Air pollution - State and impacts (Finland)

Air quality in Finland is generally good, so the local impacts of air pollution are fairly limited. However, during periods when certain atmospheric conditions prevail – particularly atmospheric inversions in winter and spring – concentrations of pollutants in the air in Finnish cities may compare to those observed in cities of similar size elsewhere in Europe.

Air quality monitoring is a responsibility of the municipalities. In some cases, also the enterprises are involved. The Finnish Meteorological Institute (FMI) takes care of the national background air quality monitoring[1]. Air quality information is collected in the national air quality portal established and maintained by the FMI. The portal displays a real time air quality map of Finland (Air quality now) and the results of the air quality measurements over time. The full set of data and graphs can be found in Pollutants in the air (in Finnish).

Below are two figures showing the situation with concentrations well below the EU limit values.

Figure 2. Annual mean and number of exceedance days of PM₁₀ in 2008 in Finland

Even if the annual averages of PM₁₀ are below the limit value, the daily values, especially in the springtime, may be too high.

Nitrogen dioxide is one example of a pollutant where Finland may have problems in reaching the EU limit value in 2010. Nowadays, nitrogen dioxide concentration levels in the largest city centres are mainly below the EU annual limit value (40 µg/m³). However, in certain street canyons in downtown Helsinki with the highest traffic volumes, the annual limit value may be exceeded.

Figure 3. Monthly mean NO₂ concentrations in 1994–2008 (grey lines) and the modelled seasonal component combined with the generalized least-squares regression trend (black lines). The yearly changes of NO₂ concentrations are also given (%/yr)[2]

Ozone concentrations in the air

In Finland, the highest ozone concentrations are usually measured in background areas in spring and summer. The citizens must be informed when the hourly value of the ozone concentration exceeds 180 µg/m³ but such concentrations have occurred very rarely. The EU target value for 2010 to protect the human health means that the ozone concentrations (8 hour moving average) should be below 120 µg/m³ with a maximum of 25 exceedances annually. Concentrations over 120 µg/m³ occur in the rural background stations less than 25 times in a year. (Ozone)

The EU target value for 2010 for the protection of vegetation is (AOT40) 18 000 μg/m³·h averaged over five years and it has not been exceeded.

Figure 4. Number of exceedances of O₃ in 2006–2008 in Finland

It is not clear that Finland will meet the EU long-term objectives for ozone concentrations. Until now the long-term objective for the protection of human health has been exceeded everywhere in Finland, and the objective for the protection of vegetation is exceeded in a greater part of Finland. There is clear variation in the ozone concentrations between the years.

Polycyclic aromatic hydrocarbons

Monitoring of concentrations of polycyclic aromatic hydrocarbons (PAH) is still too scarce to draw conclusions. However, there are indications that short periods of elevated concentrations both in urban and rural environments are possible. They are related to either wintertime increase of PAH emissions from residential wood combustion for heating, industrial emissions or summertime regional transportation from wildfires.

Figure 5. Examples of benzo(a)pyrene concentrations in 1999-2006 in Finland

Human health

Human health problems are caused by particulate matter, carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide and total reduced sulphur, volatile organic compounds, polycyclic aromatic hydrocarbons, and heavy metals. In connection with the urban air pollution, fine particles (PM_2.5) pose the most severe health threat.

In the concluding report[3] of a recent Finnish study (PILTTI) it is estimated that fine particles from domestic combustion and road traffic caused slightly over 1 000 premature deaths in Finland in 2000. The estimate for 2020 is lower: about 450 cases of premature death (pp 43–48). According to an earlier Finnish estimate, air pollution, especially by particles, causes 200–400 premature deaths annually, 30 000 cases of increased asthma symptoms, and 30 000–40 000 respiratory infections in children.[4] The estimate of premature deaths is clearly higher in the results of PILTTI than in the older estimates. Some European studies suggest even higher numbers of premature deaths. A report[5] from the European Topic Centre on Air and Climate Change presents a map of Europe showing an estimate of 1 500–2 500 premature deaths in Finland.

Deposition of acidifying[6] and eutrophying air pollutants[7]

The sulphur deposition has decreased by 50–60 % since the late 1980s. The decrease in deposition of nitrogen compounds is less significant: 30–40 % (Graphs and maps of acid deposition, Finnish Environmental Administration (in Finnish)). The acidity critical load is exceeded in southern Finland and in parts of central and northern Finland (Critical loads, Finnish Environmental Administration (in Finnish)). The ecosystems most sensitive to acidification are the nutrient-poor lakes and forests of northern Finland, whose natural buffering capacity is already weak. Some 5 000 smaller lakes in Finland are now considered to be recovering well from serious acidification problems. Finland’s vital groundwater reserves are recovering, too, although it may take decades for groundwater to recover completely.

The area and volume of the Gulf of Finland is only a tenth of the whole Baltic Sea. In proportion to the area, Gulf of Finland receives a three-fold load compared to the other parts of the Baltic Sea. The annual load to the Gulf of Finland is more than 7 000 tonnes of phosphorus and nearly 120 000 tonnes of nitrogen. The airborne load of nitrogen is almost 20 % of the total load. (Eutrophication in the Baltic Sea, Eutrophying loads (in Finnish)). The airborne nitrogen affects more directly the eutrophication process than the pollution load from land. A recent study proposes that during summer ships may cause up to 50 % of the nitrogen deposition in some areas of the Baltic Sea[8].