The responsibility of the municipality
Laws and restrictions set minimum requirements for local air quality. It is the responsibility of the City of Oslo to ensure that these are complied with. If the air quality in Oslo is getting too bad, the municipality breaks the law.
The Pollution Control Regulation defines minimum air quality requirements. The regulations specify limit values for nitrogen dioxide and dust particles.
For dust particles, limit values have been largely observed in Oslo in recent years, both on a daily and annual basis, but in 2016 the requirements for the regulations were tightened. The background was research that showed major health risks at low concentrations of dust particles than previously assumed.
In addition, there are health-based air quality criteria from the Norwegian Institute of Public Health and the Norwegian Environment Agency.
The air quality criteria are stricter than the limit values in the regulation. The City Council aims to keep local emissions of dust particles under the levels recommended by the public health authorities.
Road traffic and heating biggest polluters
The largest sources of air pollution in Oslo today are road traffic and heating. These sources release dust particles and nitrogen dioxide.
Nitrogen dioxide originates predominantly from exhaust, especially from diesel-powered vehicles, while the main sources of dust particles are road dust from pavement wear and from wood burning.
Locally, construction and shipbuilding or ship and port activities can also contribute significantly to pollution. In addition, pollution is brought to Oslo as a result of wind currents from other regions and countries.
In Oslo there are 13 measuring stations that measure the main components of Oslo’s ambient air. The collected data can be viewed at www.luftkvalitet.info/oslo.
After 2013, the values for nitrogen dioxide have decreased in Oslo. This applies both to areas close to heavily trafficked roads and to measuring stations that provide a representative image of the overall air quality in Oslo.
The decline is due to a combination of emission reductions due to increasingly cleaner cars and relatively good meteorological conditions.
Nevertheless, exceedances of the annual average limit values are still observed at some measuring stations in highly trafficked areas, and concentrations are close to the limit value in several other places. The pollution limits are exceeded because the general levels of nitrogen dioxide are too high.
The number of times the limit values are exceeded can vary significantly from year to year. The highest levels are measured in the winter months due to more stable weather conditions combined with larger emissions, for instance from a cold start of cars with an internal combustion engine.
The City of Oslo has its own assessment of measures for air quality, which was revised in 2017. Its aim is to find measures that ensure compliance with the limit values in Oslo by 2020.
In February 2018, the City Council adopted a revised action plan for better air quality in Oslo 2018-2020. The action plan consists of over 40 points and contains both immediate steps in case of high levels of air pollution as well as general measures for better air.
Oslo municipality has a contingency plan for high levels of air pollution from nitrogen dioxide covering large areas of the city, for a pre-determined duration. In such situations, emergency measures, such as diesel bans, can be implemented if needed.
The general measures include, among other things, environmental differentiation of vehicles, emission reduction from Oslo port, measures for the transition to electric vans, and measures to reduce emissions from wood burning.
Implemented measures, such as changed tariffs on toll roads, fees for the usage of snow tires with metal studs, cleaning and dust reduction, and environmental speed limits have resulted in reduced levels of nitrogen dioxide and dust particles.