Secondhand smoke continues to be responsible for approximately 1.7 million deaths annually across the globe, according to a major study published in The Lancet Public Health. The research, which assessed secondhand smoke as a global risk factor for the first time, found that while exposure has decreased in some nations, it remains a substantial driver of disease and premature death worldwide.
Researchers estimated that in 2023, 2.71 billion people were exposed to secondhand smoke, including 767 million children. The study combined data on exposure levels in homes and workplaces with established risks linking passive smoking to nine diseases, including heart disease, stroke, and lung cancer, to estimate the number of deaths that would not have occurred without this exposure.
Heart disease was identified as the leading cause of death linked to secondhand smoke, accounting for an estimated 537,000 deaths in 2023. Other significant causes included chronic obstructive pulmonary disease (COPD) with 354,000 deaths, stroke with 278,000, lower respiratory infections with 185,000, and lung, bronchial, and tracheal cancers with 161,000.
The highest burden of deaths was observed in South East Asia, East Asia, and Oceania, with around 689,000 deaths linked to secondhand smoke, followed by South Asia with approximately 428,000. The study highlighted that China, India, and Indonesia alone accounted for nearly half of all individuals exposed worldwide, reflecting persistently high smoking rates in these countries.
In contrast, the United Kingdom has seen considerable improvements. The number of estimated deaths from passive smoking fell from approximately 14,900 in 1990 to 6,100 in 2023. This decline is attributed to a reduction in adult smoking rates and increased public awareness. Despite this progress, the health burden persists, with an estimated 171,600 years of healthy life lost due to illness, disability, or premature death related to passive smoking in the UK in 2023.
The study's authors called for the implementation of stronger global tobacco control measures, including increased tobacco taxes, advertising bans, plain packaging, and improved access to smoking cessation programs. They also noted that the full impact of secondhand smoke may be underestimated, as exposure in locations like cars and hospitality venues, as well as the duration of exposure, were not fully captured in the study.