section_path: Environment/Air quality
section_name: Air quality
paragraph_text: Air quality
  
  Stockholm used to have problematic levels of particulates (PM10) due to studded winter tires, but by the 2010s they were below limits, after street-specific bans. Nitrogen oxides emitted by diesel vehicles were a problem in the 2010s, but by 2021 they were again below limits, after electric cars had started to replace diesel-driven ones, and pollution regulations for lorries had tightened. As of 2021, the pollutant that exceeds limits is ozone, due to global pollution. In 2021 the average levels for urban background (roof of Torkel Knutssonsgatan on Södermalm) were: NO 9.7 μg/m 3, PM10 9.5 μg/m 3, PM2.5 5.1 μg/m 3, soot 0.36 μg/m 3, ultrafine particles 6100/cm 3, SO 0.4 μg/m 3, ozone 53 μg/m 3. For urban street level (the densely trafficked Hornsgatan on Södermalm) the average levels were: NO 23 μg/m 3, PM10 17 μg/m 3, PM2.5 6.0 μg/m 3, soot 0.55 μg/m 3.