Nitrogen dioxide (NO2) is a dangerous toxic gas that causes respiratory symptoms, increases the risk of chronic diseases with prolonged exposure, and increases mortality. Auto transport is the main source of nitrogen dioxide in major Russian cities. Concentration of nitrogen dioxide correlates with the pollution of urban air in general.
For the ranking, environmentalists have used from Tropomi satellites from June 2018 to May 2019.
According to Greenpeace experts, development of zones with restricted movement of vehicles of low ecological class (Euro-3 and lower) should reduce the concentration of nitrogen dioxide. In addition, authorities should publish real-time air pollution monitoring data and take measures to address the problem of air pollution based on them.