Exceedance of air quality standards

Transcription

1 Air quality in Europe (and particularly in the large urban areas) has improved in recent decades. However, it is estimated that in nearly all EU urban citizens were exposed to air pollution levels exceeding the (proposed) EU air quality standards set for the protection of human health. Although implementation of the Auto-Oil measures is expected to result in significant improvements, the outlook for shows that some 70 % of the EU urban population will still be exposed to PM 10 levels exceeding the limit values, some 20 % to NO 2 exceedances, and some 15 % to benzene exceedances. Figure 1 Urban population potentially exposed to exceedances of EU air quality standards set for the protection of human health. CO Benzene NO2 PM10 Other sources Traffic 0% 20% 40% 60% 80% 100% % of urban population potentially exposed Source: EEA, ETC/AQ (2001) Note: The figure indicates potential exposure as estimates are based on the assumption of exposure for a person permanently in ambient air (i.e. not taking into account the indoor exposure). Objective Meet EU air quality standards set for protection of human health (see Table 1). Definition Exceedances of (proposed) EU air quality standards for particulate matter (PM 10 ) 1, nitrogen dioxide (NO 2 ), benzene (C 6 H 12 ), ozone (O 3 ), lead (Pb) and carbon monoxide (CO). Population exposed to exceedances of (proposed) EU urban air quality standards. Note: The measured values available from the European air quality database AIRBASE were found to have insufficient spatial coverage and representativeness to allow the potential exposure of the urban population in the EU to air pollution to be estimated. Exceedances of limit values 1 PM 10 is the fraction of suspended particulate matter sampled with size-selecting device with a 50 % efficiency at an aerodynamic particle diameter of 10 micrometer. Version

2 were calculated using a model developed in the Auto-Oil II programme (EEA, ETC/AQ 2001). By combining calculated values and population data, an estimate was made of potential exposure, i.e. the exposure of people if they were in ambient air 24 hours a day. See under metadata for more explanation. Policy and targets The transport sector is a major source of air pollution, and the dominant source in urban areas, having overtaken the combustion of high-sulphur coal, oil and industrial combustion processes. Exposure to air pollution is associated with adverse health effects, most acute in children, asthmatics, and the elderly (WHO/EEA, 1997), and can damage vegetation (foliar injuries and reductions in yield and seed production) and materials (notably, the cultural heritage). Within the transport sector, road traffic is the most important contributor to urban air pollution. National and EU regulations aimed at automobile emission reductions (such as the introduction of catalytic converters or unleaded petrol) have resulted in considerably lower emissions per vehicle, but the continuous expansion of the vehicle fleet is partly offsetting these improvements (see Indicator 2). Community policies to curb air pollution from road traffic have been framed around the Auto-Oil I and II Programmes. Further development of policies is foreseen in the programme Clean Air for Europe. At the international level, various protocols under the Geneva Convention on Long Range Transboundary Air Pollution (CLRTAP) set emission reduction targets for specific pollutants in the form of National Emission Ceilings based on a cost-effectiveness analysis. The Commission has proposed similar National Emission Ceilings based on its acidification and ozone abatement strategy. The United Nations Framework Convention on Climate Change is also relevant since measures to reduce emissions of greenhouse gases from fuel consumption will at the same time reduce emissions of other pollutants. Several air quality limit values for ambient concentrations have been set to protect human health. Current EU legislation (the EC Framework Directive on Ambient Air Quality and management (CEC, 1996a) and related daughter Directives) is based on WHO-recommended threshold values. Table 1: Adopted or proposed EU Air Quality objectives set for the protection of human health pollutant averaging target no. of to be met reference period value exceedance SO2 1h 350 µg/m 3 < 25 times /30/EC SO2 24h 125 µg/m 3 < 4 times /30/EC NO2 1h 200 µg/m 3 < 19 times /30/EC NO2 year 40 µg/m 3 none /30/EC PM h 50 µg/m 3 < 8 times /30/EC PM10 1 year 20 µg/m 3 none /30/EC Lead year 0.5 µg/m 3 none /30/EC Ozone 8h 120 µg/m 3 < 26 days COM(2000) 613final 2 Benzene year 5 µg/m 3 none /69/EC CO 8h 10 mg/m 3 none /69/EC 1) For PM10 interim objectives have been set to be met : annual mean 40 µg/m3; 24 h average 50 µg/m3 not to be exceeded more then 35 days per year. 2) Common Position Version

3 Findings Figure 2: Urban population potentially exposed to exceedances of (proposed) EU urban air quality standards under a 'zero traffic' scenario (EU) - Results for the reference years and (assuming the Auto Oil II emission scenario) CO Benzene NO2 PM10 Other sources Traffic 0% 20% 40% 60% 80% 100% % of urban population potentially exposed Source: EEA, ETC/AQ (2001) Note: The figure indicates potential exposure as estimates are based on the assumption of exposure for a person permanently in ambient air (i.e. not taking into account the indoor exposure). Although air quality in Europe (and particularly in the large urban areas) has improved in recent decades, the model calculations suggest that in nearly all EU urban citizens may have been exposed to air pollution levels exceeding the limit values listed in Table 1 (Figure 1). About 90 % of the urban population experience exceedances of both the 24 h and annual average EU targets for particulate matter to be met in. Exposure to exceedances of NO 2, benzene and ozone was also frequent in ; this conclusion is confirmed by the available measurements (EEA, ETC/AQ 2001). Results from scenario calculations, assuming the baseline scenario of the Auto-Oil 2 study, suggest that exposure in will have decreased substantially (Figure 2). However, some 70 % of the EU urban population will still be exposed to PM 10 levels exceeding the limit values, some 20 % to NO 2 exceedances, and some 15 % to benzene exceedances. For CO and ozone, the figures are around zero. While the transport sector is an important source of many of the pollutants in Table 1, other sectors also contribute to air pollution. Figure 2 shows some comparative results, with and without the assumption of zero pollutant emissions from road transport in a given city. With this assumption, exceedances of threshold values for typical transport-related pollutants like NO 2, CO and benzene would decrease dramatically, but there would be less impact on PM 10 levels, most of which result from secondary (for instance ammonium sulphate and nitrate) and directly emitted particles transported over long distances. Version

4 Nitrogen dioxide (NO 2 ) Benzene Carbon monoxide (CO) Particulate matter (PM 10 ) Ozone The EU air quality limit values were exceeded in in most European cities. However, peak concentrations are decreasing. In most larger cities, average city background concentrations, representative of the urban area at large, exceeded EC limit values. From the limited monitoring data, the highest concentrations appear to occur in some southern European cities. In about half the urban population of the EU was exposed to benzene levels in excess of the EU limit value. The largest exceedances were found at street level and in car parks. Validation of the benzene calculations with measurements is difficult, partly because the scarcity of data (as submitted to the European database AIRBASE ) and partly because measurements are frequently made at stations near traffic routes whereas the calculations are intended to be representative of the overall urban environment. Nevertheless, there is reasonable agreement with measurements. Exceedances occur most often in the more southern countries. The highest contribution of traffic to total benzene emissions is also found in these countries. Urban air concentrations have clearly fallen during the past decade. Exceedances of the target (8-hour average of 10 mg/m 3 ) have been calculated for 11 cities (14 % of the total urban EU population in all the cities that were included in the modelling). Most exceedances were found in the southern Europe cities. The EU limit values (both for the annual and for the daily PM 10 concentrations) are frequently exceeded by a large margin. Data is currently insufficient to draw firm conclusions about emission trends. However, concentrations of total suspended particulates (TSP) and black smoke are generally decreasing. PM 10 concentrations are expected to remain well above limit values in most urban areas of EEA member countries in the coming decade. This suggests that more measures need to be taken to reduce human health risks significantly (CEC,1999c). Episodes of ozone exceedance occur over most of Europe every summer. The reduction in emissions of ozone precursors (NO x, NMVOC) achieved in the EU has not yet been sufficient to make a significant difference to the health risk. Threshold values set for the protection of human health and vegetation are frequently exceeded by a large margin (see e.g. de Leeuw et al. 2000). Large year-to-year fluctuations resulting from episodes of high ozone concentrations preclude clear conclusions on time trends. However, the limited monitoring data suggests that peak concentrations are decreasing slightly (de Leeuw, 2000). Despite projected further emission reductions, ozone concentrations are expected to exceed EC threshold values over all EEA member countries in the next decade (EMEP, 1999). By, north-western European areas are expected to comply with the proposed EU target value of less than 26 exceedance days per year as a long-term air quality objective (CEC, 2000). Lead Urban lead concentrations in the past decade have decreased. In 1990, 23 % of the EU urban population might have been exposed to ambient levels in excess of the limit value of 0.5 µg/m 3 annual average, as estimated from the cities covered by the calculations. Version

5 Future work Considerable work is underway both in the EU and in the CLRTAP to improve knowledge about particle emissions, and the contributions from various sectors to these emissions. Particles are being assessed in the integrated assessment framework previously used for underpinning the EU acidification and ground-level ozone abatement strategies, and the 1999 Gothenburg protocol of the CLRTAP. Extension of this framework to include urban air pollution is a priority. Particles and ozone are priority pollutants in the EC DG Environment Clean Air For Europe Programme that is currently being established. Meta data Results for this indicator were obtained using the Generalised Empirical Approach (GEA) developed for air quality evaluation in the second Auto-Oil Programme (AOP-II). (EEA, ETC/AQ 2001) The aim of the GEA is to estimate the size of the urban population living in cities within the European Union which are not in compliance with air quality objectives in future years and to estimate additional emission reductions needed to achieve compliance. In the GEA approach, simple model tools are used to calculateair quality in a relatively large number of cities in a consistent way. This allows for a generalisation of the results for the whole European Union. In the study, the air quality in about 200 urban agglomerations within the EU was calculated for a reference year ( or 1990) and for the, assuming the Auto Oil II Programme base-case scenarios. The parameter calculated was the urban background air pollution concentration, which is representative of the concentration in most of the urban area, with the exception of places under direct influence of emission sources, such as street traffic. The calculated urban background concentrations in the set of modelled cities were combined with urban population data to estimate the fraction of the urban population exposed to concentrations above agreed or proposed air quality standards. For the reference year, the calculated concentrations were compared with measured concentrations. For the year, the results were compared with the results of a detailed study for 10 cities using state-of-the-art models. 1. Data sources: CORINAIR, AIRBASE 2. Description of data: Emission data taken from CORINAIR (national totals, SNAP level 1); Future emissions () according to base case scenario developed in AOPII. Monitoring data used to validate the dispersion models is taken from AIRBASE. Meteorological data from ECMWF and/or DNMI original measure units: tonne/yr; ug/m3 3. Geographical coverage: EU15 4. Temporal coverage: annual; hourly 5. Methodology and frequency of data collection: Annually submitted data to Commission, EEA and EMEP 6. Methodology of data manipulation: model dispersion calculation using cq model, OFIS model and UAQAM model; see EEA, ETC/AQ 2001 Qualitative information 7. Strength and weakness (at data level): see EEA, ETC/AQ Reliability, accuracy, robustness, uncertainty (at data level): see EEA, ETC/AQ Further work required (for data level and indicator level): Version

6 References CEC 1996a Council Directive 96/92/EC on ambient air quality assessment and management CEC 1999c The Auto Oil II Programme. European Commission, Brussels. Available at CEC 1999a COM(1999) 125 final; see Council conclusions of June 2000, Common position on the proposed Directive on national emission ceilings for certain atmospheric pollutants. Council of the European Union. CEC 2000 COM(2000) 613final2 amended in Common Position De Leeuw FAAM, Sluijter RBJC, Bogman F. (2001) Air pollution by ozone in Europe in 1999 and summer EEA Topic Report to be published, European Environment Agency De Leeuw FAAM 2000 Trends in ground level ozone concentrations in the European Union. Environmental science and Policy, 3, EEA-ETC/AQ 2001 Air Quality in larger cities in the European Union, a contribution to the Auto Oil II Programme. To be published as EEA Topic Report, 2001 EMEP 1999 Transboundary photo-oxidants in Europe. EMEP summary report 2/99 EMEP/MSC- W, Oslo WHO/EEA 1997 Environment and Health. World Health organisation/european Environment Agency, EEA Environmental Monograph 2, Copenhagen, Denmark Version