Today's poor air quality is primarily caused by several key factors:
- Particulate Matter (PM2.5 and PM10): Tiny particles originating from sources such as vehicles, industrial processes, wood-burning stoves, and even neighboring regions where coal and wood are heavily used for heating. These can penetrate deep into the lungs and have serious health impacts, including respiratory and cardiovascular issues.
- Ground-Level Ozone: Produced when pollutants from cars, power plants, and industrial facilities react with sunlight. Ozone levels may rise during sunny, stagnant conditions, leading to poor air quality that worsens in the afternoon and poses risks especially for sensitive groups.
- Nitrogen Dioxide and Other Gases: Emitted by burning fossil fuels at high temperatures, found in vehicle exhaust and industrial emissions. These contribute both directly to air pollution and indirectly to ozone formation.
- Weather Conditions: Stagnant air, little wind, or atmospheric inversion (often during winter or settled weather) trap pollutants close to the ground, preventing them from dispersing, which significantly aggravates pollution levels.
- Imported Pollution: In some regions, air quality can worsen due to pollution carried by winds from neighboring areas and countries. For example, particulate levels in cities like Berlin or Hamburg may be partially influenced by coal and wood burning in nearby regions.
On August 18, 2025, several world regions, including Madrid, reported elevated PM2.5 particulate levels, contributing to poor air quality alerts. Localized sources (cars, industrial emissions), weather conditions, and sometimes transboundary movement of pollutants all play a role in day-to-day air pollution fluctuations.
For most locations today, the most significant contributors are particulate pollution (PM2.5) and ozone , influenced by both local emissions and prevailing weather patterns.
