Second-hand smoke kills over 880,000 people every year globally, and a quarter of those deaths are among children 14 years or younger. These sobering statistics have helped drive smoking bans in public places in many countries, but these bans still cover just 20% of the world’s population.
A new study led by Dr. Thomas Hone of Imperial College of London’s School of Public Health has strengthened the case for expanding of these measures by examining the effects of public smoking bans on infant and neonatal mortality in Brazil. The results have already caused a stir, with coverage in major Brazilian media outlets like Agência Brasil and Globo.
This research adds to Imperial’s track record of impacting public health debates in countries around the world – and now, students anywhere in the world can be a part of this high-profile work by enrolling in Imperial’s 100% online Global Masters of Public Health program.
Exposure to second-hand smoke can have significant, lasting health impacts on children. In the womb, second-hand smoke can negatively affect fetal development and increase risks of pre-term birth and low birth weight, and infant exposure can increase the risk of sudden infant death syndrome (SIDS), lower respiratory tract infections, and asthma.
Brazil has established itself as a leader in tobacco control internationally, beginning with a 1996 law implementing a partial smoking ban allowing smoking in separate and/or ventilated spaces, which helped reduce smoking prevalence from 34.8% in 1989 to 14.7% in 2013. A comprehensive federal ban took the next step in 2014 by completely prohibiting smoking in all enclosed public places, with no exceptions for separate smoking sections or ventilation (which is often ineffective in preventing second-hand smoke exposure).
Brazil is also a particularly interesting country to study because the national smoking ban was preceded by state-level activity, including 9 states introducing comprehensive smoking bans and 17 states strengthening partial smoking bans. This “natural experiment” helped researchers isolate the impacts of the different types of bans from 2000-2016 using a combination of municipal-level data and telephone surveys.
- Comprehensive bans were associated with a 5.2% reduction in infant mortality and a 3.4% reduction in neonatal mortality.
- Partial bans were associated with a 3.3% reduction in infant mortality, but no change in neonatal mortality.
Overall, strengthening smoking bans were estimated to have avoided over 15,000 infant deaths in Brazil, with the majority in the São Paulo and Rio de Janeiro owing both to their large populations and early implementation of comprehensive smoking bans. Notably, benefits were also greatest in municipalities with lower educational attainment and higher poverty rates, indicating significant equity benefits of these policies as well.
While this research was led by Imperial College of London’s Dr. Hone, the study was a truly international effort. Co-authors hailed from Brazil’s National Cancer Institute and Ministry of Health and the University of São Paulo, the University of Rotterdam in The Netherlands, the University of Edinburgh in Scotland, and the International Union Against Tuberculosis and Lung Disease.
This study was published on the World Health Organization’s World No Tobacco Day, and the goals of this research are similarly international. While the risks of second-hand smoke have led to comprehensive smoking bans in many high-income countries, lower- and middle-income countries (LMICs) have lagged behind – an issue that is often compounded by higher rates of smoking and second-hand smoke exposure.
With one-third of developing countries lagging behind the UN’s Sustainable Development Goal 2030 targets for neonatal mortality, this study of the impact of smoking bans in Brazil could thus be an important catalyst for progress in other LMIC contexts around the world. Public health students and professionals aspiring to make similar global impacts can join Imperial through the online Global Masters of Public Health degree.
