(Okanlami) Fellow, Department of Anesthesiology and Critical Care Medicine.
(Fryer) Assistant Professor, Department of Environmental Health Sciences, School of Hygiene and Public Health.
(Hirshman) Professor, Departments of Anesthesiology, Environmental Health Sciences, and Medicine.
Received from the Departments of Anesthesiology and Environmental Health Sciences, The Johns Hopkins University, Baltimore, Maryland. Submitted for publication April 6, 1995. Accepted for publication September 29, 1995. Supported by National Institutes of Health grants HL-44727 and HL-10342 and by grants from the Council for Tobacco Research and the American Thoracic Society.
Address reprint requests to Dr. Hirshman: The Johns Hopkins School of Hygiene and Public Health, Division of Physiology/Room 7006, 615 North Wolfe Street, Baltimore, Maryland 21205.