A first-of-its-kind study analyzing the rise in global landscape fire pollution over two decades has found that more than 2 billion people experience health-related environmental risks at least one day a year, with this number rising by 6.8% over the past decade. The study found increased exposure to fire, especially in low-income countries, and highlighted the widespread health impacts of fire pollution.
Recent increases in landscape fires due to climate change in countries such as Canada have highlighted the importance of this research and underscored the need for robust monitoring and prevention strategies.
Research shows that 2 billion people have experienced wildfire smoke on at least one day that can affect their health.
The world's first study to examine the global increase in landscape fire pollution over the past two decades has found that more than 2 billion people are exposed to environmental hazards that affect their health on at least one day each year. This number has increased by 6.8% over the past decade.
Research highlights the severity and scope of pollution caused by landscape fires and the serious impact on global populations, resulting in increased public health risks.
Air pollution from fires can have many adverse health effects, such as increased mortality and morbidity, and worsening of cardiorespiratory health and mental health globally.
The study, led by Australian researchers and published in the journal Nature, assessed daily global air pollution caused by fires between 2000 and 2019.
The study found that 2.18 billion people experience severe landscape fire air pollution on at least one day each year.
On average, each person globally is exposed to this pollution 9.9 days per year, rising by 2.1% over the past decade. Notably, exposure levels in low-income countries are approximately four times higher than in rich countries.
The study, led by Professor Yuming Guo and Professor Shanshan Li from the School of Population Health and Preventive Medicine at Monash University, also found that PM2.5 exposure levels were particularly high in Central Africa, Southeast Asia, South America and Siberia.
The study also looked at global production of ozone from landscape fires, an important fire-related pollutant that has so far been estimated only for the United States.
For the purpose of this study, landscape fire refers to any fire burning in natural and cultural landscapes (e.g., natural forests and plantations, shrubs, grasslands, pastures, farmland, and peri-urban areas), including planned or controlled fires (e.g., prescribed burns, agricultural fires) and wildfires (defined as uncontrolled or unplanned fires burning in wild vegetation).
A comprehensive assessment of global population exposure to fire-induced PM2.5 and ozone during 2000-2019 was calculated using machine learning methods with input data from chemical transport models, ground monitoring stations and gridded meteorological data.
Recently, pollution from wildfires in Canada spread smoke across North America, highlighting the increased severity and frequency of landscape fires due to climate change.
According to Professor Guo, no study to date has examined the long-term effects of the global increase in landscape fires, which often affect remote areas with few or no air quality monitoring stations. Furthermore, in many low-income countries there are no air quality monitoring stations even in urban areas.
"Air pollution from wildfire smoke travels hundreds, and sometimes thousands, of kilometers across hundreds and sometimes thousands of kilometers, affecting larger populations and posing greater public health risks," he said. "Mapping and tracking population exposure to air pollution from wildfires is critical to monitoring and managing their health impacts, implementing targeted prevention and intervention measures, and strengthening the case for climate change mitigation."