Abstract
Cannabis use has become increasingly prevalent due to legalization and social acceptance, raising concerns about its potential health impacts, particularly on respiratory and oncological outcomes. Despite sharing toxic constituents with tobacco smoke, including polycyclic aromatic hydrocarbons and volatile organic compounds, the link between cannabis smoking and lung cancer remains inconclusive. Epidemiological studies present conflicting findings, with some suggesting increased risk among heavy users, particularly when combined with tobacco, while others find no significant association. Chronic cannabis smoking has been associated with respiratory symptoms such as cough, sputum production and wheezing, often resembling chronic bronchitis. These symptoms may resolve upon cessation, indicating inflammatory rather than structural damage. Unlike tobacco, cannabis smoking does not consistently induce emphysema but may cause airflow obstruction and increased lung volumes with heavy and prolonged use. Additionally, cannabis smoking impairs alveolar macrophage function, diminishing antimicrobial capabilities and potentially increasing susceptibility to respiratory infections. While cannabinoids such as Δ9-tetrahydrocannabinol and cannabidiol exhibit potential antineoplastic effects in experimental models, chronic inhalation of cannabis smoke may negate these benefits through exposure to carcinogenic byproducts and chronic inflammation. The concurrent use of tobacco and cannabis amplifies respiratory risks, suggesting a synergistic effect. Given the rise in cannabis consumption and potency trends, ongoing research is essential to clarify long-term respiratory and oncological impacts. Public health strategies should focus on harm reduction and promoting non-combustible methods of cannabis use, while healthcare providers should educate users about the potential risks associated with chronic smoking. Further longitudinal studies with standardized exposure metrics are necessary to resolve existing uncertainties and inform safer use practices.