§Puff for puff, smoking marijuana is more dangerous than smoking cigarettes.  http://162.99.3.213/products/manuals/matrix/ppt/marijuana.ppt [4]

• 22.2 million (8.4%) people were current (past month) users of marijuana in 2014, making it the most used illicit drug.
• Marijuana use was most prevalent among people age 18 to 25 (with 19.6% using it in the past month).
• 7.4% of people aged 12 to 17 reported using marijuana.
• A higher percentage of males (10.9%) used marijuana in the past month than females (6%).