HSY monitors air quality in the Helsinki metropolitan area at new locations in 2024 – The monitoring investigates the impact of wood burning, traffic and harbour operations on air quality

The Helsinki Region Environmental Services Authority (HSY) has 11 air quality monitoring sites in the Helsinki metropolitan area. Four of these sites change their location every year or two. This year, they are located at Teollisuuskatu and Vuosaari Harbour in Helsinki, in Lintuvaara in Espoo and along Hämeenlinnanväylä in Vantaa.

Mobile sites provide information on the impact of wood burning, heavy traffic and harbour operations on air quality

HSY is responsible for monitoring the air quality in the Helsinki metropolitan area and the rest of Uusimaa. Air quality is monitored at both permanent and mobile monitoring sites. The permanent monitoring sites are located in the same place every year and are used to monitor the development of air quality over a long period of time. Mobile sites change their location every year or two years. The mobile sites allow air quality to be monitored in several different areas, and they are placed in different types of environments. The locations are selected together with the municipalities.

– The aim of the monitoring in 2024 is to find out how wood burning, heavy traffic and a harbour area impact air quality, says Hanna Manninen, Head of HSY’s Air Quality Unit.

This year, the mobile air quality monitoring sites are located at Teollisuuskatu and Vuosaari Harbour in Helsinki, in Lintuvaara in Espoo and along Hämeenlinnanväylä in Vantaa.

– In Lintuvaara in Espoo, we monitor the impact of smoke from wood burning on the breathing air in a detached housing area. The monitoring at Vuosaari Harbour in Helsinki, in turn, will provide us with information on the impact of the harbour’s ship traffic and the operations in the harbour area on air quality, Manninen says.

The air quality impacts of traffic emissions are investigated in two different environments. The monitoring at Hämeenlinnanväylä will show how heavy traffic impacts the air quality along a main route. The Teollisuuskatu monitoring site in Helsinki will also indicate the impact of emissions from heavy traffic, but the monitoring location is a street with many tall buildings. Monitoring has been carried out previously as well at all the 2024 sites, with the exception of Teollisuuskatu.

Kirkkonummi also has a mobile site in 2024

Elsewhere in Uusimaa, there is one permanent and one mobile air quality monitoring site. This year, the mobile monitoring site is located in the centre of Kirkkonummi at Lindalintie.

– The monitoring in Kirkkonummi will provide information on what the air quality is like in a town centre area in the municipalities in Uusimaa, Manninen says.

The permanent monitoring site for the rest of Uusimaa is located in Lohja. The monitoring is used to determine the background level of the urban environment in Uusimaa. The site is located far away from busy streets and the concentrations of air pollutants measured there represent the level to which people are generally exposed in residential areas in the centres of the municipalities in Uusimaa.

HSY carries out supplementary monitoring also in other locations

In 2024, in addition to Lintuvaara, HSY monitors the impact of wood burning on air quality in detached housing areas in Tapanila in Helsinki, Päiväkumpu in Vantaa and Sudetti in Karkkila. There is no actual monitoring site at these locations, but individual measuring instruments are used to determine carcinogenic PAH concentrations, among other things. The permanent monitoring site in Vartiokylä in Helsinki also provides information on the impact of wood burning on the general air quality in a detached housing area.

Individual measuring instruments are used to monitor street dust concentrations in approximately ten different locations along major routes and main streets. Similarly, the impact of traffic exhaust gases on air quality is monitored in approximately 40 locations.

In 2024, HSY also monitors the impact of construction site dust in Espoo and the studded tyre ban experiment in Helsinki on air quality. In addition, HSY monitors the air quality in Vantaa within the area affected by the airport.

Information on air quality monitoring

• Air quality in the Helsinki metropolitan area can be viewed in real time at hsy.fi/en/air-quality-and-climate/air-quality-now
• HSY has 11 air quality monitoring sites in the Helsinki metropolitan area and two elsewhere in Uusimaa. The air quality monitoring sites have several measuring instruments that are used to monitor several different air pollutants.
• Mobile air quality monitoring sites in 2024:
  • In Lintuvaara, the monitoring covers concentrations of nitrogen oxides, thoracic particles, fine particles, PAH compounds and black carbon.
  • In the Vuosaari Harbour area, the monitoring covers concentrations of nitrogen oxides, sulphur dioxide, thoracic particles, fine particles as well as the LDSA and number of particles.
  • Along Hämeenlinnanväylä, the monitoring covers concentrations of nitrogen oxides, thoracic particles and fine particles.
  • At Teollisuuskatu, the monitoring covers concentrations of nitrogen oxides, thoracic particles and fine particles.
  • In Kirkkonummi, the monitoring covers concentrations of nitrogen oxides and thoracic particles.
• The permanent air quality monitoring sites in Helsinki are located at Mannerheimintie 5 and Mäkelänkatu 50, at the Kallio sports field and in Vartiokylä.
• In Espoo, air quality is permanently monitored in Leppävaara and Luukki.
• In Vantaa, the permanent monitoring site is located in Tikkurila.
• Elsewhere in Uusimaa, air quality is permanently monitored in Lohja.
• In addition to monitoring sites, air quality is monitored with smaller individual measuring instruments at several different locations in the Helsinki metropolitan area and elsewhere in Uusimaa.

Information on air pollutants

• Nitrogen oxides in the breathing air originate from traffic emissions, especially from diesel cars and heavy vehicles. Of the nitrogen oxides, nitrogen dioxide is the most harmful to health. It contracts the bronchi in high concentrations and increases respiratory symptoms, especially in children and asthmatics.
  
  
• Thoracic particles are mostly street dust suspended by traffic. Street dust can cause symptoms of irritation, such as rhinitis, cough, as well as itching and burning of the throat and eyes in anyone. Street dust is particularly harmful to population groups sensitive to air pollutants, such as asthmatics, young children, the elderly and people with coronary artery disease or chronic obstructive pulmonary disease. Street dust often aggravates the symptoms of people with heart and respiratory conditions.
  
  
• Fine particles are mainly generated from traffic and wood burning emissions. In addition, they are transported to the Helsinki metropolitan area from outside the country’s borders. Fine particles are considered particularly harmful to health, as they are able to penetrate into even the peripheral areas of the lungs.
  
  
• Black carbon (BC) refers to strongly light-absorbing particles that contain a substantial amount of inorganic carbon. Black carbon, or soot, is formed by incomplete combustion. There are organic compounds harmful to health (e.g. PAHs) and metals attached to soot particles. The emission sources include old diesel vehicles and machinery, wood burning in fireplaces and ship traffic. Black carbon is also transported to Finland from outside the country’s borders. Black carbon amplifies global warming as it binds solar radiation both in the atmosphere and on snow.
  
  
• PAH compounds, or polyaromatic hydrocarbons, may in some places exceed the target value set by the EU in detached housing areas where a lot of wood is burned. PAH compounds are created through incomplete combustion. Many PAH compounds increase the risk of cancer.
  
  
• LDSA: The lung-deposited surface area, or LDSA, describes the surface area of the particles that travel and settle in the deepest parts of the respiratory system all the way to the alveoli. The most important emission sources in the Helsinki metropolitan area include vehicles and machinery, wood burning in fireplaces as well as ship and air traffic. The LDSA concentration is also increased by air pollutants transported from outside Finland’s borders.
  
  
• The particle number concentration of particles in the air is monitored in addition to the traditional mass concentration. With regard to city air, the number concentration provides a particularly good representation of ultrafine particles from nearby exhaust gas emissions, which travel all the way to the peripheral areas of the respiratory system. The most important emission sources in the Helsinki metropolitan area include vehicles and machinery as well as ship and air traffic. Emissions from wood burning increase the number concentration only slightly in detached housing areas. The number concentration is also significantly affected by particles generated from gases in the atmosphere, which are formed most during sunny weather in spring and early summer.