The dataset shows the areas where the annual limit value for nitrogen dioxide (40 µg/m3) is exceeded or is in danger of being exceeded.
The exceeding area is assessed and updated annually, at the end of the year in question. The assessment is carried out not only on the basis of the monitoring results for that year, but also taking into account the monitoring results and weather conditions of previous years.
The data is in a geographic dataset format (.shp and WMS interface). It can be downloaded from the map service at kartta.hsy.fi (under “Latauskori”) and from these pages as a Shapefile.
Via the WMS interface, data is available from 2004 onwards.
Nitrogen dioxide concentrations and exceeding the limit value are affected by traffic emissions and the ventilation of the area. Concentrations of air pollutants are higher on streets lined with tall and continuous buildings. The dilution of air pollutants is weaker in such areas.
WMS API: https://kartta.hsy.fi/geoserver/wfs, layer: No2_ylitysalueet_VVVV
- katu: street name
- raja_arvo: limit value: indicates whether the annual NO2 limit value is exceeded or in danger of being exceeded in the area in question
- arviovuosi: year of assessment of the exceeding area