Air pollution - State and impacts (Sweden)

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