Bishkek takes the 14th place in air pollution ranking. Such data are provided by AirVisual project website.
According to it, the most polluted city in the world is the capital of Afghanistan — Kabul. And the least polluted is the Japanese Kobe city.
Particles PM2.5 is an air pollutant, which includes both solid microparticles and tiny droplets of liquids. The smallest pieces of soot, asphalt and car tires, particles of mineral salts (sulfates, nitrates), heavy metal compounds (mainly oxides), biological pollutants (some allergens and microorganisms) also belong to PM2.5.
By the way, officials of the State Agency for Environmental Protection and Forestry of Kyrgyzstan do not recognize the data of these sensors. But official data of the agency are not available, especially online.