amounts of many of the same toxins and carcinogens found in directly inhaled marijuana smoke, according to the American Lung Association.

Another big concern is that you can get a “contact high” from being around marijuana smoke. While marijuana’s mind-altering substance, THC, is exhaled back into the air through secondhand marijuana smoke, it’s in very small amounts. Contact highs have proven to be highly unlikely but possible in scientific studies. Only in extreme circumstances would someone inhaling secondhand marijuana smoke experience impairments or have high enough THC levels in their body to fail a drug test. 

“Contact high” might be a health myth, but the American Lung Association recommends avoiding exposure to secondhand marijuana smoke due to its potential risks. If you choose to smoke marijuana, it’s best to do so in ways that don’t impact the health of others. That means following proper etiquette and not smoking inside shared air spaces, including public places. If you are interested in trying marijuana, here is what you should know before shopping for it.