People who only smoked marijuana had higher blood and urine levels of several smoke-related toxins such as naphthalene, acrylamide and acrylonitrile than nonsmokers, according to the study published Monday in the journal EClinicalMedicine.
“Marijuana use is on the rise in the United States with a growing number of states legalizing it for medical and nonmedical purposes – including five additional states in the 2020 election,” said senior author Dr. Dana Gabuzda, a principal investigator in cancer immunology and virology at the Dana-Farber Cancer Institute in Boston, in a statement.
“The increase has renewed concerns about the potential health effects of marijuana smoke, which is known to contain some of the same toxic combustion products found in tobacco smoke,” Gabuzda said.
The new research presented data from three studies of 245 HIV-positive and HIV-negative participants. Researchers said they chose to study people with HIV infection because of the high prevalence of tobacco and marijuana smoking typically found in this population.
Medical records were compared to blood and urine samples of various chemicals produced by the breakdown of nicotine or the combustion of tobacco or marijuana.
Marijuana smokers, however, did not have higher levels of acrolein in their bodies.
“This is the first study to compare exposure to acrolein and other harmful smoke-related chemicals over time in exclusive marijuana smokers and tobacco smokers, and to see if those exposures are related to cardiovascular disease,” Gabuzda said.
Acrolein is a chemical with a burnt, sweet, pungent odor created by the burning of fuels such as gasoline or oil and organic matter such as tobacco. The chemical is not added to cigarettes; acrolein is produced by the burning of sugars present in tobacco when smoked.
While weed smokers had higher amounts of naphthalene, acrylamide and acrylonitrile in blood and urine than nonsmokers, even higher levels were found in people who smoked tobacco or a combination of marijuana and tobacco.
Acrylamide is a chemical used to make paper, plastics and dyes, but is also produced when vegetables such as potatoes are heated to high temperatures. It is also a component of tobacco smoke.
The EPA classifies acrylonitrile as a “probable human carcinogen.”