Evidence of health threat from chemicals in marijuana and tobacco smoke

Scientists at Dana-Farber Cancer Institute and the Centers for Disease Control and Prevention have uncovered new evidence of the potential health risks of chemicals in tobacco and marijuana smoke.

In a study published online by EClinicalMedicine, the researchers report that people who smoked only marijuana had several smoke-related toxic chemicals in their blood and urine, but at lower levels than those who smoked both tobacco and marijuana or tobacco only. Two of those chemicals, acrylonitrile and acrylamide, are known to be toxic at high levels. The investigators also found that exposure to acrolein, a chemical produced by the combustion of a variety of materials, increases with tobacco smoking but not marijuana smoking and contributes to cardiovascular disease in tobacco smokers.

The findings suggest that high acrolein levels may be a sign of increased risk of cardiovascular disease and that reducing exposure to the chemical could lower that risk. This is particularly important for people infected with HIV, the virus that causes AIDS, given high rates of tobacco smoking and the increased risk of heart disease in this group.