An estimated 2.71 billion people worldwide, including 767 million children under age 15, were exposed to second-hand smoke in 2023, and that exposure contributed to about 1.66 million deaths, according to a Global Burden of Disease Study 2023 analysis published in The Lancet Public Health on September 7, 2026.
According to the analysis, second-hand smoke exposure in 2023 accounted for 1.66 million deaths and 44.8 million disability-adjusted life-years globally. Ischemic heart disease was the leading contributor to second-hand-smoke-attributable disability, accounting for 12.0 million disability-adjusted life-years overall. Among children, lower respiratory infections predominated, with an estimated 5.16 million disability-adjusted life-years attributed to second-hand-smoke exposure in that age group.
The study estimates that women accounted for 1.49 billion of those exposed, with female individuals in some countries experiencing nearly 1.8 times the exposure prevalence of male individuals, according to the analysis. Age-standardized exposure prevalence was highest in Southeast Asia, East Asia, and Oceania, at about 48.4%.
According to the analysis, global age-standardized prevalence of second-hand-smoke exposure declined by 22.2% between 1990 and 2023, but the absolute number of people exposed has remained roughly stable because of population growth and increased exposure in sub-Saharan Africa (up 98.5%) and North Africa and the Middle East (up 72.1%) over that period.
According to a companion analysis reported alongside the study, only 79 countries as of 2024 have achieved the highest protection standards set by the World Health Organization’s tobacco-control framework — with all public places completely smoke-free or at least 90% of the population covered by legislation — and the proportion of the global population covered by comprehensive smoke-free legislation has risen from 3% in 2007 to 33% in 2024, now covering 2.6 billion people. Approximately 70% of the world’s population, however, is still not protected by comprehensive smoke-free laws. The study links second-hand-smoke exposure to health conditions including stroke, lower respiratory infections, chronic obstructive pulmonary disease, asthma, type 2 diabetes, and cancers of the trachea, lung, and breast.
