Catching smoke: the rising and unequal burden of landscape fires on global health

3 They used previously published estimates of smoke-specific fine particulate matter (PM 2·5) and ozone (O 3) from global satellite-based fire emissions inventories and atmospheric modelling simulations that were calibrated to ground-based monitoring stations. 2 The authors estimated short-term impacts on mortality by linking smoke pollution to mortality counts from 2267 communities in 59 countries or territories around the world, consistent with previously published estimates. 4,5 In parallel, they estimated the effects of long-term exposure to smoke pollution using meta-analyses of cohort studies (based on all-source PM 2·5 and O 3). Based on these estimates, smoke pollution would rank as one of the leading drivers of global mortality, 6 and such a pattern is expected to increase, especially in areas that already bear the highest burden. 7 Xu and colleagues found that low-income and middle-income countries dominated the mortality burden, particularly countries in sub-Saharan Africa and Asia, although the gap with higher-income countries narrowed over the study period. 3 The drivers of long-term mortality trends varied by country, depending on underlying population characteristics and changes in smoke pollution exposure. [...]Xu and colleagues used a population-weighted country average that does not capture within-country variation in smoke pollution, despite significant regional variations in exposure. 3 In the USA, for example, the highest burden of smoke pollution exposure and health effects are in western regions affected by wildfires. 10 Finally, Xu and colleagues neither consider the individual contributions of different types of landscape fires (eg, wildfires, prescribed fires, bushfires, and agricultural burns) nor the synergistic effects among multiple smoke pollution components that could further aggravate the health burden.