More than 2.7 billion people worldwide, including children, are exposed to secondhand smoke. This exposure caused an estimated 1.7 million deaths in 2023. The findings come from a study published Tuesday in the medical journal The Lancet.
The study says tobacco remains one of the world’s leading causes of disease. An estimated 8 million people died from smoking-related illness in 2023, including nonsmokers exposed to secondhand smoke.
The study says secondhand smoke is a globally recognized health risk, with no safe level of exposure to its fumes.
Researchers reviewed various studies and population-based surveys published in PubMed, the U.S. National Institutes of Health’s database, to estimate the number of people exposed to secondhand smoke and the resulting disease burden across 204 countries and territories worldwide from 1990 to 2023.
The study found that of the roughly 2.7 billion people exposed to secondhand smoke in 2023, 767 million were children aged 0 to 14.
Secondhand smoke caused an estimated 1.66 million premature deaths that year. Many others suffered premature illness and physical disability as a result. Among these conditions, ischemic heart disease was the most common — a condition that occurs when the heart muscle doesn’t receive enough oxygen.
According to the study’s calculations, secondhand smoke caused 5.2 million respiratory infections among children in 2023.
When someone smokes, people around them are exposed to two kinds of smoke. One is the smoke that comes directly from burning tobacco products. The other is the smoke exhaled by the smoker.
The study says nonsmokers are mostly exposed to the smoke coming directly from burning tobacco products. This smoke passes through no filter. As a result, it contains a higher concentration of toxic and carcinogenic substances than the smoke the smoker themselves inhales.
The global smoking rate has fallen significantly since 1990. However, because of population growth and a rise in the number of people exposed to secondhand smoke in Africa and the Middle East, the total number of people affected worldwide has remained nearly unchanged.
Women are comparatively more harmed by secondhand smoke. Particularly in regions where smoking rates among women are low, they are still being harmed by others’ smoking.
The study says that despite this enormous health risk, secondhand smoke is still rarely acknowledged as a major risk factor for women’s health.
To better protect women and children from secondhand smoke, the researchers have called on governments to take stricter measures to control tobacco use in public places and in homes.