Why does Tobacco and not Marijuana cause Cancer? Read this in-depth study to find out! User cyclist123, in the /r/trees - home of the ents subreddit, 12 Apr 2016
TIL that compounds in cannabis have been shown to kill various types of cancer cells (including lung cancer). User chchchcello, in the Today I Learned (TIL) subreddit, 28 May 2015
Cannabis and tobacco smoke are not equally carcinogenic User gnu_oldskool, in the Reddit Day Of subreddit, 26 Sep 2013
Good Guy Cannibis - Has four times more tar than tobacco products, but protects you against carcinogenic substances and prevents common cancers User Frogmjf, in the /r/trees - home of the ents subreddit, 27 Jun 2012