Second-hand Smoke caused 1.66 million deaths among non-smokers in 2023

Exposure to second-hand smoke (SHS) remains a major public health challenge. A new study published in The Lancet Public Health estimates that second-hand smoke exposure was responsible for 1.66 million deaths among non-smokers and 44.8 million disability-adjusted life years (DALYs) worldwide in 2023. The findings also show that women and children continue to bear a disproportionate share of this preventable health burden.

The study, led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington and published as part of the Global Burden of Disease Study 2023, provides the first dedicated assessment of second-hand smoke exposure and its attributable disease burden across 204 countries and territories between 1990 and 2023.

More than 2.7 billion people exposed worldwide 

Researchers estimate that 2.71 billion people were exposed to second-hand smoke in 2023. Among them were 1.49 billion women and 767 million children aged 0–14 years, highlighting the significant impact of involuntary tobacco smoke exposure on vulnerable populations.

The highest levels of exposure were reported in Southeast Asia, East Asia and Oceania, where the age-standardised prevalence reached 48.4%. China, India and Indonesia alone accounted for nearly half of all people exposed globally. 

Major health impacts across multiple diseases

The study assessed nine health outcomes linked to second-hand smoke exposure: ischaemic heart disease, stroke, chronic obstructive pulmonary disease (COPD), lower respiratory infections, lung cancer, breast cancer, type 2 diabetes, otitis media and asthma. Asthma was included for the first time as a health outcome attributable to second-hand smoke within the Global Burden of Disease framework.

Globally, ischaemic heart disease was the leading contributor to SHS-attributable DALYs, accounting for approximately 12 million DALYs. Among children, lower respiratory infections represented the largest share of the burden, contributing more than 5 million DALYs.

The findings reinforce the evidence that there is no safe level of exposure to second-hand smoke and highlight its role as a major contributor to cardiovascular, respiratory, metabolic and cancer-related diseases.

To read the full study, click here: 
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(26)00168-4/fulltext