Study shows marijuana smoke exposure is not linked to higher risks of many tobacco-related harms
Cannabis smoking poses fewer pulmonary risks than tobacco smoking and it is not positively associated with the development of emphysema, according to medical imaging data published in the journal Current Problems in Diagnostic Radiology.
Harvard Medical School researchers compared chest CT scans of 285 subjects. Eighty-nine participants were non-smokers, 97 smoked tobacco, and 99 smoked marijuana.
Participants who smoked tobacco exhibited greater damage to their hearts and lungs than did those who exclusively smoked marijuana. Specifically, tobacco smokers were far more likely to demonstrate moderate to severe coronary artery calcifications and suffer from emphysema.
“The findings of our study collectively highlight the distinct patterns of pulmonary and cardiovascular manifestations associated with smoking and marijuana use,” the study’s authors concluded. “It appears that, in general, marijuana users do not appear to develop emphysema or pulmonary hyperinflation.”
Their conclusion is consistent with several other studies finding that cannabis smoke and tobacco smoke are not equally carcinogenic and that marijuana smoke exposure is not linked to higher risks of either COPD, emphysema, lung cancer, or other tobacco-related harms. Moreover, the use of vaporization technology, which heats herbal cannabis to a set temperature below the point of combustion, is associated with reduced exposure to toxic gasses and has been identified as a “safe and effective” cannabis delivery device in clinical trial settings.
Commenting on the findings, NORML’s Deputy Director Paul Armentano said: “Most Americans agree that tobacco smoking poses far greater harms to health than the use of cannabis. They’re right. Nonetheless, cannabis remains classified as a Schedule I controlled substance under federal law while tobacco, which is linked to hundreds of thousands of premature deaths annually, is federally descheduled. It makes no sense from either a public health standpoint or from a political standpoint to continue to treat marijuana as if it is more dangerous, or even equally as dangerous, as tobacco. The science is clear and consistent; it is not.”
This brief was reprinted from NORML. The abstract of the study, “Quantitative and qualitative imaging in marijuana users and smokers,” is available from ScienceDirect. Additional information is available from the NORML Fact Sheet, ‘Cannabis Exposure and Lung Health.‘
