Cannabis
Cannabis contains more than 400 chemicals. The main psychoactive ingredient is delta-9-tetrahydrocannabinol, or 'THC'. Cannabis contains more tar than tobacco, and has a higher concentration of carcinogens (cancer-causing agents). Cannabis became a controlled substance in Britain in 1928 44% of 16 to 29 year-olds have tried cannabis at some point in their lives. Half of them have used it in the last year. In 1998, 76% of people arrested for drugs offences in Britain were charged with possession of cannabis. Smoking marijuana is more popular in America than surfing the Internet.