Even Casual Smoking Can Lead to Lung Disease and Injury, Study Finds
Just having an occasional cigarette or two may lead to the same dangers as habitual smoking, a new study finds. Researchers at the Department of Genetic Medicine, Weill Cornell Medical College in New York have found that even low exposure to tobacco smoke can cause irreparable damage to lung cells that are essential to breathing function. Although it has been known for some time that smoking of any kind can cause health hazards, prior research has not quite evidenced whether there is any safe "threshold" of smoke exposure—including secondhand smoke, occasional smoking, and habit smoking.
For habit smokers trying to cut back, the new findings reveal that simply "tapering off" the amount of cigarettes smoked will not benefit the smoker in the long run. Light smoke exposure—including casual smoking and secondhand smoke—creates gradual reductions in lung function and a higher risk of lung disease than non-tobacco users.
For their study, researchers sought to identify the biological changes in individuals with low smoke exposure in comparison to non-exposed individuals. Lead researcher Dr. Ronald Crystal and colleagues assessed a sample of 121 participants, comprised of nonsmokers, low exposure users, and active smokers. The researchers used urine samples from the participants to measure their levels of nicotine exposure and determine to which group each individual belonged. Then, researchers examined the participants’ entire genome by collecting samples of small airway epithelium—the area of the lungs first adversely affected by smoking—from the participants via bronchoscopy. These samples would help establish to what degree the genes managing airway cells were being damaged among all the groups. As a result of their testing, researchers found that all levels of nicotine or cotinine exposure created genetic abnormalities in the participants’ genetic makeup. Because these cells are abnormally being turned on and off in response to nicotine, even at low exposure, the damaged biological functioning could eventually lead to the development of lung cancer or chronic obstructive pulmonary disease (COPD).
The study answers a very prevalent question among habitual and casual smokers alike: is there any safe amount of cigarette use? The answer is no. Even if the exposure seems minor, there is no threshold below which smoke inhalation becomes safe. Smoking cigarettes just once or twice a week or being exposed to secondhand smoke from a housemate, friend, or coworker on a regular basis can create lasting damages to the lungs.
According to the Center for Disease Control and Prevention (CDC), over 46 million American adults smoke cigarettes. Approximately 1,800 adults and 1,000 minors in the U.S. became daily smokers each day. Of course, compared to heavy cigarette smokers, casual smokers’ risks are not as immediate or severe. Yet with smoke exposure having grown so widespread, even low levels of exposure have caused concern among health officials. Each year, tobacco use causes 5 million deaths worldwide, with 443,000 occurring in the U.S. alone. Smoking remains the nation’s the leading cause of preventable death.
The researcher’s latest study was published in the August 20, 2010 issue of the American Journal of Respiratory and Critical Care Medicine.
Source: HealthDay News, Study Finds Even a Little Cigarette Smoke Harms Airway, August 20, 2010
