Second-hand smoke causes nearly 1.7M deaths globally: Study

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More than 2.7 billion people, including children, were exposed to secondhand smoke globally, contributing to nearly 1.7 million deaths in 2023, according to a study published Tuesday in The Lancet Public Health.

Tobacco remains a leading cause of disease globally, the study said, noting that many "non-smokers exposed to second-hand smoke" were among the estimated total of 8 million people who died in 2023 of smoking-related illnesses.

"Exposure to second-hand smoke is a globally recognized health risk, with no safe level of inhalation," it said.

By reviewing studies published in the U.S. National Institutes of Health database PubMed, along with population surveys, the study sought to estimate the prevalence of exposure to secondhand smoke and quantify the disease burden in 204 countries and territories between 1990 and 2023.

Among the approximately 2.7 billion people exposed to secondhand smoke in 2023 were 767 million children ages 0–14, the study found.

This exposure is estimated to have resulted in 1.66 million premature deaths, as well as premature disability and illness, led by ischemic heart disease, a condition caused by insufficient oxygen supply to the heart muscle.

In children, exposure to secondhand smoke is estimated to have caused 5.2 million respiratory tract infections in 2023, it said.

People near someone lighting up are exposed to both the "sidestream smoke" from the burning tobacco product and smoke exhaled by the active smoker, the study explained.

"The sidestream component, which dominates the air non-smokers breathe, is unfiltered ... carrying higher per-unit concentrations of the toxic and carcinogenic compounds" than the smoke inhaled by the active smoker, it said.

Despite significant declines in smoking prevalence globally since 1990, the absolute number of people exposed has remained stable because of population growth and increased exposure in Africa and the Middle East.

Women are also disproportionately affected by secondhand smoke, particularly in regions where smoking prevalence among women is low, it noted.

"Despite this substantial burden, (second-hand smoke) exposure remains rarely acknowledged as a major risk factor for female health," it said.

The study called for governments to implement stronger tobacco controls in public places and homes to better protect women and children from secondhand smoke.

Publication details

Luisa S Flor et al, Global, regional, and national prevalence of second-hand smoke and attributable disease burden in 204 countries and territories, 1990–2023: a systematic analysis for the Global Burden of Disease Study 2023, The Lancet Public Health (2026). DOI: 10.1016/s2468-2667(26)00168-4

Journal information: The Lancet Public Health

Key medical concepts

Mortality, PrematureMyocardial IschemiaRespiratory Tract Infections

Clinical categories

Common illnesses & PreventionPreventive medicinePulmonary medicineCardiologyChildren's healthWomen's health Who's behind this story?

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