Subscribe
Short-term exposure to landscape fire-sourced fine particulate matter (LFS PM2.5) is associated with increased hospital admissions for multiple diseases in children and adolescents, a study found.
LFS PM2.5 was associated with increased risks of all-cause, respiratory, infectious, cardiovascular, neurological, diabetes, cancer, and digestive hospital admissions among children. During 2000 to 2019, 67.9 million all-cause hospital admissions among children and adolescents aged 0-19 years were recorded.
The study published in Nature Communications on October 22, 2025, is the most comprehensive multi-country/territory study to data exploring the associations between LFS PM2.5 and child morbidity.
Landscape fires occur in natural (forests, grassland) and cultural (farmlands) landscapes and include both planned and unplanned fires such as anthropogenic fires and wildfires. LFS air pollution can travel thousands of kilometres, affecting larger populations and posing a greater public health risk.
The researchers led by Shuang Zhou from Monash University in Australia analysed daily hospital admission data from 1,012 communities in seven countries/territories (New South Wales (Australia), Brazil, Canada, Chile, New Zealand, Taiwan, and Thailand), linked to a high-resolution LFS PM2.5 dataset.
The study emphasised the acute vulnerabilities in pediatric populations, connecting episodic exposures to spikes in healthcare visits for cause-specific illnesses.
The exposure-response relationships varied across different diseases. Risks for respiratory, infectious, and neurological conditions increased even at low exposure, while others rose only above 15-20 μg/m3 (microgram per cubic metre).
“Each 10 μg/m3 increase in LFS PM2.5 was associated with elevated risks for all-cause (1.1%), respiratory (1.9%), infectious (1.5%), cardiovascular (2.9%), neurological (2.8%), diabetes (3.7%), cancer (1.5%), and digestive (0.8%) hospital admissions,” the study found.
Geographical heterogeneity existed, and significant effect modifications by age, local GDP, and country income class were observed.
Communities in Brazil, Chile, and Thailand experienced higher LFS PM2.5 levels, compared with other regions. Chile recorded the highest LFS PM2.5 exposure, with a median concentration of 9.5 µg/m3, followed by Brazil (2.2 µg/m3) and Thailand (1.6 µg/m3).
Moderate levels were observed in Australia (1.1 µg/m3) and Taiwan (1.1 µg/m3), while New Zealand (0.7 µg/m3) had slightly lower levels. The lowest LFS PM2.5 concentrations were recorded in Canada (0.3 µg/m3).
Children aged 5-9 years showed higher risks for all-cause and infectious hospital admissions. Children in communities with a low or medium GDP per capita and upper-middle income countries showed higher risks of all-cause and digestive hospital admissions than those in communities with a high GDP per capita and high-income countries.
Children exhibit greater vulnerability to LFS PM2.5, possibly due to behaviours such as spending more time outdoors and the immaturity of their respiratory and immune systems. Globally, LFS PM2.5 contributed to an estimated 12.9 million deaths in children and adolescents during 2000-2014.
The study underscored the need for targeted interventions such as improving indoor air quality through air filtration systems, increasing public awareness through education programmes, and strengthening policies to mitigate the disproportionate burden of LFS PM2.5 in lower socioeconomic status regions.