A new study looking at daily ambient fine particulate matter (PM2.5) has found that only 0.001% of the world’s population is exposed to levels of air pollution considered safe by the WHO.
- According to the WHO, levels of daily ambient fine particles (PM2.5) in the air should not exceed 15 micrograms per cubic meter.
- Only 0.18% of the world’s land area and 0.001% of the world’s population are exposed to lower levels.
- Measuring less than one-fiftieth the width of a human hair, fine particles enter the bloodstream through the lungs and are the world’s leading environmental risk factor for disease.
Virtually no place on Earth is safe from harmful levels of air pollution, warns a new study published in the journal The Lancet Planetary Health.
Conducted by Monash University in Melbourne, Australia, this research looking at daily ambient fine particulate matter (PM2.5) around the world found that only 0.18% of the world’s land area and 0.001% of the world’s population are exposed to levels of PM2.5 below the safe levels recommended by the World Health Organization (WHO).
Air pollution: levels decreased in Europe but increased elsewhere
Remarkable fact: while daily levels decreased in Europe and North America during the two decades of study tracking (to 2019), they increased in South Asia, Australia, New Zealand , in Latin America and the Caribbean. Worldwide, for more than 70% of the time, levels were above what is considered safe.
The team of researchers, led by Professor Yuming Guo, looked at PM2.5 produced by diesel fumes, wood smoke, brake pads, tires and road dust. WHO guidelines state that these levels should not exceed 15 micrograms per cubic meter (μg/m³). Professor Guo and his team have mapped the changes in concentrations across the world over the past two decades.
To achieve this, they used traditional air quality monitoring methods, satellite-based air pollution meteorological detectors, as well as statistical and machine learning methods using artificial intelligence, to assess specifically PM2.5 concentrations globally. The study results fill an important gap in pollution research, due to the small number of air pollution monitoring stations around the world and the lack of information on local, national, resulting regional and global.
Health: fine particles are the main environmental risk factor
Measuring less than one-fiftieth the width of a human hair, the fine particles enter the bloodstream through the lungs, causing inflammation. They come mainly from road traffic and industry and are the main environmental risk factor for disease in the world.
“This work provides an in-depth understanding of the current state of outdoor air pollution and its impacts on human health. With this information, policy makers, public health officials and researchers can better assess the short and long term effects of air pollution on health and develop air pollution mitigation strategies”Professor Guo said in a communicated.
Fine particles: which regions of the world are the most polluted?
The highest concentrations were found in East Asia (50.0 µg/m3), South Asia (37.2 µg/m3) and North Africa (30.1 µg/m3). The study also identified alarming seasonal trends. For example, northeast China and northern India recorded dangerous levels during the winter months of December, January and February, while eastern regions of North America had the worst levels during the summer months, June, July and August. “We also recorded relatively high PM2.5 air pollution in August and September in South America and June to September in Sub-Saharan Africa”adds Yuming Guo.
Australia and New Zealand (8.5 μg/m³), other parts of Oceania (12.6) and South America (15.6) had the lowest annual air pollution concentrations . Recently, a study published in JAMA Network Open found that even PM2.5 exposures between 12.0 and 13.9 μg/m³ increased the risk of dying from cardiovascular disease by 16%.