More people in the U.S. are now smoking marijuana than cigarettes, according to a Gallup poll.

Cigarette use has been trending downward during the past decades, with only 11% of Americans saying they smoke them in a poll conducted July 5 to 26, compared to 45% in the mid-1950s.

Sixteen percent of Americans say they smoke marijuana, with 48% saying they have tried it at some point in their lives. In 1969, only 4% of Americans said they smoked marijuana.

Attitudes around both substances have also shifted dramatically.

In 2019, 83% of Americans said they thought cigarettes were "very harmful" to smokers, while 14% said they are "somewhat harmful." Nine out of 10 adults said in 2013 that smoking causes cancer, while 91% of smokers surveyed in 2015 said they wish they never started.

"Smoking cigarettes is clearly on the decline and is most likely to become even more of a rarity in the years ahead," Gallup Senior Scientist Dr. Frank Newport said. "This reflects both public awareness of its negative effects and continuing government efforts at all levels to curtail its use."

Meanwhile, 53% of people said in a July poll they think marijuana has positive effects on those who use it.

Still, alcohol is the most popular substance, and has remained consistent for a while. Sixty-seven percent of Americans in the most recent poll said they are drinkers, compared to 63% in 1939. About a third totally abstain from alcohol.