Exposure to second-hand smoke has a direct impact on the brain and stimulates nicotine cravings among smokers, reveals study.
According to the study funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, exposure to this second-hand smoke evokes cravings among smokers.
The study used positron emission tomography (PET) to demonstrate that one hour of second-hand smoke in an enclosed space results in enough nicotine reaching the brain to bind receptors that are normally targeted by direct exposure to tobacco smoke. This happens in the brain of both smokers and non-smokers.
Previous research has shown that exposure to second-hand smoke increases the likelihood that children will become teenage smokers and makes it more difficult for adult smokers to quit.
Such associations suggest that second-hand smoke acts on the brain to promote smoking behaviour.
"These results show that even limited second-hand smoke exposure delivers enough nicotine to the brain to alter its function," NIDA Director Nora D. Volkow, M.D., said.
"Chronic or severe exposure could result in even higher brain nicotine levels, which may explain why second-hand smoke exposure increases vulnerability to nicotine addiction," she stated.
Arthur Brody, M.D., of the UCLA Department of Psychiatry and Biobehavioral Sciences and corresponding author for the article, said the study gives concrete evidence to support policies that ban smoking in public places, particularly enclosed spaces and around children.
The findings have been published in Archives of General Psychiatry.