Health, Australia (Commonwealth Union) – A recent report indicates that over one million deaths worldwide annually are linked to short-term exposure (lasting from hours to days) to fine particulate matter (PM2.5) in air pollution. Eastern Asia bears the brunt, with over 50 percent of global deaths attributed to short-term PM2.5.
The particulate matter can range in different: coarse particles (PM10) and fine particles (PM2.5). PM10 particles have a diameter of 10 micrometers or less, while PM2.5 particles have a diameter of 2.5 micrometers or less. These tiny particles can easily be inhaled and can accumulate in the respiratory system, causing various health issues.
Exposure to particulate matter has been linked to a range of adverse health effects, especially for vulnerable populations such as children, the elderly, and those with pre-existing respiratory or cardiovascular conditions. The exposure to PM has been known to cause irritation of the eyes, nose, and throat, coughing, sneezing, and difficulty breathing. Long-term exposure can lead to more severe health problems, including lung cancer, asthma, heart disease, and premature death.
Studies have also focused on how PM can be a significant threat to pregnant women, which can possible bring about ill effects prior to birth.
In Australia, the number of deaths attributed to short-term PM2.5 rose by 40 percent between 2000 and 2019.
Researchers for the report point out that most research has traditionally focused on the health impacts of residing in urban areas with consistently high pollution levels, neglecting the intermittent spikes in pollution that can affect smaller urban areas due to events like landscape fires and dust storms.
A study conducted by Monash University, examining mortality rates and PM2.5 pollution levels in over 13,000 cities and towns worldwide from 2000 to 2019, was recently published in The Lancet Planetary Health.
Led by Professor Yuming Guo, this study is significant as it is the first to explore short-term exposure on a global scale, rather than focusing solely on the long-term effects of sustained exposure experienced by urban residents in highly polluted cities.
The researchers discovered that even brief exposure to PM2.5, lasting from a few hours to a few days, leads to over one million premature deaths worldwide annually, with Asia and Africa being particularly affected. Approximately 22.74 percent of these deaths occur in urban areas.
Professor Guo emphasized that the short-term health impacts of air pollution exposure have been extensively documented. For instance, during the “Black Summer” of 2019–20, Australia experienced megafires that were estimated to have caused 429 premature deaths and 3,230 hospital admissions due to acute and persistent exposure to extremely high levels of bushfire-related air pollution.
“But this is the first study to map the global impacts of these short bursts of air pollution exposure.”
The researchers further indicated that due to the high population densities in urban areas, as well as with the high levels of air pollution, “understanding the mortality burden associated with short-term exposure toPM2.5 in such areas is crucial for mitigating the negative effects of air pollution on the urban population.”
The study reveals that Asia bears the greatest burden of global mortality resulting from short-term PM2.5 exposure, accounting for around 65.2 percent of total deaths. Following closely, Africa constitutes 17.0 percent, while Europe and the Americas contribute 12.1 percent and 5.6 percent, respectively. Oceania records the smallest proportion at just 0.1 percent.
The regions experiencing the highest mortality burden were densely populated and heavily polluted areas across eastern Asia, southern Asia, and western Africa. In eastern Asia particularly, the fraction of deaths attributable to short-term PM2.5 exposure exceeded the global average by more than 50 percent.
While most areas in Australia witnessed a slight decline in the number of deaths linked to air pollution,but there was a notable increase in the attributable death fraction from 0.54 percent in 2000 to 0.76 percent in 2019, surpassing other subregions. This rise could be linked to the growing occurrence and magnitude of extreme weather-induced air pollution events, such as the bushfires experienced in 2019.
To address the acute health impacts of air pollution, especially in areas most affected, the study proposes targeted interventions like air pollution warning systems and community evacuation plans. These measures aim to mitigate the health risks associated with transient exposure to high concentrations of PM2.5.
