Air pollution is not only insidious but also widespread and virtually no place on Earth is free from some degree of airborne particles, according to scientists.
A team of researchers, led by Prof. Yuming Guo of Monash University’s School of Public Health and Preventive Medicine came to this conclusion by mapping the changing levels of PM2.5 particles around the world since 2000 with the help of observations from monitoring air quality. satellite-based weather data and air pollution detectors.
They also used an innovative machine learning approach to integrate various meteorological and geological data to estimate the Daily concentrations of PM2.5 at surface level globally between 2000 and 2019.
Numbers that go up and down
While daily air pollution levels generally declined in Europe and North America over the two decades, levels increased in South Asia, Australia, New Zealand, Latin America and the Caribbean, the researchers found. In general, more than 70% of the days of the year around the world have levels above what is considered safe for health, with concentrations of PM2.5 greater than 15 μg/m³, they report.
“In South and East Asia, more than 90% of days had daily concentrations of PM 2.5 greater than 15 μg/m³”, say the scientists behind the to study. “Australia and New Zealand saw a sharp increase in the number of days with high concentrations of PM2.5 in 2019“.
At the same time, the annual average of PM2.5 between 2000 and 2019 was 32.8 µg/m 3 with the highest concentrations of PM2.5 distributed in the East Asian regions (50.0 µg/m 3 ) and South Asia (37.2 µg/m 3 ). 3 ), followed by North Africa (30.1 µg/m 3 ).
And worrying numbers about air pollution
This is cause for concern becauseonly 0.18% of the global land area and 0.001% of the global population were exposed to an annual exposure below this reference limit (annual average of 5 μg/m³) in 2019″say scientists.
These findings add to the evidence that air pollution has reached endemic proportions, which is a major concern as long-term exposure to relatively low levels of PM2.5 pollutants can cause or worsen a variety of diseases in people of all ages. Every year, millions of people die from conditions related to air pollution.
Air pollution levels can vary throughout the year in specific areas, which can influence seasonal health-related issues. In their study, Guo and his colleagues found that dangerous PM2.5 concentrations show different seasonal patterns, with northeast China and northern India experiencing the highest levels during the winter months of December through February. Meanwhile, in areas of eastern North America, especially high levels of PM2.5 tend to occur in the summer, from June to August.
These findings, Guo says, can help policymakers, public health officials and researchers assess the short- and long-term health effects of air pollution and develop air pollution mitigation strategies accordingly.