"Physical bodily injury was the leading cause of emergency department visits and hospitalizations among the cannabis users, with respiratory reasons coming in a close second," Vozoris said.

Marijuana smokers had higher blood and urine levels of several smoke-related toxins such as naphthalene, acrylamide and acrylonitrile than nonsmokers, a 2021 study found.

Naphthalene is associated with anemia, liver and neurological damage, while acrylamide and acrylonitrile have been associated with cancer and other health issues.

Another study done last year found teenagers were about twice as likely to report "wheezing or whistling" in the chest after vaping marijuana than after smoking cigarettes or using e-cigarettes.

Growing body of research

A number of studies have shown an association between marijuana use and injury, both physical and mental.

Heavy use of marijuana by teens and young adults with mood disorders -- such as depression and bipolar disorder -- has been linked to an increased risk of self-harm, suicide attempts and death, according to a 2021 study.

Another 2021 study found habitual users of cannabis, including teenagers, are increasingly showing up in emergency rooms complaining of severe intestinal distress that's known as "cannabis hyperemesis syndrome," or CHS.

The condition causes nausea, severe abdominal pain and prolonged vomiting "which can go on for hours," Dr.

Sam Wang, a pediatric emergency medicine specialist and toxicologist at Children's Hospital Colorado, told CNN in a prior interview.

A review published earlier this year looked at studies on over 43,000 people and found a negative impact of tetrahydrocannabinol or THC, the main psychoactive compound in cannabis, on the brain's higher levels of thinking.

For youth, this impact may "consequently lead to reduced educational attainment, and, in adults, to poor work performance and dangerous driving.