Kolkata (PTI): When a person smokes, 15 per cent is inhaled and the remaining 85 per cent containing carbon monoxide, formaldehyde, ammonia, nitrosamines, benzopyrines and 4,000 chemicals injurious to the human body, exhaled, according to a study.

"WHO has emphasised that this passive smoking is no less dangerous than direct smoking. The total damages are indeed alarming, including cancer in various organs of the body," according to the study by the Indian Society on Tobacco and Health (Kolkata branch).

"India has the highest incidence of oral cancer and smoking increases risk of heart diseases, high blood pressure, lung problems, including smokers' cough, COPD and other respiratory diseases," it said.

The study said India's annual tobacco-related death was approximately 10 lakhs, 2,200 per day, 91 per hour and three every two minutes.

If the situation continued tobacco products would cause upto one billion deaths by the end of the 21st century, it said.

Passive smoking was particularly dangerous for women and children, who fell victim to chronic chest infection and asthma attack.

Children might also have retarded brain development and there could be sudden infant death syndrome, it said.