States in the US that smoke the most marijuana also have the highest belief that the drug has no adverse health risks, a study has found.
The data was collected by the Substance Abuse and Mental Health Services Administration in the US between 2012 to 2014, among 204,000 people starting from the age of 12. The research found that around 20.3 million people, almost 8% of the US population, used marijuana in the last month alone.
The study also found that different states demonstrated variations in usage and perception.
The West and Northeast regions had the highest users of 9.7% and 8.4% respectively, while only 6.4% used in the South.
At 15.5%, San Francisco reported the highest number of smokers followed by Colorado, Alaska, Oregon and Washington. Southern Texas used the least at just below 4%, closely followed by Tennessee, Alabama, Louisiana, Oklahoma, Kansas, North Dakota, Iowa, Utah, and Pennsylvania.
Furthermore, when it came to user perception on whether the drug was adversely affecting health, the same southern states had the strongest belief of potential physical harm, while other regions did not associate marijuana usage to its effects on the body.
The study's mathematical statistician, Art Hughes, stated that the finding refers specifically to the risk of physical harms caused by smoking pot. "The perceived risk of harm is a strong predictor of marijuana use," he explained.
According to the National Institute on Drug Abuse, long term effects of marijuana use may impair brain development, reducing the ability to think, learn and memorise. Other physical effects may include breathing difficulties, increased heart rate and problems with child development during and after pregnancy.