Tobacco use fell by 2.5 percent worldwide a decade after the first global health treaty went into effect, World Health Organisation researchers said Wednesday. Smoking rates declined most sharply when countries implemented several of the measures called for in the 2005 pact, and rose in some nations that failed to do so, suggesting anti-tobacco policies make a real difference, they reported in The Lancet, a medical journal. The WHO Framework Convention on Tobacco Control’s 180 signatories agreed to introduce or boost tobacco taxes, smoke-free zones, warning labels, advertising bans, and programmes to help people kick the nicotine habit. The study, based on data from 126 nations, showed that the treaty “has been a success in reducing tobacco use in countries that engaged in strong implementation,” said co-author Geoffrey Fong, a professor at the University of Waterloo. Tobacco consumption is the single greatest preventable cause of death in the world, claiming nearly six million lives annually. Smoking also racks up more than a trillion dollars annually in health care and lost productivity costs. On average, smoking rates across the 126 nations dropped from 24.7 to 22.2 per cent over the decade examined. But trends varied widely across regions: smoking decreased in 90 countries, stayed the same in 12, and increased in 24. In northern Europe and South America -- where governments put in place many of the anti-tobacco measures -- smoking rates fell by 7.1 and 6.8 per cent, respectively, between 2005 to 2015. Africa, meanwhile, saw increases over the same period: 3.4 per cent in western Africa, 12.6 per cent in central Africa, and 4.6 per cent in the northern part of the continent. Application of the treaty measures was lax to non-existent in most of these regions. Tobacco taxes work best The findings “give tobacco activists an empirical argument with which to prod their governments into living up to their treaty obligations,” said Kenneth Warner, a professor at the University of Michigan’s School of Public Health. Early research leaves little doubt that higher taxation is most effective in discouraging smokers, especially in low- and middle-income countries. Agencies