Melbourne: A study that was released in The Lancet Planetary Health journal found that almost everyone in the world is exposed to unhealthy levels of small air pollution particles known as PM2.5.
Only 0.18 per cent of the world's land area and 0.001 per cent of its population, according to research from Monash University in Australia, are exposed to PM2.5 levels below the safety thresholds advised by the World Health Organization (WHO). PM2.5 is the world's leading environmental health risk factor.
While the daily PM2.5 levels have reduced in Europe and North America in the two decades to 2019, levels have increased in South Asia, Australia, New Zealand, Latin America and the Caribbean, with more than 70 per cent of days globally seeing levels above what is safe.
The team utilised traditional air quality monitoring observations, satellite-based meteorological and air pollution detectors, and statistical and machine learning methods to more accurately assess PM2.5 concentrations globally.
“The unsafe PM2.5 concentrations also show different seasonal patterns that included Northeast China and North India during their winter months (December, January, and February), whereas eastern areas in northern America had high PM2.5 in its summer months (June, July, and August),” he said.
The study found that despite a slight decrease in high PM2.5 exposed days globally, by 2019 more than 70 per cent of days still had PM2.5 concentrations higher than 15 μg/m3.
In southern Asia and eastern Asia, more than 90 per cent of days had daily PM2.5 concentrations higher than 15 μg/m3, the researchers said.
Globally, the annual average PM2.5 from 2000 to 2019 was 32.8 µg/m3, they said. The study found that the highest PM2.5 concentrations were distributed in the regions of Eastern Asia (50.0 µg/m3) and Southern Asia (37.2 µg/m3), followed by northern Africa (30.1 µg/m3).
Australia and New Zealand (8.5 μg/m3), other regions in Oceania (12.6 μg/m3), and southern America (15.6 μg/m3) had the lowest annual PM2.5 concentrations, the researchers added.
With PTI inputs