Air pollution - State and impacts (Austria)

PM10

Despite substantial progress in reducing emissions especially during the 1980s, in recent years the limit value for the daily mean of PM10 of Directive 2008/50/EC (50 g/m not to be exceeded more than 35 times per year) was exceeded in several provincial capitals and small towns. The only larger Austrian town with PM10 levels below the limit value in most years is Salzburg. The sources that are mainly responsible include road transport, residential heating using solid fuels, the industrial sector and the building industry, as well as agriculture in rural areas and, to some extent, longdistance transport.

Figure 1 shows the average concentration and number of exceedances of all urban and suburban monitoring sites in Austria from 2001 to 2008. Especially in 2007 and 2008 the levels were rather low. This was on the one hand due to favourable meteorological conditions, on the other hand a result of national and international abatement measures.

Figure 2 shows the number of exceedances of the daily mean limit value at selected highly polluted sites in urban areas. The city experiencing the highest levels is Graz, which is caused by rather unfavourable dispersion conditions in an alpine basin.

The limit value for the annual mean of nitrogen dioxide of Directive 2008/50/EC (40 g/m) is exceeded in Austria occasionally, especially close to roads with heavy traffic. The main source of NO_x emissions in urban areas is traffic (see also Figure 13). Figure 3 shows the average annual mean concentrations of NO₂ in urban and suburban monitoring sites from 1993 to 2008. Until the year 2000, NO₂ levels were decreasing whereas in the years afterwards no statistical significant trend can be observed. In the year 2008, NO₂ concentrations were on the same level as in the year 2000, despite a reduction of NO_x emissions. At highly polluted sites, an increase in NO₂ concentrations was also observed (Figure 4). This is caused by an increase in primary NO₂ emissions due to exhaust aftertreatment systems of diesel passenger cars.

The target value for the protection of human health of Directive 2008/50/EC (120 μg/m not to be exceeded on more than 25 days per calendar year averaged over three years) was exceeded at 54% of all monitoring sites in Austria between 2006 and 2008.

No significant trend of the exceedances can be observed. Averaged over all monitoring sites, a decrease of 0.4 days per year was found between 1992 and 2008.

To reduce ozone levels, substantial reductions of emissions of the ozone precursor substances VOC and NO_x are necessary in Austria as well as in other countries in central Europe. NO_x emissions are currently above the NEC limits for 2010.

The target value for the protection of the vegetation (AOT40¹ of 18,000 g/(m.h)), averaged over five years) of Directive 2008/50/EG was exceeded at 60% of all monitoring sites in Austria between 2004 and 2008. The longterm objective for the protection of vegetation (AOT40 of 6,000 g/(m.h)) was exceeded at all stations save one, which is situated close to a highway due to NO titration.

(¹ AOT40: means the sum of the difference between hourly concentrations greater than 80 g/m (= 40 parts per billion) and 80 g/m over a given period using only the onehour values measured between 8.00 and 20.00 Central European Time (CET) each day.)

No significant trend of the AOT40 levels since 1992 can be observed. Averaged over all monitoring sites, an increase of 200 g/(m.h) per year has been found.

Information about the current ozone levels

Acidification can lead to longterm damage in the structure and functioning of ecosystems. To estimate the ecosystem area at risk, the Critical Loads concept was developed within the UNECE Convention on Longrange Transboundary Air Pollution. Critical Loads for acidification are projected to be exceeded at four out of 496 sites in 2010. This corresponds to about 0.6% of the overall modelled forest ecosystems. All exceedances occur in the northern part of Austria ("Bhmische Masse" which is characterised by a low buffering capacity of acidifying substances). The exceedances are caused by both sulphur and nitrogen deposition (Umweltbundesamt 2008).

Critical Loads: A quantitative estimate of an exposure to one or more pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according to present knowledge' (Nilsson and Grennfelt 1988).

Deposition of nitrogen can lead to eutrophication which changes the biodiversity of an ecosystem. Critical Loads for eutrophying nitrogen deposition are projected to be exceeded at about 94% of the forest area. The highest exceedances occur north of the Alps and in the eastern part of Austria, reflecting high nitrogen deposition in these areas (Figure 7).

For seminatural vegetation, Critical Loads are based on expert estimates. These empirical Critical Loads for eutrophying nitrogen for seminatural vegetation are exceeded at 31% of the ecosystem area. The percentage of exceedance per ecosystem is shown in Figure 8. Figure 9 shows the exceedance of empirical critical loads.

Information about the current number of exceedances of air quality limit values and thresholds 

Daily report on air quality  

Links & References