Wildfire smoke is increasingly encroaching on urban and rural spaces throughout the world. Increasingly frequent wildfires in Siberia are projected to cause thousands of deaths and billions in costs for East Asia. Smoke temporarily covered all U.S. lakes between 2019 and 2021.
Researchers, however, know little about the global mortality burden related to smoke pollution. A new study published in The Lancet scientific journal sought to learn more about that burden.
Researchers found that 1.53 million deaths per year were attributable to wildfire-driven air pollution between 2000 and 2019, including 0.45 million deaths from cardiovascular issues and 0.22 million respiratory deaths. Particulate matter pollution contributed to 77.6% of deaths, while 22.4% of the deaths were attributed to surface ozone pollution.
Researchers calculated particulate matter and surface ozone from wildfires across 59 countries between 2000 and 2019 and obtained relative risks for both the short-term and long-term impact of exposures to particulate matter and surface ozone on cardiovascular and respiratory mortality. The data was obtained from previously published meta-analyses on particulate matter and surface ozone and from the Global Burden of Diseases Study 2019 published by the Institute for Health Metrics and Evaluation.
Over 90% of all attributable deaths were in low-income and middle-income regions. Sub-Saharan Africa had 606,769 deaths from wildfire smoke pollution, southeast Asia had 206,817 deaths, south Asia had 170,762 deaths, and east Asia had 147,291 deaths. The five countries with the largest death totals were China, the Democratic Republic of the Congo, India, Indonesia, and Nigeria.
Deaths attributed to cardiovascular issues saw an annual increase of 1.67% per year between 2000 and 2019, the study said. Deaths attributed to respiratory issues did not have statistically significant trends. In 2019, the attributable mortality rates in low-income countries remained four times higher than those in high-income countries, though this had reduced from nine times in 2000.
