Two Neighbouring Municipalities Join Copenhagen’s Air Pollution Alert System

Residents in Tårnby and Frederiksberg municipalities will soon gain access to real-time forecasts of local air pollution levels through the Danish app “Byens Luft”, developed by the City of Copenhagen for people who are especially vulnerable to poor air quality.

The app works much like a weather forecast, providing information on whether air pollution is expected to be elevated now and over the coming four days. It is primarily targeted at citizens with heart or respiratory conditions, but will now be expanded beyond Copenhagen through new forecast points in both Tårnby and Frederiksberg. The additional locations are being coordinated with the National Centre for Environment and Energy (DCE) at Aarhus University, which provides the data foundation behind the app.

According to Copenhagen’s Mayor for Health and Care, Sisse Marie Welling (SF), expanding the system makes it possible for more people to follow pollution levels where they live. She emphasises that cooperation across municipalities is crucial, as air pollution does not stop at municipal borders. Welling notes that more than one in seven Copenhageners are considered particularly vulnerable and that polluted air causes thousands of illnesses annually and more than 400 premature deaths each year.

Frederiksberg Mayor Michael Vindfeldt (S) also welcomes the initiative, stressing that many residents move across municipal borders every day. He points out that Frederiksberg has long worked to improve air quality, for example by banning older wood stoves, planting trees that absorb pollution and improving conditions for pedestrians, cyclists and public transport users. However, he underlines that a large proportion of pollution comes from outside the municipality, and therefore a broader effort is needed.

Tårnby Mayor Allan S. Andersen (S) highlights that the app gives vulnerable groups a practical tool to protect themselves in everyday situations, and sees the initiative as a strong example of how municipalities can collaborate on cross-border environmental challenges.

The app currently includes warnings for substances regulated by the EU and WHO: fine particles (PM2.5), coarse particles (PM10), nitrogen dioxide (NO2) and ozone (O3). In the future, it may cover additional pollutants such as ultrafine particles and black carbon, subject to scientific validation. Users receive automatic notifications when pollution reaches “very high” levels, and can choose to receive alerts at “high” levels as well. The app also offers advice for vulnerable groups, and further guidance is available on an accompanying website.

With the addition of Tårnby and Frederiksberg, the service now covers around 815,000 residents, and other municipalities may join if they wish. In Copenhagen alone, approximately 90,000 citizens are considered particularly vulnerable to air pollution.