Jeanette M. Tetrault, MD, Clinical Epidemiologist at the Connecticut Department of Veterans Affairs, et al., stated in the article "Effects of Marijuana Smoking on Pulmonary Function and Respiratory Complications: A Systematic Review," published in the Feb. 12, 2007 issue of Archives of Internal Medicine:

“Conclusions: Short-term exposure to marijuana is associated with bronchodilation [opening of the air passages]. Physiologic data were inconclusive regarding an association between long-term marijuana smoking and airflow obstruction measures. Long-term marijuana smoking is associated with increased respiratory symptoms suggestive of obstructive lung disease.”

Feb. 12, 2007