The figures, compiled by epidemiologists Majid Ezzati of Harvard School of Public Health and Alan Lopez of the University of Queensland, Australia, showed smoking caused the premature deaths of 4.83 million people in 2000.
Of the 4.83 million deaths, 2.41 million occurred in developing countries and 2.42 million in the industrialised world.
Cardiovascular disease was the biggest killer, accounting for the deaths of 1.69 million people. Following close behind, chronic obstructive pulmonary disease claimed some 970,000 lives while lung cancer killed 850,000.
“The health loss due to smoking will grow even larger unless effective interventions and policies that reduce smoking among men and prevent increases among women in developing countries are implemented,” the scientists warned in their study – which is to be published in the British medical weekly “The Lancet.”
Men smoke more
Men accounted for three-quarters of all the deaths, a figure rising to 84% in the developing nations where 930 million of the world's 1.1 billion smokers are to be found.
The news comes as the major tobacco companies, increasingly under siege in the industrialised world, focus on marketing their products to emerging nations with high population growth.
“Our findings mark the beginning of an era when the majority of smoking-caused deaths occur in developing countries," lead author Majid Ezzati of Harvard said.