Cannabis smoking and dual use linked to higher respiratory risks

This longitudinal study examined respiratory health risks associated with cannabis consumption methods among 5,211 young adults (ages 18-24) with no prior respiratory conditions. Using data from the Population Assessment of Tobacco and Health Study collected between 2021-2023, researchers tracked individuals who reported cannabis vaping, smoking, or dual use at baseline and monitored them for the development of respiratory symptoms. The findings reveal a clear distinction between consumption methods: cannabis smoking alone increased respiratory symptom risk by 3 times, while the combination of smoking and vaping showed an even greater risk with 4.36 times higher odds of developing respiratory symptoms.

Notably, cannabis vaping alone did not show a statistically significant association with respiratory symptom onset, suggesting the inhalation of combustion byproducts from smoking—rather than vapor inhalation itself—may be the primary risk factor. However, the study revealed important nuances when tobacco use was excluded: dual cannabis vaping and smoking remained significantly associated with respiratory problems (aOR = 4.20), while cannabis smoking alone lost statistical significance. This suggests that the combination of repeated inhalation exposure, whether from tobacco co-use or cannabis polyuse, drives respiratory risk more than single-use methods.

The researchers emphasize these findings remain preliminary and highlight the need for more detailed data on specific cannabis products, consumption patterns, and frequency of use to better understand respiratory risks. While the study provides important public health information for young adults considering cannabis consumption methods, the absolute risk remains modest—only 2.3% of the study population developed new respiratory symptoms during the follow-up period. Understanding these patterns is crucial for harm reduction conversations, particularly as cannabis legalization expands and consumption methods diversify.