USA. Latest scientific data indicates cannabis is safer than previously thought

New analysis of dangers posed by commonly used drugs has shown that cannabis is far safer than previously thought. Furthermore, alcohol may have been judged to be safer than it should have been. These are the finding from Scientific Reports, a division of Nature magazine.
The report shows that the most dangerous drugs, by a considerable margin, are Alcohol, Tobacco , Cocaine and Heroin. Safety is partly judged by the difference between a ‘safe’ recreational amount and levels considered to be dangerous. Cannabis, which has no recorded fatalities has no overdose potential. Whereas other drugs have a relatively narrow ‘safe’ usage level.
The full report is here http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311234/
and the simpler Washington Post review is here https://www.washingtonpost.com/news/wonk/wp/2015/02/23/marijuana-may-be-even-safer-than-previously-thought-researchers-say