Involuntary exposure to tobacco smoke is estimated to cause 1.66 million premature deaths each year worldwide. A study published on September 7, 2026, in The Lancet Public Health, covering 204 countries and territories and data from 1990 to 2023, estimates that 2.7 billion people are exposed to secondhand smoke. The researchers conclude especially that there is no level of exposure that can be considered safe, even when the amounts of smoke inhaled are low.
The health burden is considerable: in 2023, secondhand smoke is estimated to have caused the loss of 44.8 million disability-adjusted life years, an indicator combining premature mortality and years lived with disability. Among the main associated diseases are cardiovascular diseases, strokes, lung cancer, and chronic respiratory diseases. Ischemic heart disease alone accounts for about 12 million healthy life years lost.
767 Million Children Exposed to Smoke
Children are among the most vulnerable populations, with approximately 767 million minors exposed worldwide. The study attributes 5.16 million lower respiratory infections in children to secondhand smoke. Their developing bodies and respiratory characteristics make them particularly sensitive to substances present in smoke. Women are also more exposed than men, with a global prevalence estimated at 37.3% and 30.6%, respectively.
Reducing this exposure remains a major public health challenge. In 2024, only 79 countries had achieved the highest level of protection against tobacco smoke in public places. Researchers and health professionals emphasize the need to completely avoid exposure, especially in homes with children, and to expand smoke-free areas. The study’s results reinforce the finding that even limited exposure to secondhand smoke carries health risks.
