An estimated 2.71 billion people worldwide were exposed to second-hand smoke in 2023, contributing to 1.66 million deaths, according to new research. This includes 767 million children under the age of 15, described as especially vulnerable, along with 1.49 billion women. Second-hand smoke, also known as passive smoking, causes serious health harm, including heart disease, respiratory illness and cancer, and remains a leading cause of preventable deathworldwide.
Study scope and source
The findings come from the Global Burden of Disease (GBD) 2023 study, published in The Lancet Public Health, which estimated second-hand smoke exposure and health impacts across 204 countries and territories between 1990 and 2023.
Most of the world remains unprotected
Despite the scale of exposure, the study found that approximately 70% of the world's population is not protected by comprehensive smoke-free laws. As of 2024, only 79 countries — around 70% of them in the Americas — have achieved the highest protection standards under the World Health Organization framework, meaning either all public places are completely smoke-free or at least 90% of the population is covered by legislation.
The proportion of the global population covered by comprehensive smoke-free legislation rose from 3% in 2007 to 33% in 2024, now covering 2.6 billion people. The study's authors noted that while smoke-free policies directly reduce exposure, additional measures are needed, including tobacco taxation, marketing bans, plain packaging and cessation programmes.
Regional patterns
The researchers found that the total number of people affected by second-hand smoke exposure remained broadly stable globally, but rose sharply in sub-Saharan Africa, North Africa and the Middle East, which they attributed to population growth.
In the Central Europe, Eastern Europe and Central Asia region, exposure prevalence stood at 37.7%, higher than the global average of 33.9%, affecting 146 million people.
Most Western European countries fell within what researchers termed the "high-income super region," which showed some of the most significant progress in reducing passive smoking. Denmark and Norway recorded some of the world's largest reductions since 1990, at -48.8% and -44.3% respectively.
Health impact
Beyond the number of people exposed, the report found that second-hand smoke accounted for the loss of 44.8 million years of healthy life, continuing to be a major contributor to disability and premature death.
Researchers explained that while a smoker inhales "mainstream smoke" filtered through a cigarette, non-smokers primarily breathe in "sidestream smoke," which is unfiltered and contains higher concentrations of toxic and carcinogenic compounds than the smoke inhaled by the smoker.
The study found that second-hand smoke remains a substantial driver of global health loss, particularly through cardiovascular and paediatric respiratory diseases. Exposure to tobacco smoke was associated with several conditions, including stroke, lower respiratory infections, chronic obstructive pulmonary disease, asthma, type 2 diabetes, and cancers of the trachea, lung and breast.
Source: Euronews
