Which respect to industrial practices the most polluted region of Russia is located around?

The most polluted region in Russia with respect to industrial practices is located in the south, including the cities of Rostov-on-Don, Volgograd, and Astrakhan. This area is home to a number of heavy industries, including oil refining, chemical production, and metalworking, which generate large amounts of pollutants. Additionally, the region is also home to several thermal power plants, which contribute to air pollution. The combination of these factors has resulted in the south of Russia being designated as the most polluted region in the country.