Alarming results from world first study of two decades of global smoke pollution
The world’s first study of the increase in pollution from landscape fires across the globe over the past two decades reveals that over 2 billion people are exposed to at least one day of potentially health-impacting environmental hazard annually – a figure that has increased by 6.8 per cent in the last ten years.
The study highlights the severity and scale of the landscape fire-sourced air pollution, its increased impact on the world’s population and associated rise in public health risk. Exposure to fire-sourced air pollution has many adverse health impacts, including increased mortality and morbidity and a global worsening of cardiorespiratory conditions and mental health.
The study, which graced the cover of prestigious journal Nature, estimated the global daily air pollution from all fires from 2000 to 2019 – finding that 2.18 billion people were exposed to at least one day of substantial landscape fire air pollution in each year, with each person in the world having on average 9.9 days of exposure per year, an increase of 2.1 per cent in the last decade. It also found that exposure levels in low-income countries were about four-fold higher than in high income countries.
Led by Professors Yuming Guo and Associate Professor Shanshan Li, from Monash University’s School of Public Health and Preventive Medicine, the study also found that the exposure levels of PM2.5 were particularly high in Central Africa, Southeast Asia, South America and Siberia. The study also looked at global landscape fire-sourced ozone, an important fire-related pollutant that has only been estimated for the United States.
In the study, landscape fires refer to any fires burning in natural and cultural landscapes, e.g. natural and planted forest, shrub, grass, pastures, agricultural lands and peri-urban areas, including both planned or controlled fires (e.g., prescribed burns, agricultural fires) and wildfires (defined as uncontrolled or unplanned fires burning in wildland vegetation).
The comprehensive assessment of the global population's exposures to fire-sourced PM2.5 and ozone during 2000-2019 was calculated using a machine learning approach with inputs from chemical transport models, ground-based monitoring stations, and gridded weather data.
The recent pollution from the Canadian wildfires that spread smoke across North America highlighted the increase in severity and frequency of landscape fires due to climate change. According to Professor Guo, no study to date has looked at the long-range effect of this increase in landscape fires globally and wildfires often impact remote areas where there are few or no air quality monitoring stations. In addition, in many low-income countries, there are no air quality monitoring stations even in urban areas.
“The exposure to air pollution caused by landscape fire smoke travelling hundreds and sometimes even thousands of kilometres can affect much larger populations, and cause much larger public health risks,” he said.
“Mapping and tracking the population exposure to landscape fire-sourced air pollution are essential for monitoring and managing its health impacts, implementing targeted prevention and interventions, and strengthening arguments for mitigation of climate change.”
https://www.nature.com/articles/s41586-023-06398-6
About Monash University
Monash University is Australia’s largest university with more than 80,000 students. In the 60 years since its foundation, it has developed a reputation for world-leading high-impact research, quality teaching, and inspiring innovation.
With four campuses in Australia and a presence in Malaysia, China, India, Indonesia and Italy, it is one of the most internationalised Australian universities.
As a leading international medical research university with the largest medical faculty in Australia and integration with leading Australian teaching hospitals, we consistently rank in the top 50 universities worldwide for clinical, pre-clinical and health sciences.
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