India: Bidi Smoking, Main Cause for Cancers: Study

Source from:  Malayala Manorama (in)  03/25/2013

Thiruvananthapuram: Smoking of bidis has registered a manifold increase in incidence of most prevalent cancers among men in Kerala, according to a study.

Separate studies on impact of bidi smoking on lung and oral cancers and cancers of larynx and hypo pharynx in men in the 30-84 age group in Karunagappally of Kollam district showed that bidi unfiltered tobacco flakes rolled in tendu leaf and tied with thread was among the most harmful smoking products.

The cohort study on bidi and lung cancer,covering 65,829 men, found bidi smokers had a 3.9-fold increase in lung cancer incidence compared to those who never smoked bidis.

Dr P Jayalekshmi of Regional Cancer Centre and principal author of the studies, said "Mainstream smoke of bidi has a much higher concentration of carcinogenic hydrocarbons. Bidi smokers also are found to take five puffs per minute compared to two by cigarettes in the same time. All these contribute to increasing the carcinogenic nature of bidi smoke."

The study found lung cancer risk among former bidi smokers higher than those never smoking it. Increasing number of bidis smoked and younger age of starting elevate lung cancer risk.

For quitters,it showed risk of lung cancer lower in former smokers. Lung cancer risk was found have a statistically significant decrease among those who stopped bidi smoking for 10 years or longer, compared to current bidi smokers.

The risk of cancers affecting the cheek (buccal) and lips (labial) showed a near four-fold increase in the study of 66,277 men. More daily consumption largely increased risk associated with gum and mouth cancers. Also tongue cancer risk significantly increased among men smoking for 30 years or longer and among men who started it at 18 years or younger.

Studies on cancer affecting the lower part of the throat, including voice box,laryngeal and hypo pharyngeal cancers,show those smoking bidis for more than 30 years have a higher risk of laryngeal cancers. Smokers who puff more than 15 bidis a day are at increased risk of hypo pharyngeal cancers.

On choosing Karunagappally as study location,Dr Jayalekshmi said "Karunagappally is known for its thorium containing monazite sand, causing high background radiation. We started the project in the late 1990s mainly to study the potential synergistic health effects of high background radiation and other factors including bidi smoking.

Figures with Regional Cancer Centre show 821 and 863 males registered as lung and oral cancer patients in 2011-12.Another 392 patients registered for care of hypo pharyngeal and laryngeal cancers during the period.

As many as 1.6 million males in Kerala smoke bidis,proven to contain higher levels of hazardous chemicals when compared to cigarettes, a release quoting the study report said.

The studies also reiterated the common knowledge that bidi smoking is more widespread among those with lower levels of education and family income. The Global Adult Tobacco Survey (GATS 2009-10) has it that 31.1 per cent of male bidi smokers in India have no formal schooling while 19.7 per cent are self employed. Bidi smokers in Kerala spend nearly Rs 140 monthly on this habit. Enditem