Information on air protection
Air pollutants are harmful gaseous or particulate substances derived from human activities or from natural sources.
The principal urban air pollutants in Finland are particles, nitrogen oxides, sulfur dioxide, carbon monoxide and organic compounds. Malodorous sulfur compounds are still an air quality problem in a few industrial districts. Air pollution affects both human health and the natural environment.
Local authorities monitor air quality and provide public information on this subject. HSY arranges air quality monitoring in the Helsinki Metropolitan Area. Also operators of different activities have a responsibility to be aware of the impacts of their activities on air quality, meaning that the energy producers and the Port of Helsinki also participate in the joint monitoring.
The methods of air quality monitoring are continuous and indicative measurements, dispersion modelling, bioindicator monitoring and emission inventories.
Pollutant concentrations in outdoor air are regulated by limit, threshold and target values and national guidelines. The limit values prescribed by the European Union define the maximum acceptable concentrations. Guideline values are less strict than limiting values, and serve as a basis for planning. Threshold values specify the levels at which residents must be notified immediately, and target values in turn provide guidance for reducing environmental and health impacts.
The four cities of the Helsinki Metropolitan Area have formulated air quality plans for the years 2008 - 2016 to improve air quality. These plans were prepared because the limit values for thoracic particles and nitrogen dioxide are exceeded in busy street canyons and in the city centre in Helsinki. Local authorities are responsible for taking steps to protect residents in the event of any sudden deterioration in air quality. The short term action plan specifying the necessary measures and responsibilities was revised in 2010.