Air pollution factors: expert opinion
2025-02-17 12:00:00 / News
According to the expert, the process of desertification continues in countries located in the central part of the Earth — from North Africa to China, as shown on the map. This contributes to an increase in the concentration of dust in the atmosphere.
Fact!
PM2.5 refers to small particles up to 2.5 micrometers in diameter (30 times smaller than the thickness of a human hair), which are formed when solid particles combine with water vapor. PM (Particulate Matter) refers to "suspended particles." In addition to PM2.5, there are other fractions: PM1, PM10, and PM100, which vary in size. Studying and monitoring these particles allows for the assessment of air pollution levels.
WHO and national standards
According to E. Abdulakhatov, the World Health Organization (WHO) recommends maximum permissible concentrations of PM2.5 at 5 micrograms/m3 per year and 15 micrograms/m3 per day. However, no country in the world has adopted these norms as national standards. "Air Quality Index" platform is used primarily in scientific research but is not considered a sufficient basis for developing government standards. The WHO guideline of 5 micrograms/m3 is typically used for city ratings.
"Tashkent Air Quality Monitoring" platform
In 2024, based on research by specialists from the Ministry of Ecology, Environmental Protection and Climate Change, Hydrometeorological Service Agency and the Committee for Sanitary and Epidemiological Well-Being, national standards for Uzbekistan were developed. According to these standards, the air pollution rate is set at 35 micrograms/m3 per year and 60 micrograms/m3 per day.
"For comparison, no country in the world has standards equal to those of the WHO. Even the countries of the European Union have developed their own national standards. In 2023-2024, the Ministry of Ecology, together with the Tashkent Khokimiyat, launched the "Tashkent Air Quality Monitoring" platform, where data is updated hourly, providing a reliable source of information," says the climatologist.
Effect of wind on air pollution
The expert noted that there is a concept known as the "wind rose" in the issue of air pollution, which reflects the influence of wind on the distribution of pollutants in the atmosphere. In coastal countries, where strong winds blow all year round, dust particles do not linger in the air.
In Tashkent, during the 1950s and 1980s, the wind predominantly blew from the northeast, creating a steady air circulation pattern known as the "wind rose." However, in the 1990s and 2020s, this pattern changed: due to the influx of new wind currents and the weakening of overall wind intensity, the city became a zone where dust particles accumulate.
"In the last century, the average wind speed in Tashkent was 1.7 m/s. From 1981 to 2010, it decreased to 1.4 m/s, and over the past five years, it has fallen to 1.3 m/s. The mountainous terrain surrounding the city also makes it difficult for air masses to move and the chaotic construction of high-rise buildings further impedes natural ventilation. As a result, dust accumulates, contributing to the deterioration of air quality," explained E. Abdulakhatov.
When we talk about greenery, we usually think of trees. However, landscaping includes not only trees but also lawns and mixed shrubs.
"From 2016 to 2023, the built-up area doubled, which led to a halving of green spaces. In particular, there are significantly fewer lawns compared to trees," the expert noted.
"Island of Warmth"
Erkin Abdulakhatov also discussed the concept of the "Island of Warmth."
"Since 2016, temperatures have been rising in Tashkent, especially in areas with active construction and a lack of green spaces. Hence, the concept of "heat islands" in Tashkent," said the specialist.
The climatologist also noted that harmful emissions from motor vehicles, as well as from heavy and light industrial enterprises, negatively impact the atmosphere of Tashkent.
For Reference: Information about permanent and seasonal factors of atmospheric air pollution was provided earlier.