Since Colorado became the first state to allow recreational marijuana use by adults, a new survey has found that marijuana consumption by Colorado high school students has dipped. There had been concern that the legalization would increase use by teens, but the biannual poll conducted by the Colorado Department of Public Health and Environment actually showed that pot use among high school students in Colorado was lower than the national average among teens. Washington, Alaska, and Oregon have also apporved recreational marijuana use in the past years, and six other states are considering similar proposals.