Particles killing half a million

Air pollution by fine particles is estimated to cause half a million premature deaths in European countries every year.

According to a recent study by the European Topic Centre on Air and Climate Change (ETC/ACC) on behalf of the European Environment Agency (EEA), pollution of fine particles is associated with more than 455,000 premature deaths every year in the EU’s 27 member states, corresponding to almost 4.5 million years of life lost.

Maps showing pollutant concentrations may serve as input to studies assessing the health impacts of exposure to air pollution. In the case of fine particles (PM2.5), monitoring activity is as yet too limited to prepare such a concentration map for Europe based solely on monitoring data. A mapping procedure was therefore developed that combines the scarce PM2.5 monitoring data with the more abundant PM10 monitoring data. Figure 1 shows the resulting PM2.5 map, which was used to compare the current (2005) concentrations with the limit and target values as laid down in the EU’s air quality directive (see box).

Small particles targeted in EU directive

In May 2008, the EU adopted a new air quality directive establishing health-based standards and objectives for several air pollutants, including PM2.5. An annual mean PM2.5 concentration of 25 μg/m3 is laid down as a target value to be attained in 2010 and as a binding limit value to be met in 2015. There is also a provisional limit value of 20 μg/m3 for 2020.

In order to ensure more widespread health benefits, the directive introduced a mechanism aimed at a general reduction in concentrations. The average exposure indicator (AEI) is the average of concentrations at urban background locations throughout a country and it reflects the population exposure. A legally binding cap of 20 μg/m3 is to be attained by 2015, and a percentage reduction is required to be attained by 2020, determined on the basis of the AEI value in 2010. According to the study, the exposure reduction target varies between countries, ranging from 10 per cent in Scandinavia to more than 25 per cent in eastern European countries.

Note: PM stands for Particulate Matter. PM2.5 are particles smaller than 2.5 μm in diametre, which is about 20 times smaller than human hair.

Figure 1: Annual average PM2.5 concentrations for the year 2005.

The mapped results indicate that the annual mean level of 25 micrograms PM2.5 per cubic metre (μg/m3) is exceeded widely in Europe. This concentration – which in the directive is set as a target for 2010 and as a limit value for 2015 – was exceeded in twelve out of the 27 EU member states. As the spatial resolution of the PM2.5 map is limited to an area of 10 by 10 kilometres this is likely to be an underestimate – more exceedances are to be expected at hot-spot locations, such as city centres, or areas with intensive road traffic.

It is estimated that nine per cent of the population was exposed to levels above the PM2.5 limit value. In the same year (2005), more than a quarter of the population was exposed to concentrations above the PM10 short-term limit value (not more than 35 days per year with a daily mean above 50 μg/m3). This indicates that the new PM2.5 limit value for 2015 is less stringent than the short-term PM10 limit value, which was to be attained by 2005.

In this context it could be noted that the World Health Organisation recommends an air quality guideline value of 10 μg/m3 as annual mean. The map indicates that more than 90 per cent of the population in Europe is exposed to concentration above this guideline.

In ten member states the average exposure indicator (see box) was well above the exposure concentration obligation of 20 μg/m3 to be met in 2015. In another five countries this indicator was around the level of 20 μg/m3.

Austria  6900
Belgium 10700
Bulgaria 12300
Cyprus 1000
Czech Republic  13700
Germany 78000
Denmark 4200
Estonia 1000
Spain 35900
Finland 2500
France 34200
Greece 13400
Hungary  16200
Ireland 1400
Italy 65500
Lithuania 2800
Luxembourg  200
Latvia 2100
Malta 400
Netherlands 15000
Poland  39700
Portugal 10200
Romania 28700
Sweden 5400
Slovenia  1800
Slovakia 5800
United Kingdom 46200
Sum EU27 455200
Albania  2300
Bosnia and Herzegovina 3200
Switzerland 5000
Serbia and Montenegro 15100
Croatia  5800
Iceland 100
Norway 2700
Macedonia 2400
Sum Non-EU  36600
Total  492000

Table: Numbers of premature deaths per year attributable to exposure to PM2.5 (based on year 2005 pollution levels).

The geographic distribution of premature deaths attributable to exposure to PM2.5 is shown in figure 2, and the table provides country-by-country figures.

Figure 2: Premature mortality (expressed as deaths per 10,000 inhabitants/year) attributable to PM2.5 exposure at year 2005 pollution levels.

According to the study, PM2.5 pollution in European countries is associated with more than 492,000 annual premature deaths, corresponding to almost 4.9 million years of life lost (YOLL) every year. These include 297,000 premature deaths caused by cardiopulmonary diseases and 54,500 premature deaths attributable to lung cancer. These numbers agree well with estimates made for the EU25 in the European Commission’s Clean Air for Europe (CAFE) report, published in 2005.

Christer Ågren

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