Secondhand smoke can trigger cravings among smokers. And now a study funded by the National Institute on Drug Abuse (NIDA) suggests even non-smokers get enough nicotine from secondhand smoke to raise their risk of nicotine addiction.
Researchers used positron emission tomography (PET) to show that one hour of secondhand smoke in an enclosed space results in enough nicotine reaching the brain to bind to receptors that are typically targeted by direct exposure to tobacco smoke. This happens in the brains of both smokers and non-smokers.
Prior research has demonstrated that secondhand smoke exposure increases the risk that children will begin smoking as teens and that it makes it more difficult for adult smokers to quit. These facts suggests that secondhand smoke acts on the brain in a way that would promote smoking behavior.
“These results show that even limited secondhand smoke exposure delivers enough nicotine to the brain to alter its function,” said NIDA Director Nora D. Volkow, M.D.
“Chronic or severe exposure could result in even higher brain nicotine levels, which may explain why secondhand smoke exposure increases vulnerability to nicotine addiction.”
“This study gives concrete evidence to support policies that ban smoking in public places, particularly enclosed spaces and around children,” said Arthur Brody, M.D., of the UCLA Department of Psychiatry & Biobehavioral Sciences and corresponding author for the article.
According to the Centers for Disease Control, almost 50,000 deaths per year can be attributed to secondhand smoke.
The study is published in Archives of General Psychiatry.
Source: National Institutes of Health