Marijuana smoke harms lungs in tobacco smokers, study finds | CNN

"If you're smoking an unfiltered joint, let's say, more particulates will reach the airways, get deposited and become irritants, which is why you see the mucus and the inflammation," she said. 

 In addition, tobacco smokers quickly exhale, while marijuana smokers often inhale and hold their breath to maximize the high, she said. 

 "People usually have a longer breath hold and a higher puff volume, so they are holding in the larger volume of smoke for a longer period of time," she said. "That could lead to micro-trauma of those airspaces. These are all questions for future research."…

https://www.cnn.com/2022/11/15/health/marijuana-lung-damage-study-wellness/index.html