“We know what cigarettes do to the lungs,” said study author Giselle Revah, M.D., a cardiothoracic radiologist and assistant professor at the University of Ottawa in Ottawa, Canada. “There are well researched and established findings of cigarette smoking on the lungs. Marijuana we know very little about.”

To find out more, Dr. Revah and colleagues compared chest CT results from 56 marijuana smokers with those of 57 non-smoking controls and 33 tobacco-only smokers.

Three-quarters of the marijuana smokers had emphysema, a lung disease that causes difficulty with breathing, compared with 67% of the tobacco-only smokers. Only 5% of the non-smokers had emphysema. Paraseptal emphysema, which damages the tiny ducts that connect to the air sacs in the lungs, was the predominant emphysema subtype in marijuana smokers compared to the tobacco-only group.

Radiological Society of North America. “Emphysema more common in marijuana smokers than cigarette smokers.” ScienceDaily. http://www.sciencedaily.com/releases/2022/11/221115113940.htm (originally accessed November 15, 2022).

Journal Reference

Luke Murtha, Paul Sathiadoss, Jean-Paul Salameh, Matthew D. F. Mcinnes, Giselle Revah. Chest CT Findings in Marijuana Smokers. Radiology, 2022; DOI: 10.1148/radiol.212611

The mean age of the MJ smokers in the study was 49.

The mean age of the tobacco smokers in the study was 60.