Does regular marijuana smoking cause COPD, Emphysema and/or Lung Cancer? In part 1, Donald Tashkin, MD examines risk of Chronic Obstructive Pulmonary Disease. Donald P. Tashkin, MD - Medical Director of the Pulmonary Function Laboratory, Professor of Medicine, University of California, Los Angeles. Presented to Fifth Clinical Conference on Cannabis Therapeutics held in Pacific Grove, CA, April, 2008. Conference hosted by Patients Out of Time.