Occasional smoking too damages the lungs--study

However, in what can be termed as a rude wake-up call for those who feel a drag now and then is harmless, a new study found that even low levels of smoke exposure can do significant damage to the lungs.

According to researchers, the effects of "casual" smoking on respiratory health may not be too damaging in the initial stages, but prolonged exposure to tobacco smoke could lead to chronic obstructive pulmonary disease (COPD) and even lung cancer.

Lead author of the study, Dr. Ronald Crystal, chief of the division of pulmonary and critical care medicine at Weill Cornell Medical College in New York City, stated, "There is no level of cigarette smoking or exposure to cigarette smoke that does not make the cells in your lungs sick. If you are an occasional smoker you are still at risk. Don't think that smoking one or two cigarettes a week means you are home free."

According to researchers, the effects of "casual" smoking on respiratory health may not be too damaging in the initial stages, but prolonged exposure to tobacco smoke could lead to chronic obstructive pulmonary disease (COPD) and even lung cancer.

Details of the study
In order to establish a biological link between second hand cigarette smoke and higher incidence of lung disease, the researchers recruited 121 healthy volunteers.

They tested the urine samples of the volunteers to measure the levels of nicotine and cotinine, markers of cigarette smoking within the body.

On the basis of this, the volunteers were categorized as nonsmokers, low-exposure smokers, or active smokers.

Next, their airway cells were examined for genetic activity using a bronchoscope.

The technique involved the removal of a small sample of cells lining the participants’ airway.

These are the epithelial cells that are the first to be affected by cigarette smoke and play an important role in diseases such as lung cancer.

The researchers then scanned each individual’s entire genome to differentiate between those who had direct exposure to nicotine smoke and those who had indirect exposure.

Revelations of the study
The investigators found that even extremely low levels of exposure to cigarette smoke produced genetic abnormalities in the cells of non smokers and occasional smokers.

Crystal stated, “Even at the lowest detectable levels of exposure, we found direct effects on the functioning of genes within the cells lining the airways.

“The genetic effect is much lower than those who are regular smokers, but this does not mean that there are no health consequences.

“Certain genes within the cells lining the airways are very sensitive to tobacco smoke, and changes in the function of these genes are the first evidence of 'biological disease' in the lungs or individuals.”

The study has been published in the American Journal of Respiratory and Critical Care Medicine.