2,400,000 inhabitants
surface area: 6,519 km2

Capital of Sweden & the most populous city among the Nordic countries.

Climate: Summers show average daytime high and low temperatures of 20–25 °C and 13 °C, respectively, while winters generally bring cloudy weather


Which pressures?

Air Quality  and  Health  



Environmental pressures targeted by SMURBS

 Air Quality: In the long term, ambient air quality in Stockholm has significantly improved and downward trends are observed for most air pollutants, caused by targeted and effective measures on emissions. Still, PM10 levels can still be high during spring. In terms of exceedances, nitrogen dioxide (NO2) is the main problem, primarily due to NOx emissions from diesel vehicles. In order to meet the environmental quality objectives, further actions for the improvement of air quality are necessary. Sweden has a stricter limit value for NO2than the EU Air Quality Directive– a daily mean value of 60 µg/m3not to be exceeded for more than 7 days. Also, the city needs to provide the public with easily accessible and detailed information on the air quality for the coming days.

 Health: Even though the air quality is relatively good in Stockholm compared to other cities, air pollution exposure poses an increased risk of adverse health effects. The major part of the premature mortality associated with air pollution exposure in Stockholm is related to local emissions, with road traffic and residential wood combustion having the largest impact.

High levels of road dust (coarse particles), ozone, and birch pollen occur simultaneously during the spring in Stockholm. Studies have shown that exposure to high levels of air pollution may exacerbate adverse health symptoms associated with exposure to birch pollen. There are also many epidemiological studies in Stockholm showing associations between air pollution exposures and different diseases, such as the higher risk of incident stroke associated with exposure to black carbon, children growing up in the inner city are at doubled risk for reduced lung function, people who have lived 30 years in the city have 50% higher risk of myocardial infarction, and high ozone exposure increases the risk of premature birth. Approximately 5%-10% of all hospital admissions for airway diseases are due to road traffic emissions.



The implementation of smart urban solutions

 Air Quality: This SMURBS activity focuses on providing prognoses of hourly mean air pollutant concentrations for the next 3 to 4 days considering both local and regional air pollution emissions. Maps are provided with concentrations at a resolution of 100 by 100 meters as well as concentrations along all streets considering the effects of buildings (increased levels in street canyons). The air pollutants included are the ones that contribute most to exceedances of EU limit values and at the same time are mainly associated with adverse respiratory effects: i) PM10, mainly as a marker for road dust; ii) ozone as a marker for photochemical oxidants; iii) NOx (and NO2) as a marker for particles and gases from local vehicle exhaust.

 Health: A web platform and smartphone app delivering GIS maps on the current situation and 4-day forecasts for an Air Quality Health Risk Index, AQHI, with 100x100m resolution. The index is based on epidemiological studies in Stockholm showing the association between air pollution (PM10, NOx, O3), birch pollen, and increased hospital admissions in respiratory diseases. The AQHI represents the increasing percentage in hospital admissions due to all key air pollutants and pollen. Therefore, AQHI is based on “real” health risks not on threshold limit values.

The smartphone app allows users to provide their own diagnoses on their health status. This makes it possible for users to evaluate which pollutant (PM10, O3 or NO2) or birch pollen that causes the most negative health impact. The AQHI is based on epidemiological studies on the associations between acute hospital admissions and exposure to pollutants and pollen. The system will also produce prognoses of individual pollutants and pollen. By using a diary provided in a mobile phone app, sensitive persons/patients can record their health status and compare with the prognosis information to better understand the causes of their respiratory problems.



Partners involved in the design and implementation of the solutions

Stakeholders involved: 


Palynological laboratory in Stockholm

Swedish Environmental Protection Agency

Karolinska Institute

Eastern Sweden Air Quality Association

The Asthma and Allergy Association

Environmental and Health Administration of the city of Stockholm

City administrations of Malmo

City administrations of Gothenburg

City administrations of Umea