High concentrations of particulate matter (PM10) and nitrogen dioxide constitute the greatest air quality problems in Sweden’s population centres. Several municipalities exceed environmental quality standards for PM10, which correspond to EU’s threshold value. The Swedish environmental quality standard for nitrogen dioxide, which is more stringent than the EU threshold value, is also exceeded in several municipalities. The previous declining trend for many substances appears to have levelled off. Concentrations of PM2.5 are relatively low and the EU threshold value is not exceeded anywhere in the country. The highest concentrations of PM2.5 are found in southern Sweden.

Particulate matter (PM10) is the air pollutant that causes the most severe health problems in Sweden’s population centres. High concentrations can impair respiratory functions and affect normal lung development. According to Swedish studies, particulate matter is believed to cause between 3 000 and 5 000 premature deaths annually in Sweden, which corresponds to a shorter average life span of about 6–12 months.

b) What are the state (S) and impacts (I) related to this theme, including impacts on the natural environment and human health/human well-being, both at national level as well as in transboundary terms? 

High concentrations of particulate matter (PM10) and nitrogen dioxide constitute the greatest air quality problems in Sweden’s population centres. Several municipalities exceed environmental quality standards for PM10, which correspond to EU’s threshold value. The Swedish environmental quality standard for nitrogen dioxide, which is more stringent than the EU threshold value, is also exceeded in several municipalities. The previous declining trend for many substances appears to have levelled off. Concentrations of PM2.5 are relatively low and the EU threshold value is not exceeded anywhere in the country. The highest concentrations of PM2.5 are found in southern Sweden due to long-range transboundary transport of air pollution.

Particulate matter

Particulate matter is the air pollutant that causes the most severe health problems in Sweden’s population centres. High concentrations can impair respiratory functions and affect normal lung development. According to Swedish studies, particulate matter is believed to cause between 3 000 and 5 000 premature deaths annually in Sweden, which corresponds to a shorter average life span of about 6–12 months.

Nitrogen dioxide

Elevated concentrations of nitrogen dioxide can have negative impacts on both health and the environment. The concentrations of nitrogen dioxide that exist in Sweden’s population centres can, for example, aggravate asthma or respiratory problems for those already afflicted. In nature, nitrogen dioxide fallout causes acidification and eutrophication. In addition to its health effects nitrogen dioxide is also an important contributor to the formation of ground-level (tropospheric) ozone, which in turn can affect health and the environment.

Tropospheric ozone

Occasions with high peak concentrations of tropospheric ozone are diminishing, but problems with elevated concentrations still exist in all parts of the country. The EU target value for 2010 for protection of human health is met. See chart of ground-level ozone in air at the Environmental Objectives Portal (in Swedish): http://www.miljomal.se/Systemsidor/Indikatorsida/?iid=104

Sulphur dioxide

Sulphur dioxide has historically been a serious air pollutant in Sweden. Today the concentrations are very low. The highest concentrations are now to be found in coastal cities, primarily in southern Sweden. This is due in large part to influx from the Continent and emissions from shipping. See chart and map of sulphur dioxide in air at the Environmental Objectives Portal (in Swedish). It shows SO2 in urban background in the winter half of the year: http://www.miljomal.se/Systemsidor/Indikatorsida/?iid=125&pl=1

Despite a marked reduction in sulphur fallout, recovery from acidification will take a very long time. See chart and map of deposition of sulphur at the Environmental Objectives Portal (in Swedish): http://www.miljomal.se/Systemsidor/Indikatorsida/?iid=101&pl=1  

c) What are the related key drivers (D) and pressures (P) at national level?

Important sources of air pollution are road traffic, energy production, industry and shipping. With respect to PM10, the main cause of high concentrations is road-wear particles generated by the use of studded tyres. Shipping has a major impact on both the concentration and deposition of nitrogen and sulphur and thereby affects water, air and land environments. Twenty-five percent of the atmospheric fallout of nitrogen over the Baltic Sea comes from international shipping. To a large extent, long-distance transport impacts ozone concentrations.

Sources outside Sweden are important

The concentrations of particulates (PM2.5) are affected by exhaust emissions and long-range transboundary pollution. In South Sweden more than 50 % of the anthropogenic PM2.5 present in ambient air monitored in regional background originates from sources outside Sweden. Despite the low concentrations, it is important that measures be implemented, both nationally and internationally, so that the population’s exposure to PM2.5 diminishes to improve citizens’ health. It has not been possible to establish a threshold under which no health effects arise.
 

d) What is the 2020 outlook (date flexible) for the topic in question and how will this affect possible impacts on the natural environment and human health/well-being?

The previously positive trend towards improved air quality in Sweden’s population centres has tapered off and there is no evident trend at present.

Sweden has 16 national environmental quality objectives. The goals describe what quality and state of Sweden’s environmental, natural and cultural resources are ecologically sustainable in the long term. The goals need to be implemented within one generation – that is, by the year 2020 (2050 in the case of the climate objective).

More action is needed

The Clean Air environmental quality objective can be achieved if further action is taken. The values of the environmental quality objectives are more stringent than the environmental quality standards for air, but are not legally binding as the standards are.

e) Which responses (R) have been put in place or are planned at national level for the theme in question?

Important tools for improving air quality are the following: more stringent emission requirements for vehicles, mobile machinery, shipping, industries and single house heating with wood, but also environmental quality standards for outdoor air as well as the Swedish environmental objectives. The Clean Air, Natural Acidification Only and Zero Eutrophication environmental quality objectives are linked with air quality and deposition.

Reduction of sulphur dioxide depends largely on lower sulphur content in oil and the cleansing of power plant emissions. Indirectly, the transition to other types of energy such as nuclear power, wind power and hydroelectric power has contributed to the lower concentrations.

With respect to PM10, new regulation of the use of studded tyres is expected to affect concentrations during the next few years.

Action programmes are set up

Environmental quality standards for outdoor air are, for different types of air pollution, either threshold values or air quality objectives. The standards are either as stringent or more stringent than the threshold values specified in the EC directive for air quality. If the standards are violated, an action programme will be set up. Since 2002, four action programmes have been established for particles, and five for nitrogen dioxide. Important action areas within Sweden are transportation, energy supply and physical planning. A survey conducted in 2008, however, questioned the effectiveness of the action programmes on air quality. The problem may be that the programmes are not optimally designed, that the costs and impacts are difficult to calculate and that measures decided upon have not been carried out. However, the system is under development.

International actions are also important. Sweden participates in the work with the EU Air Quality Directive and with the ceiling directive for air pollutants as well as international conventions, for instance the UN Convention of Long-range Transboundary Air Pollution (CLRTAP).