A study by the University of Monash, in Australia, reveals this Monday that only 0.18% of the planet’s land area and 0.001% of the global population were exposed in 2019 to levels of fine particles in the atmosphere below the latest safety levels recommended by the World Health Organization (WHO).
Fine particles, known as PM2.5, are suspended particles with a diameter of less than 2.5 micrometers. These particles, associated with the use of fossil fuelshave been linked to deaths caused by heart or lung disease and, according to the WHO, are one of the greatest environmental threats to human health, alongside the climate change. The most recent WHO air quality guidelines, published in 2021, recommend that the concentration of fine particles not exceed an annual average of five micrograms per m³ (cubic meter).
There is a lack of air pollution monitoring stations worldwide, which has resulted in gaps in data on local, national, regional and global exposure to fine particles. The study published in the scientific journal The Lancet Planetary Health brings an important map of how the concentration of PM2.5 has evolved in the last two decades throughout the world, seeking to draw global estimates of the daily concentrations of fine particles in the environment using artificial intelligence.
To more accurately assess global PM2.5 concentrations, the team led by researcher Yuming Guo, from the School of Public Health and Preventive Medicine at Monash University in Melbourne, Australia, turned to traditional observations of air quality monitoring. , satellite meteorological and atmospheric pollution detectors, statistical and machine learningthat is, artificial intelligence systems programmed to learn from data.
“In this study, we used an innovative approach to machine learning to integrate multiple meteorological and geological information to estimate global daily concentrations of PM2.5”, says the researcher, quoted in a statement. Thus, it was possible for the researchers to analyze the data between 2000 and 2019 at a high resolution, explains Yuming Guo.
uneven exposure
In 2019, on more than 70% of the days there were concentrations of PM2.5 above 15 micrograms per m³, which is considered the daily safe limit by the WHO. The team concluded, however, that there continues to be uneven exposure of the population to harmful concentrations of fine particles.
“Based on the new WHO 2021 guideline limit, only 0.18% of the global land area and 0.001% of the global population were exposed to an annual exposure below this guideline limit (annual average of 5 micrograms/m³) in 2019 “, says the press release about the study.
The highest concentrations of PM2.5 were distributed in the East Asia (50 micrograms per m³) and South Asia (37.2) regions, followed by North Africa (30.1). Australia and New Zealand (8.5 micrograms per m³), other regions of Oceania (12.6) and South America (15.6) had the lowest annual concentrations of fine particles.
These data are in line with data on air quality from the World Health Organization (WHO), which last year showed that 99% of the planet’s population breathes air with levels of pollution that exceed the limits considered acceptable. People living in low-income countries are the most exposed to fine particulate pollution and nitrogen dioxide, which endanger their health and cause premature mortality.
In 2020, air pollution caused the premature death of at least 238,000 people in the European Union, according to data from the European Environment Agency (EEA). In that year, in the EU, 96% of the population of cities was exposed to concentrations of PM2.5 fine particles higher than recommended.
In the European Union, the maximum permitted levels of PM2.5 particles in the air are 25 micrograms per m³, well above the WHO recommendation of just five micrograms per m³, set in 2021. A proposal from the European Commission for the revision of the Air Quality Directive launched the possibility of reducing – but only in 2030 – this annual limit by more than half, to 10 micrograms per m³.
In the United States, there is currently a proposal to revise the regulations of the Environmental Protection Agency (EPA) on this matter so that the maximum values of PM2.5 pass from the current 12 micrograms per m³ to a level between nine and ten micrograms per m³. m³.