One of these should answer every question you have!

Cannabis Smoke and Cancer: Assessing the Risk
Cannabis Smoke and Cancer: Assessing the Risk - NORML

Cannabis and tobacco smoke are not equally carcinogenic
Cannabis and tobacco smoke are not equally carcinogenic

Smoking Marijuana Does Not Cause Lung Cancer
US: Web: Study: Smoking Marijuana Does Not Cause Lung Cancer

Tobacco and marijuana use on offspring growth from birth through 3 years of age.
The effects of prenatal tobacco and marijuana use ...[Neurotoxicol Teratol. 1992 Nov-Dec] - PubMed Result

Progression from marijuana use to daily smoking and nicotine dependence
Erowid.org: Erowid Reference 6951 : Progression from marijuana use to daily smoking and nicotine dependence in a national sample of U.S. adolescents : Timberlake DS, Haberstick BC, Hopfer CJ, Bricker J, Sakai JT, Lessem JM, Hewitt JK

High anxieties - What the WHO doesn't want you to know about cannabis
High anxieties - What the WHO doesn't want you to know about cannabis - 21 February 1998 - New Scientist

Radioactive tobacco
http://www.cannabisculture.com/news/tobacco/

Click the link in my sig for the PROTECTIVE roll of cannabis in lung cancer- it's under- CANCER- lung. Granny:hippy: