http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco study "Marijuana shown to be less damaging to lungs than tobacco" http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco http://www.ucsf.edu/news/2012/01/11282/ ... gs-tobacco "Marijuana shown to be less damaging to lungs than tobacco" "Marijuana shown to be less damaging to lungs than tobacco" "Marijuana shown to be less damaging to lungs than tobacco"