Tobacco continues to be the substance causing the maximum health damage globally. According to WHO estimates, there are around 1.1 thousand million smokers in the world, about one-third of the global population aged 15 and over. While consumption is levelling off and even decreasing in some countries, worldwide more people are smoking, and smokers are smoking more cigarettes. Substantially fewer cigarettes are smoked per day per smoker in developing countries than in developed countries. However, this gap is fast narrowing and unless effective tobacco control measures take place, daily cigarette consumption in developing countries is expected to increase as economic development results in increased real disposable income.
According to the World Health Report 2002, among industrialized countries where smoking has been common, smoking is estimated to cause over 90% of lung cancer in men and about 70% of lung cancer among women. In addition, in these countries, the attributable fractions are 56-80% for chronic respiratory disease and 22% for cardiovascular disease. Worldwide, it is estimated that tobacco causes about 8.8% of deaths (4.9 million) and 4.1% of DALYs (59.1 million). Unless current trends are not reversed, that figure is expected to rise to 10 million deaths per year by the 2020s or early 2030s, with 70% of those deaths occurring in developing countries.