What's the effect of cannabis on lungs? 

Cannabis smoke contains many compounds that are carcinogenic and can alter the respiratory epithelium. Chronic cannabis smoking has been associated with aggravated chronic bronchitis symptoms, increased risk of bullous emphysema, and pneumothorax. It can also lead to a negative impact on lung function, including damage to the airways and a drop in FEV1. Cannabis smoking is common among young patients with lung cancer, potentially leading to a different lung cancer profile. However, the effects of cannabis smoke on lung health remain controversial due to the co-consumption of tobacco. The acute inhalation of cannabis smoke modulates the pulmonary immune response, with different effects based on the THC:CBD ratio. More research is needed to understand the impact of cannabis inhalation on the pulmonary immune system and the potential consequences on lung health.

Marijuana and the Lung: Evolving Understandings.

The paper states that marijuana can cause bronchitis, but there is limited evidence to suggest that it causes distal airway/parenchymal lung disease, chronic obstructive pulmonary disease, or lung cancer.

Modulation of pulmonary immune function by inhaled cannabis products and consequences for lung disease

The paper discusses the potential consequences of inhaled cannabis on the pulmonary immune system, but does not provide a specific answer to the question about the effect of cannabis on lungs.

Differential inflammatory profile in the lungs of mice exposed to cannabis smoke with varying THC:CBD ratio

The paper discusses the acute effects of cannabis smoke on the lungs in mice. It shows that cannabis smoke exposure modulates the pulmonary immune response and increases lung inflammation. However, the specific effect of cannabis on lungs in humans is not mentioned in the paper.

[Inhaled marijuana and the lung, a toxic cocktail?]

The paper states that chronic cannabis smoking can lead to aggravated chronic bronchitis symptoms, increased risk of bullous emphysema and pneumothorax, negative impact on lung function, and potential association with undifferentiated lung cancer.

Cannabis inhalé et poumon, une liaison dangereuse ?

The paper states that the effects of cannabis smoke on the lungs are controversial, but chronic cannabis smokers may experience aggravated chronic bronchitis symptoms, increased risk of bullous emphysema, and negative impacts on lung function.