UC Berkeley researchers found that secondhand bong smoke from cannabis may be just as dangerous as secondhand smoke from tobacco.

The study found that secondhand cannabis smoke in the home exposes nonsmokers to more particulate matter than wildfires and tobacco smoke, according to Smoke and Tobacco Free fellow and student researcher Patton Khuu Nguyen, who co-authored the study along with Sally Katharine Hammond.

“Cannabis bong smoking in the home generated several times greater particulate matter than tobacco cigarettes and hookah,” Nguyen said in an email.

Previous studies have measured such risks, but only in environments where researchers constrained the amount smoked.

This study, according to Nguyen, is the first to allow the participants to smoke to the extent of their own will, measuring the particles released from what they would smoke.

Within these conditions, researchers observed that cannabis smoking causes a significant risk to nonsmokers in the area.

“Secondhand cannabis smoke has the potential to cause significant disease, cannabis smoking should be included with cigarettes in clean indoor air policies,” Nguyen said in the email.

This information provides a new narrative for cannabis smoking for the 27% of young adults who believe exposure to secondhand cannabis smoke is safe, according to the study. Contrary to popular belief, the study suggests bong smoking is not safe.

Nguyen said that while the study was done in an unbiased manner, it has the potential to influence public policy and future research on cannabis smoking.

Specifically, Nguyen said that one of the other aspects of this study that supports further research on the risks of cannabis smoking is the increased public health risk of heart and lung diseases, including cancer.

“Our report and previous studies should guide efforts to educate the public on the potential adverse health effects of secondhand cannabis smoke on nonsmokers,” Nguyen said in the email.