Air pollution for Germany and Central Europe on a daily basis. Click image to start flow animation. (Source: RIU/FZJ)

Scientists of the Forschungszentrum Jülich (FZJ) and of the Rhenish Institute of Environmental Research at the University of Cologne (RIU) are calculating the level of air pollution for Germany and Central Europe on a daily basis and produce flow animations to show concentrations of NO2, Ozone and PM10.

Particulate matter consists of respirable solid or fluid particles and represents a health hazard. The particle sizes are differentiated in PM10 and PM2.5. The notation PM10 is an acronym for “particulate matter” and the size of the denoted particles. The numbers 10 and 2.5 mean that the particles maximum diameter is 10 and 2.5 µm. The EU directive 2008/50/EG on ambient air quality for Europe requires that the limit of 50 mg/m³ air measured at a station must not be exceeded on more than 35 days per year.

Responsible for increased particulate matter concentrations in the inner city with 30 - 50% is traffic with exhaust fumes and re-suspended particulate matter. Other combustion processes, industrial emissions, mineral dust or volcanic eruptions can also cause increased particulate matter levels. In Paris in March 2015 traffic was highly restricted and the government even partially banned automobile traffic.

Ozone is mainly concentrated in the ozone layer of the atmosphere and protects life forms against high energetic solar radiation. Ozone is gaseous at room temperature and due to its oxidizing effect it is capable of irritating the respiratory ducts. Amongst others ozone develops from the use of laser printers, copiers, or fax machines, and it is important to ensure adequate ventilation in office rooms. In the ambient air ozone originates from chemical reactions involving nitrogen dioxide and volatile organic compounds. The European Council has defined that the maximum daily eight-hour mean of 120 mg/m3 air must not be exceeded on more than 25 days per calendar year.

Nitrogen dioxide is a poisonous gas that is emitted by combustion of fossil fuels like oil or coal. Coal-fired power plants, industrial plants and motor vehicles are nitrogen dioxide emitter. According to the air quality directive of the European Council the one-hour-limit for nitrogen dioxide concentration of 200µg/m³ was introduced for health protection and must not be exceeded more than 18 times per calendar year. The limit value for the yearly mean concentration is 40µg/m³.