The tar phase of marijuana smoke contains many of the same carcinogenic compounds found in tobacco smoke.
Smoking marijuana in combination with tobacco may be especially injurious to bronchial epithelium.
Both marijuana and tobacco smokers show evidence of abnormalities in cell nuclei and changes in genes known to have an early role in the development of lung cancer.
Even though marijuana smokers smoke less plant material, one joint yields up to three times the tar of one cigarette because joints are packed more loosely and don't have filters.
Marijuana smokers inhale more deeply, hold their breaths longer, and smoke the joint down to the last fraction of an inch, which delivers more irritating particles to the lungs.
Source: Barsky SH, Roth MD, Kleerup EC, et al. Histopathologic and molecular alterations in bronchial epithelium in habitual smokers of marijuana, cocaine, and/or tobacco. JNCI. 1998;90(16):1198-1205. |
