Russia's Natural Resources Ministry has named the 35 cities and towns with the country's highest air pollution levels.
Environmental officials aim to create a system that will force the highest-polluting regions and businesses to report their emission levels and take steps to reduce them.
Here's a closer look at some of the cities that made the list:
The 35 towns and cities are located in 17 regions. Most of the cities on the list are located in the Ural Mountains, Siberia or the Far East.
Alava (CC BY-SA 4.0)
The air in these cities has been dangerously contaminated for at least three out of the last five years, the Natural Resources Ministry reported.
Zverkov (CC BY-SA 3.0)
The government is expected to announce which regions will be part of the Clean Air initiative by June 30. The project aims to limit emissions in the country's most polluted regions.
Аноним 03 / VK (CC BY-SA 4.0)
Chita, Zabaikalsky region
Cities chosen for the Clean Air project will have to reduce their emissions of pollutants by 20%. The project is especially aimed at fighting pollution in major industrial centers.
Petrovsk-Zabaikalsky, Zabaikalsky region
So far, just 12 cities are on the Clean Air list, including industrial centers Krasnoyarsk, Magnitogorsk, Novokuznetsk, Chelyabinsk and Omsk.
Michael G. Schroeder (CC BY-SA 4.0)
Yuzhno-Sakhalinsk, Sakhalin region
When air pollution levels rise substantially above permitted levels, meteorologists can declare a “black sky” emergency. The term means that pollution has become so thick it takes harmful particles more time to dissolve in the air.
kikiwis (CC BY 3.0)
Komsomolsk-on-Amur, Khabarovsk region
PM2.5 are considered the most common among harmful pollutants and are typically emitted while burning wood or fossil fuels. PM2.5 can also be emitted at coal mining sites.
olegushakov (CC BY-SA 3.0)
Chegdomyn, Khabarovsk region
Studies have linked PM2.5 pollution to heart, respiratory and neuro-psychological diseases. The particles can travel from thousands of kilometers but tend to inflict greatest harm to those living near the pollution source.
Ussuriysk, Primorye region
The pollution becomes more noticeable during winter, when the cold weather requires more fossil fuels to be burned. Additionally, harmful particles fall on snow and produce “black snow,” a familiar sight in Novokuznetsk and other heavily-polluted cities.
Andshel (CC BY-SA 4.0)
Achinsk, Krasnoyarsk region
Air pollution is a recurring problem for such regions as Kuzbass, where cities like Novokuznetsk are located.
Krasnoyarsk, Krasnoyarsk region
Russia aims to create a new system to monitor air pollution. The system is aimed at monitoring greenhouse gases but it will also help to estimate true levels of general air pollution across the country, officials have said.
Roman Herda (CC BY-SA 4.0)
Lesosibirsk, Krasnoyarsk region
Heavy-polluting companies will be required to install monitoring devices at their industrial sites by the end of 2022.
Marco Fieber / flickr (CC BY-NC-ND 2.0)
Minusinsk, Krasnoyarsk region
Officials in Minusinsk and other polluted cities are receiving increasing numbers of complaints from locals who demand tougher environmental regulations.
danilka7595 (CC BY 3.0)
Norilsk, Krasnoyarsk region
The Krasnoyarsk region has the highest air pollution level in the country, with the far-northern city of Norilsk having the worst pollution in the region.
Alexey V. Kurochkin (CC BY-SA 4.0)
Kyzyl, republic of Tuva
Authorities say that pollution in Russia's regions could be much higher in reality, as emissions are frequently under-reported.