Bad air quality prevails

92 per cent of the urban population were exposed to PM_2.5 concentrations in excess of the WHO guidelines in 2012. Photo: Astrid Westvang/flickr.com/ CC BY-NC-ND

More than nine out of ten urban citizens in the EU are exposed to harmful levels of the air pollutants PM_2.5 and ozone.

Air pollution problems in Europe are still far from solved. While policies have improved air quality overall, air pollution is still the main environmental health hazard, resulting in high costs for healthcare, unhealthy workers and nearly 450,000 premature deaths in the EU in 2011 (see AN 4/14, p. 26).

The annual air quality report from the European Environment Agency (EEA) collates data from official monitoring stations across Europe. It shows that almost all city dwellers are exposed to pollutants at levels deemed unsafe by the World Health Organization (WHO).

Between 2010 and 2012, up to 93 per cent of city dwellers were exposed to fine particulate matter (PM_2.5) concentrations above WHO guidelines and up to 98 per cent were exposed to ozone levels above WHO guidelines.

While emissions of the main air pollutants in Europe have continued to decline over the last ten years, due to the complex links between emissions and air quality this has not always resulted in a corresponding reduction in pollutant concentrations in ambient air, especially for PM and ground-level ozone.

Some key findings for the different air pollutants covered by the report are given below and summarised in the table.

Particulate matter (PM) is the most serious air pollution health risk in the EU, leading to health damage and premature mortality. The EU limit and target values for PM₁₀, which should originally have been met by 2005, were exceeded widely in 2012, with the daily limit value being exceeded in 21 countries, and one-fifth of the urban population being exposed to PM₁₀ concentrations higher than the daily EU limit value.

For 2012, the EEA report shows that 64 per cent of EU urban dwellers were exposed to PM10 concentrations that exceed the WHO guidelines, and 92 per cent of the urban population were exposed to PM2.5 concentrations in excess of the WHO guidelines.

PM in ambient air originates both from primary particles emitted directly into the air and from secondary particles produced as a result of chemical reactions of PM precursor pollutants, namely sulphur dioxide (SO₂), nitrogen oxides (NOx), ammonia (NH₃) and volatile organic compounds (VOCs). New research shows that PM concentrations can be considerably reduced by additional cuts in agricultural NH₃ emissions.

Ozone (O₃) can cause respiratory health problems and lead to premature mortality. It can also damage vegetation, including forest trees and agricultural crops. Ozone is a secondary pollutant, formed from precursor pollutants, primarily NOx, VOCs, methane and carbon monoxide. Exposure in cities is very high – 98 per cent of EU urban inhabitants were exposed to ozone concentrations above the WHO reference level in 2012, while 14 per cent were exposed to concentrations above the laxer EU target value.

Moreover, in 2011, one-fifth of arable land in Europe was exposed to ozone levels higher than the EU’s target value for vegetation protection, and only 12 per cent of the total agricultural area met the long-term objective (LTO) for ozone. The critical level set for protection of forests was exceeded across two-thirds of the total forest area in the EEA’s 33 member countries.

Nitrogen dioxide (NO₂) is associated with mortality and morbidity. It is also a major cause of eutrophication (over-fertilisation that may negatively affect biodiversity and cause excessive plant and algal growth in marine ecosystems) and acidification. NO2 also contributes to the formation of PM and ozone. In 2012, eight per cent of Europeans living in cities were exposed to NO2 levels above the EU limit values, which are set at the same level as the WHO guidelines.

Eutrophication is still a widespread problem – 63 per cent of the EU’s ecosystem areas and 73 per cent of the area covered by Natura 2000 protected sites were exposed to nitrogen deposition in 2010 that exceeded eutrophication limits.

Benzo(a)pyrene (BaP) is a carcinogen. In 2012, about one-quarter of the urban population in the EU was exposed to concentrations exceeding the EU target value, which must be met by 2013. As much as 88 per cent of EU urban citizens were exposed to levels above the estimated WHO reference level. The increase in BaP emissions in Europe in recent years, especially from domestic solid-fuel combustion, is therefore a matter of concern.

Sulphur dioxide (SO₂) causes acidification and contributes to PM formation. Emissions of SO₂ have been reduced significantly in recent years and 2010 was the first year that the EU urban population was not exposed to SO₂ concentrations above the EU limit value.

However, more than one-third of the urban population was exposed to SO₂ levels exceeding the stricter WHO guideline. While exceedances of the critical loads for acidification have fallen significantly over the last few decades, excess acid fallout was still occurring in seven per cent of the EU’s ecosystem area.

Carbon monoxide, benzene and heavy metal (arsenic, cadmium, nickel, lead, mercury) concentrations in outdoor air are generally low, localised and sporadic in the EU, with few exceedances of the limit and target values set by EU legislation. However, the deposition of heavy metals contributes to the build-up of these pollutants in soils and sediments, and since they are persistent in the environment they may bio-accumulate in food chains. Depositions of mercury are estimated to exceed the critical loads in more than half of the area of sensitive ecosystems in the EU.

Commenting on the report, EEA Executive Director Hans Bruyninckx said: “Air pollution is still high in Europe. It leads to high costs for our natural systems, our economy, the productivity of Europe’s workforce, and most seriously, the general health of Europeans.”

Christer Ågren

Air quality in Europe – 2014 report. EEA Report No 5/2014.

Table. Percentage of the urban population in the EU-28 exposed to air pollutant concentrations above the EU and WHO reference levels (2010–2012).