More than 2.7 billion people, including children, were exposed to second-hand smoke worldwide, resulting in approximately 1.7 million deaths in 2023, according to a recently published study.
Tobacco remains a leading cause of disease worldwide, with the study noting that many “non-smokers exposed to second-hand smoke” were among the estimated eight million people who died in 2023 from smoking-related diseases.
The study added that “exposure to second-hand smoke is a globally recognised health risk, as there is no safe level of exposure”.
The research sought to estimate rates of exposure to second-hand smoke and determine the resulting disease burden across 204 countries and territories between 1990 and 2023. It reviewed studies indexed in the US National Institutes of Health’s PubMed database, alongside population-based surveys.
The study found that of the approximately 2.7 billion people exposed to second-hand smoke in 2023, 767 million were children aged between 0 and 14.
This exposure was estimated to have caused 1.66 million premature deaths, in addition to disability and ill health, with ischaemic heart disease ranking among the leading conditions. The disease occurs when the heart muscle does not receive an adequate supply of oxygen.
The study also found that exposure to second-hand smoke caused 5.2 million respiratory infections among children in 2023.
According to the study, people near someone who is smoking are exposed to both “sidestream smoke” emitted from the burning tobacco product and the smoke exhaled by the smoker.
It explained that “sidestream smoke”, which accounts for most of the air inhaled by non-smokers, is unfiltered and contains higher concentrations per unit of toxic and carcinogenic compounds than the smoke inhaled by smokers.
Despite a significant decline in global smoking prevalence since 1990, the absolute number of people exposed to tobacco smoke has remained largely unchanged due to population growth and rising exposure rates in Africa and the Middle East.
