2.2 Air quality assessment pursuant to the Regulation of the Government of the Czech Republic No. 350/2002 Coll.

The extent of air pollution is objectively determined by monitoring pollutants� concentrations in the ground layer of atmosphere within the network of measuring stations. Within air quality assessment there are compared mainly the recorded air pollution levels with the respective limit values, or with admissible exceedence frequencies of these limits which should not be further exceeded after the date in compliance with the legislation. On 1 June 2002 Clean Air Act No. 86/2002 Coll., amended later by 521/2002 Coll., 92/2004 Coll. and 186/2004 Coll., came into force, and on 14 August 2002 the Government Order No. 350/2002 Coll. setting forth limit values and procedures of monitoring, assessment, evaluation and management of air quality came into force. The new legislation fully reflects the requirements of the European Union set by the ambient air quality directives.

This part of the Yearbook presents air quality assessment in the year 2003 with regard to the requirements of the new Czech legislation. Pursuant to the Clean Air Act the assessment is aimed mainly at defining the areas with deteriorated air quality, with regard to health protection and the protection of ecosystems and vegetation respectively.

Air quality assessment pursuant to the new legislation reassumes the results and mainly methods developed within the research project VaV740/2/00 �Evaluation of the Czech Republic Readiness to Meet Air Quality Requirements of EU Directives and the LRTAP Convention� [9], especially in its stage aimed at the classification of the territory reflecting the requirements set by the newly introduced national legislation. The evaluation was based on the standards and requirements on air quality assessment set by the Council Directive 96/62/EC [10] on ambient air quality assessment and management and the follow-up Directive 99/30/EC [11] relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, PM₁₀ and lead in ambient air, Directive 2000/69/EC [12] of December 2000, setting up the limit values for carbon monoxide and benzene, and finally on the Directive 2002/3/EC [13] setting up the limit values for ozone. The Government Order introduces also the limit value for ammonia, arsenic, cadmium, nickel, mercury, benzo(a)pyrene and dustfall. Dustfall assessment cannot be carried out for the lack of data. Similarly, the assessment of air pollution caused by benzene, benzo(a)pyrene and primarily ammonia and mercury has faced the same problem so far.

The complete results of the solution of the project VaV/740/2/00 were uploaded on the CHMI websites.

The new air quality directives require that the member states should divide their territories into zones and agglomerations while the zones are understood as basic units for air quality management. The directives specify namely the requirements for the assessment – the classification of the zones with regard to air quality. The Clean Air Act covers this issue in par. 7 dealing with special air quality protection. Article 1 introduces the term �areas with deteriorated air quality�. These are areas with the exceedence of the values of one or more air pollution limits or of the target limit value for ozone, or the value of one or more limit values including the respective margins of tolerance. Special air quality protection is required in agglomerations, i.e. in inhabited areas with the population of at least 250 000, or the area with less inhabitants but where the density of population requires special measures on air quality protection and the necessity to assess and manage air quality in the area.

Within the project VaV740/2/00 the agglomerations were proposed pursuant to the Directive 96/62/EC. The proposal is based on the number of inhabitants and on the results of the long-term air quality assessment (Table 2.2.1). The Prague and Brno agglomerations represent the areas where air pollution is connected mainly with high density of population, in the Ostrava agglomeration, covering the cities of Ostrava, Karviná, Havířov, Český Těšín and Třinec, and in the Ústí nad Labem agglomeration, covering the belt of north-Bohemian industrial cities in the coal basin (Ústí nad Labem, Děčín, Teplice, Most, Chomutov, Litvínov, Klášterec nad Ohří and Kadaň) air pollution is influenced also by high concentration of industrial plants. Due to the delineation of agglomerations air quality assessment in these areas will be determined mainly on the basis of regular and quality measurements.

In the areas not included into the category of deteriorated air quality, i. e. in the areas where no limit values are exceeded, it is necessary to ensure the maintenance of good air quality. This corresponds with one of the basic principles of the Directive 96/62/EC, which requires that the once reached complying air quality continues to be maintained in the future.

For the areas with deteriorated air quality the Clean Air Act in its Article 6, par. 7 sets the obligation for the regional and local authorities to develop programs aimed at the improvement of air quality for those pollutants which show limit values and margins of tolerance exceedences (in case of ground-level ozone target air pollution limit values), with the aim to reach the limit values in the deadlines set in the implementing regulations. The definition of the areas in which air pollution limit values set by the Government Order are exceeded is a necessary prerequisite for the preparation of programs aimed at the improvement of air quality, or of the regulation rules at the regional and local levels in these areas.

In accordance with the generally accepted interpretation in the member countries, the areas delineation is primarily to be based on the administrative division of the country to allow the areas, as administrative units, to meet the requirements of the directives for air quality assessment, reporting to the Commission, and air quality management.

Tab. 2.2.1 Proposed agglomerations

2.2.1 Mapping air quality characteristics required by the legislation

The adopted legislation takes over general approaches of air quality assessment and potential exceedences of the set limit values in the zones from the Framework Directive 96/62/EC for air quality management with the aim to reach, in the set deadlines, air quality complying with the air pollution limit values and target air pollution limit values. The Directive specifies that in areas over the UAT, measurement is decisive for determining pollution levels. Pollution levels must be determined for the whole zone rather than covering the mere surroundings of the station. The problem of air quality assessment in zones – particularly identifying and locating areas within the zone in which limit values may be exceeded, based on station measurements – therefore becomes a problem of estimating (throughout the zone) the distribution of air quality; it consists in how to generalise �point� measurements, given the particular density of stations and an acceptable error of the estimate, to the entire zone under review. The spatial coverage of measurements can be increased by validation measurements. However, the ambient air quality directive and consequently, the national legislation, do not stipulate measurements any longer as the only tool for determining levels in a zone, and envisages – depending on pollution levels – the use of modelling techniques and expert estimates and their combinations. An advantage of modelling is that in comparison with point measurements it better reflects the coverage of the area under review; nevertheless, models are generally regarded as less accurate than measurements. Under modelling mainly causal dispersion and transport models are understood, including chemical transformations of the pollutants. An important role is played also by empirical, mathematical-statistical models of the estimate of time or spatial distribution of air pollution characteristics.

As part of regular air quality assessment, the Air Quality Information System has been using various combinations of measurements and modelling for creating fields of ambient air pollution characteristics, and these techniques are being further improved.

One of the important preconditions for creating fields of concentrations is a careful selection of the measuring stations included in the assessment, from the perspective of their use, classification and representativeness. Linear regression of the dependence of the two approaches (modelling and measurement) was applied when producing final information for map compilation in the assimilation of modelled and measured data, while a modified version of IDW, with the station�s weight and determination of its representative surroundings factored in, was applied to create the resulting fields. The basic approach to determine the degree of representativeness is station classification. Background stations (rural or urban background) with a high degree of representativeness (dozens of kilometres) are stations affected only by remote sources, while to describe local conditions also such stations exposed to traffic and industry are taken into account the least area of representativeness of which is directly affected by local sources.

The details of the mapping procedures of the respective air pollution characteristics for the pollutants set in the directives 99/30/EC (SO₂, suspended particles – PM₁₀ fraction, NO₂ and NO_x, lead), 2000/69/EC (CO and benzene) and 2002/3/EC (ozone) were published in the reports on the above project VaV740/2/00. Mapping procedures of air pollution characteristics of further substances required by the new legislation (cadmium, arsenic, nickel, mercury and benzo(a)pyrene), including further development of mapping air pollution characteristics of PM₁₀ and benzene were solved within the CHMI project VaV/740/3/02 �Integrated air quality assessment and management with regard to the daughter directives on heavy metals, PAHs, PM₁₀ and benzene�.

2.2.2 Air quality with regard to health protection limit values

In accordance with the EU legislative documents on air quality the Czech legislation sets the limit values aimed at health protection derived from the WHO recommendation. The national legislation requires to monitor and assess the following pollutants, as substances manifesting evident harmful effects on the health of the population, with regard to the health protection limit values:

1. sulphur dioxide
2. suspended particles - PM₁₀ fraction
3. nitrogen dioxide
4. lead
5. carbon monoxide
6. benzene
7. ozone
8. cadmium
9. arsenic
10. nickel
11. mercury
12. benzo(a)pyrene
13. ammonia.

The survey of the limit values, margins of tolerance for the protection of health, and UAT and LAT according to the Government Ordershows the Table 2.2.2. These limit values, including the UAT and LAT have been set by the legislation as the levels for air quality assessment. The maps and charts presented below use the indication of the respective limit values as shown in Table 2.2.2.

The following assessment of individual pollutants relevant for health protection is presented in the order corresponding with the above list. It is documented mainly by the tables showing the stations with the highest values of air pollution characteristics required by the legislation for the given pollutants. The shades of the background in the tables indicate:

If the number of stations where the limit value, or the limit value incl. the margin of tolerance, was exceeded, is lower than 10, 10 stations with the highest values of the respective air pollution characteristics are presented. Further, maps depicting the development of the respective characteristics in the period 1992–2003 are presented. The 2003 exceedence of the limit value increased by the margin of tolerance is marked with red names of the stations.

If in 2003 any characteristic of the respective pollutant was exceeded, also maps depicting the spatial distribution of the characteristic are presented. These maps show also the stations classified according to their type and marked with colour symbols in correspondence with the classes of the levels measured at the presented stations.

For the stations and air pollution characteristics, where the number of exceedences incl. the margin of tolerance was higher than it is allowed, the courses of 24-hour or hourly concentrations in 2003 are presented for the indication of the period of the year during which the limit values were exceeded.

In 2003 this chapter is concluded by two graphs showing the trends of the characteristics of selected pollutants in agglomerations and in the Czech Republic in the period of 1994–2003.

Tab. 2.2.2 The limit values for the protection of health pursuant to the Government Order No. 350/2002 Coll. setting forth limit values and procedures of monitoring, assessment, evaluation and management of air quality

2.2.2.1 Sulphur dioxide

The 2003 situation of air pollution caused by SO₂ with regard to the limit values set by the new legislation is documented by the Tables 2.2.3, 2.2.4 and Figs. 2.2.1, 2.2.2, 2.2.3, 2.2.4. It is evident from Figs. 2.2.1 and 2.2.4 that in 2003 the set limit value for 24-hour SO₂ concentration 125 μg.m^-3 was exceeded more than 3x at the Public Health Service station Úštěk. The annual SO₂ limit value was not exceeded at any station in 2003. Similarly, no station reported the exceedence of the allowed number of exceedences of hourly SO₂ concentrations (500 μg.m^-3). The highest number of exceedences of the hourly limit value was recorded at Nová Víska u Domašína (3x), Měděnec (2x) and Horní Halže (2x) stations.

The map diagrams in Fig. 2.2.1 show the distinct improvement of air quality resulting from the significant decrease of SO₂ concentrations documented by the marked decline of the 4^th highest 24-hour SO₂ concentration at all stations after the year 1997. In 2003 there occurred very slight increase in SO₂ pollution in several areas of the Czech Republic caused probably by more intensive solid fuels burning.

Figs. 2.2.3 and mainly 2.2.4 should, in compliance with the requirements of the Framework Directive, document the limit values exceedence episodes. Fig. 2.2.4 confirms the last year�s situation in the environs of the Public Health Service station Úštěk. In 2003 the 24-hour concentrations exceeded the set limit value of 125 μg.m^-3 in 4 cases.

Fig. 2.2.2, presenting the spatial distribution of the 4^th highest 24-hour SO₂ concentrations, and the Tables 2.2.2 and 2.2.4 show that in 2003 the air pollution caused by SO₂ did not exceed, with the exception of the Public Health Service station Úštěk, where local influence can be expected, the limit values for the protection of health. With the above exception the pollution caused by SO₂ is not the reason to list any part of the territory among the areas with deteriorated air quality.

Tab. 2.2.3 Stations with the highest numbers of exceedences of the hourly limit value (pLV) and hourly limit value including the margin of tolerance (pLV+MT) of SO₂

Tab. 2.2.4 Stations with the highest numbers of exceedences of the 24-hour limit value (pLV) of SO₂

Tab. 2.2.5 Stations with the highest values of annual average concentrations of SO₂

Fig. 2.2.1   4^th highest 24-hour concentrations and annual average concentrations of SO₂ in 1992–2003 at selected stations

Fig. 2.2.2 Field of the 4^th highest 24-hour concentration of SO₂ in 2003

Fig. 2.2.3 Stations with the highest hourly concentrations of SO₂ in 2003

Fig. 2.2.4 Stations with the highest 24-hour concentrations of SO₂ in 2003

2.2.2.2 Suspended particles, PM₁₀ fraction

Air pollution caused by PM₁₀, as shown in the Tables 2.2.6 and 2.2.7, similarly as in Fig. 2.2.5, remains one of the main problems of air quality assurance with regard to the requirements and deadlines of the new legislation and the respective EU directive. Fig. 2.2.5 shows the increasing trend of PM₁₀ pollution at almost all stations in the Czech Republic which started in 2001.

The limit value of 24-hour PM₁₀ concentration increased by the margin of tolerance was exceeded more than 35x in 2003, and namely at the stations in the Moravian-Silesian Region: Havířov, Český Těšín, Bohumín, Věřňovice, Ostrava-Přívoz, Ostrava-Fifejdy, Karviná and Orlová, and at the stations in the following regions: Central Bohemian Region (Kladno-Švermov and Mladá Boleslav); Prague Region (Smíchov, nám. Republiky, Riegrovy sady and Počernická); Ústí nad Labem Region (Ústí n.L.-Město and Chomutov). Of the total number of 92 stations at which PM₁₀ measurements are carried out, 68 stations reported exceedences of 24-hour PM₁₀ limit value in more than is the tolerated number of exceedences, and 55 of them reported also exceedences of the limit value including the margins of tolerance.

The annual PM₁₀ limit value was exceeded at 41 stations, 30 of them exceeded also the margin of tolerance.

The number of stations at which both above air pollution characteristics of PM₁₀ fraction exceeded the limit values and the margin of tolerance increased in 2003.

Figs. 2.2.6 and 2.2.7 show that PM₁₀ limit value exceedences are significant for listing the basic administrative units among the areas with deteriorated air quality. Limit values for 24-hour PM₁₀ concentrations were exceeded more than 35x mainly in Moravian-Silesian, Ústí nad Labem, Central Bohemian and Olomouc Regions and in Prague also in 2003. Fig. 2.2.6 shows quite evidently that in the towns where the PM₁₀ measurements are carried out the result concentrations of this pollutant are above the limit value. However, it can be admitted that in the towns without PM₁₀ measurements the concentrations exceed the limit value as well. The model application is difficult in this case as the model calculations include only the emissions from primary sources. The significant share in PM₁₀ pollution is contributed by secondary particles and re-suspended particles, not included in the emissions from the primary sources.

The areas where PM₁₀ concentrations exceed the respective limit values represent almost 11.5 % of the territory of the Czech Republic with more than 37 % of the total population. The shown values confirm the increasing trend in air pollution caused by PM₁₀ which started in 2001 and was emphasized in the dry year of 2003 with very low precipitation.

The courses of 24-hour concentrations in 2003 at the stations, where the limit value including the margin of tolerance was exceeded, are shown in Fig. 2.2.8. The selection of 11 stations with the greatest number of LV+ MT exceedences includes 8 stations from the Moravian-Silesian Region. The figure also shows the annual course of the average daily temperature in 2 meters above the ground (T2m) and the average daily wind velocities (WV). In the 2003 results there is a significant opposite seasonal course between PM₁₀ concentration and the temperature. Wind velocity above 3 m.s^-1 also results in the decline of PM₁₀ concentrations.

Tab. 2.2.6 Stations with the highest numbers of exceedences of the 24-hour limit value of PM₁₀

Tab. 2.2.7 Stations with the highest values of annual average concentrations of PM₁₀

Fig. 2.2.5  36^th highest 24-hour concentrations and annual average concentrations of PM₁₀ in 1994–2003 at selected stations

Fig. 2.2.6 Field of the 36^th highest 24-hour concentration of PM₁₀ in 2003

Fig. 2.2.7 Field of annual average concentration of PM₁₀ in 2003

Fig. 2.2.8 Stations with the highest exceedence of LV+MT for 24-hour concentrations of PM₁₀ in 2003

2.2.2.3 Nitrogen dioxide

The exceedence of annual limit values for NO₂ occurred only in limited number of localities exposed to traffic in agglomerations and large cities. Of the total number of 109 stations at which NO₂ was monitored in 2003 the annual limit value of 40 μg.m^-3 was exceeded at the station in Beroun and at 7 stations in Prague (Mlynářka, Vršovice, Smíchov, nám. Republiky, Počernická, Braník and Vysočany) and at the Šumperk station. The margin of tolerance was exceeded at the Beroun station.

Hourly concentrations of NO₂ (Table 2.2.8) do not exceed the allowed exceedence frequency at any station. In 2003 the highest value of the 19^th maximum hourly NO₂ concentration (296 μg.m^-3) was recorded at the station Plzeň-Slovany, Beroun (248 μg.m^-3) and Prague 10-Počernická (233 μg.m^-3).

In 2003 the NO₂ annual limit value and the margin of tolerance were exceeded at the Beroun station (63 μg.m^-3). The annual NO₂ limit value is almost regularly exceeded mainly in Prague at the stations monitoring the effects of traffic on urban environment (Prague 5-Mlynářka, Prague 1-nám. Republiky, Prague 10-Vršovice, Prague 5-Smíchov, Prague 10-Počernická and Prague 4-Braník, Table 2.2.9).

At most stations presented in Fig. 2.2.9 both the annual average concentration and the 19^th highest hourly NO₂ concentration had a moderately declining trend until 2001. In 2002 this trend stopped and in 2003 there was a slight increase of NO₂ pollution at most localities, more significant at the traffic stations. The slight increase of NO₂ concentrations was caused by rising fuel sales, and, consequently, by higher traffic emissions.

The field of annual average NO₂ concentration (Fig. 2.2.10) shows that there was a slight percentage increase, especially in the interval 26–40 μg.m^-3.

Fig. 2.2.11 presents the courses of hourly concentrations in 2003 showing the limit exceedences in the respective part of the year. The AMS Prague 2-Legerova, established in August 2003 as a traffic �hotspot� station monitoring the communication with heavy traffic, showed the exceedence of the limit value in 19 cases.

Tab. 2.2.8 Stations with the highest values of the 19^th and maximum hourly concentrations of NO₂

Tab. 2.2.9 Stations with the highest values of annual average concentrations of NO₂

Fig. 2.2.9 19^th highest hourly concentrations and annual average concentrations of NO₂ in 1992–2003 at selected stations

Fig. 2.2.10 Field of annual average concentration of NO₂ in 2003

Fig. 2.2.11 Stations with the highest hourly concentrations of NO₂ in 2003

2.2.2.4 Lead

Most lead contained in the atmosphere result from anthropogenic emissions caused by high-temperature processes, primarily the burning of fossil fuels, production of iron and steel and metallurgy of non-ferrous metals. Means of transport using leaded petrol represent a very significant source of anthropogenic emissions. In the natural processes lead is released through weathering of rocks and volcanic activity [14].

Airborne lead occurs in the form of fine particles with frequency particle size distribution characterized by the average aerodynamic diameter lower than 1 μm.

The long-term exposure to lead results in harmful impacts on haem biosynthesis, nervous system and blood pressure in humans. The evidence for carcinogenic potential of lead and its compounds in humans is inadequate [14, 15].

None of the total number of 59 stations which submitted sufficient data for the calculation of valid annual average in 2003 exceeded the set limit value. The highest annual average concentration was reached at the station Beroun-Zavadilka, and namely 73.8 ng.m^-3. Table 2.2.10 shows that lead concentrations at all stations are below the limit value and do not even reach the LAT (250 ng. m^-3). It is apparent from Fig. 2.2.12 that lead levels at the majority of stations do not reach the limit value in the long terms. Courses of 7/14-day average concentrations of lead at selected stations are presented Fig. 2.2.13.

Tab. 2.2.10 Stations with the highest values of annual average concentrations of lead in the ambient air

Fig. 2.2.12 Annual average concentrations of lead in the ambient air in 1992–2003 at selected stations

Fig. 2.2.13 7/14-day average concentrations of lead in the ambient air at selected stations in 2003

2.2.2.5 Carbon monoxide

The insufficient burning of fossil fuels may be an anthropogenic source of air pollution caused by carbon monoxide. These processes occur mainly in transport and in stationary sources, namely household heating.

In 2003, data for the calculation of the valid annual average of CO concentration were obtained from 42 stations. Maximum 8-hour moving averages of carbon monoxide (Table 2.2.11 and Figs. 2.2.14 and 2.2.15) do not exceed the limit values, with the exception of 2 Public Health Service stations: Prague 5-Svornosti, at which even the limit value incl. the margin of tolerance (LV+MT) was exceeded, and Prague 8-Sokolovská. With the exception of further two Public Health Service stations the maximum daily 8-hour moving average at the remaining stations did not reach the LAT.

Tab. 2.2.11 Stations with the highest values of maximum 8-hour moving average concentrations of CO

Fig. 2.2.14 Maximum 8-hour moving average concentrations of CO in 1994–2003 at selected stations

Fig. 2.2.15 Stations with the highest values of maximum 8-hour moving average concentrations of CO in 2003

2.2.2.6 Benzene

With the increasing intensity of road transport the monitoring of air pollution caused by aromatic hydrocarbons is becoming relevant. The decisive source of atmospheric emissions of aromatic hydrocarbons – and namely of benzene and its alkyl derivates – are above all exhaust gases of petrol motor vehicles. Another source are loss evaporative emissions produced during petrol handling, storing and distribution. Mobile sources emissions account for approx. 85 % of total aromatic hydrocarbons emissions, while the prevailing share is represented by exhaust emissions. It is estimated that the remaining 15 % of emissions come from stationary sources. Many of these are related to industries producing aromatic hydrocarbons and those industries that use these compounds to produce other chemicals.

The obtained data illustrate that benzene level in petrol is about 1.5 % while diesel fuels contain relatively insignificant levels of benzene. Exhaust benzene is produced primarily by unburned benzene from fuels. Non-benzene aromatics in the fuels can cause 70 to 80 % of the exhaust benzene formed. Some benzene also forms from engine combustion of non-aromatic fuel hydrocarbons. The most significant adverse effects from exposure to benzene are haematotoxicity and carcinogenicity [16].

Recent assessment based on measurement results indicate that limit values of benzene concentrations are exceeded in Ostrava (Fig. 2.2.16), mainly as the result of emissions from coking plants. The situation of the year 2003 is characterized in the Table 2.2.12. Of the total number of 17 stations monitoring benzene concentrations in 2003 the limit value was exceeded only at two stations in Ostrava (Ostrava-Přívoz and Ostrava-Přívoz-HS). The valid annual average was calculated for six stations only due to the fact that the measurements pursuant to the legislation were started only in 2003 at several stations.

Tab. 2.2.12 Stations with the highest values of annual average concentrations of benzene

Fig. 2.2.16 Annual average concentrations of benzene in 1999–2003 at selected stations

Fig. 2.2.17 24-hour concentrations at the stations with the highest annual benzene concentrations in 2003

2.2.2.7 Ground-level ozone

Ground-level ozone is formed under the influence of solar radiation during complex photochemical reactions mainly between nitrogen oxides, VOCs (mainly hydrocarbons) and other components of the atmosphere. Ground-level ozone is a secondary pollutant as its primary emitting from anthropogenic air pollution sources is not substantial.

In 2003 the air pollution target value was exceeded at 43 stations, out of 53 stations which submitted valid data (Table 2.2.13). High ozone concentrations and limit exceedences at most station were recorded as a result of long period with high temperatures, intensive solar radiation and draught in the 2003 summer period. This exceptional situation was observed practically in the whole of Europe.

Map diagram in Fig. 2.2.18 shows the 26^th highest value of maximum 8-hour moving average of ozone concentrations (three-year average) in 1992–2003.

The target air pollution limit value for the protection of health was exceeded in 94 % of the Czech Republic�s territory in 2003 (Fig. 2.2.19).

Table 2.2.13 presents the stations with the highest values of maximum daily 8-hour moving average ozone concentrations in three-year average as required by the legislation. Besides, these values are shown also for the respective calendar years (2001, 2002 and 2003). The comparison of the values shows that the highest values were reached in 2003 (considering the meteorological conditions).

Table 2.2.14 presents the number of hours of the ozone alert threshold exceedence (180 μg.m^-3) at selected AIM stations in the period of 1992–2003.

Tab. 2.2.13 Stations with the highest values of maximum daily 8-hour moving average concentrations of ozone

Tab. 2.2.14 Number of hours of the ozone alert threshold exceedence (180 μg.m^-3) per year at selected AIM stations, 1992–2003

Fig. 2.2.18 26^th highest values of maximum 8-hour moving average of ozone concentrations (three-year average) in 1992–2003 at selected stations

Fig. 2.2.19 Field of the 26^th highest maximum daily 8-hour moving average of ozone concentration in three-year average, 2001–2003

Fig. 2.2.20 Stations with the highest values of maximum daily 8-hour moving average concentrations of ozone in 2001-2003

2.2.2.8 Cadmium

Globally, the natural sources of cadmium represent about 10 % of which 50 % are caused by volcanic activity and 90 % by anthropogenic sources (mainly iron and steel production, metallurgy of non-ferrous metals, refuse incineration and fossil fuels combustion (brown coal, hard coal and heavy fuel oils) [17]. Emission from transport are less significant.

Cadmium is bound mainly to the fine particles (aerodynamic diameter up to 2.5 μm), with higher risk of negative effects on human health. Almost all cadmium is bound to particles up to 10 μm, while the minimum amount of cadmium is found in particles with diameter above 10 μm.

The kidney is the critical organ with respect to long-term exposure to cadmium. Its carcinogenic effects are evident in experimental animals and there has been limited evidence in humans so far [15, 17].

In 2003, the limit value 5 ng.m^-3 as the annual average concentration was not exceeded at any station of the total number o 83 (16 CHMI and 67 Public Health Service, Fig. 2.2.21).

The stations Tanvald and Souš with long-term increased cadmium concentrations did not submit sufficient data in 2003 for the calculation of the valid annual average. The expertise estimate based on the measured data, however, shows high probability of the limit value exceedence at Souš also in 2003. The 2003 cadmium concentration courses (daily or 14-day, depending on the measuring cycle at selected stations) are shown in Fig. 2.2.23. The courses at the stations HS Příbram, Ostrava-fak. nemocnice and Ostrava-Poruba IV are not included as their values remained below the margin of detection during the whole monitored period.

Tab. 2.2.15 Stations with the highest values of annual average concentrations of cadmium in the ambient air

Fig. 2.2.21 Annual average concentrations of cadmium in the ambient air in 1992–2003 at selected stations

Fig. 2.2.22 Field of annual average concentration of cadmium in the ambient air in 2003

Fig. 2.2.23 1/14-day average concentrations of cadmium in the ambient air at selected stations in 2003

2.2.2.9 Arsenic

Arsenic occurs in many forms of inorganic and organic compounds. The natural sources of arsenic represent about 25 % of the total emissions [17] and they include mainly volcanic activity; emissions released from vegetation are less significant. Anthropogenic sources include mainly combustion processes (brown coal, hard coal and heavy fuel oils), iron and steel industry and production of copper and zinc.

Arsenic occurs largely in fine fractions (aerodynamic diameter up to 2.5 μm), which can be transported over long distances and can penetrate deeply into the respiratory system. Almost all arsenic is bound to particles with aerodynamic diameter up to 10 μm [17].

Inorganic arsenic can cause acute, subacute or chronic effects (local or affecting the whole organism). Lung cancer can be considered the critical effect following inhalation exposure [15, 17].

Of the total number of 83 (1 CHMI and 67 Public Health Service) stations which submitted valid data for 2003 the limit value was exceeded at four stations (Ostrava-přívoz HS, Kladno-Dubí, Ostrava fak. nemocnice and Litoměřice-OHS, see Table 2.2.16).

The courses of short-term (1/14-day) average arsenic concentrations (Fig. 2.2.26) show, even more distinctively than in lead, the seasonal character of the short-time arsenic concentrations in the ambient air and confirm the significant arsenic contribution from the burning of fossil fuels, especially in the environs of the presented stations.

Tab. 2.2.16 Stations with the highest values of annual average concentrations of arsenic in the ambient air

Fig. 2.2.24 Annual average concentrations of arsenic in the ambient air in 1992–2003 at selected stations

Fig. 2.2.25 Field of annual average concentration of arsenic in the ambient air in 2003

Fig. 2.2.26 1/14-day average concentrations of arsenic in the ambient air at selected stations in 2003

2.2.2.10 Nickel

Nickel is the fifth most abundant element of the earth core, though in the earth crust its percentage share is lower.

Globally, 26 % of nickel is released from natural sources (continental dust and volcanic activity). The main anthropogenic sources include combustion of heavy fuel oils, mining of nickel-containing ores and nickel refinement, refuse incineration and iron and steel production.

Nickel occurs in the atmospheric aerosol in several chemical compounds which differ by its toxicity for human health and ecosystems.

Nickel is found in particles with aerodynamic diameter ≥ 10 μm which quickly settle in the vicinity of the source. The size of the remaining nickel particles is < 10 μm and they can be transported over long distances [17].

The health effects include allergic dermatitis and there is evidence of nickel carcinogenicity for humans [15, 17].

None of the total number of 38 stations (5 CHMI and 33 HS) from which data for 2003 were obtained, exceeded the set limit value. The highest valid annual average concentration was measured at the station Most-OHS (11.4 ng.m^-3).

The reason of the major improvement of the situation as compared to the preceding year, when 10 Public Health Service stations reported LV + MT exceedences, can be explained by upgrading the control system of the quality of measurements which resulted in better quality of the measured data at several Public Health Service stations.

Tab. 2.2.17 Stations with the highest values of annual average concentrations of nickel in the ambient air

Fig. 2.2.27 Annual average concentrations of nickel in the ambient air in 1992–2003 at selected stations

Fig. 2.2.28 1/14-day average concentrations of nickel in the ambient air at selected stations in 2003

2.2.2.11 Mercury

Main anthropogenic sources of mercury include combustion of fossil fuels, chlor-alkali production, metallurgy, cement production and refuse incineration. Mercury and its compounds are used in paint industry, battery production, measuring and control instruments (thermometers) [18].

Globally, anthropogenic emissions represent about 40 % of the total emissions. The natural sources include mercury evasion from aquatic ecosystems and vegetation, volcanic activity and de-gassing from mercury-rich minerals. It is estimated that in Europe 60 % of mercury is emitted in the form of elemental vapour Hg0, 30 % as divalent mercury (Hg (II)), and only 10 % as particulate phase mercury (H(p)). Most emission from natural sources are in gaseous form Hg0 [18].

Studies of occupationally exposed humans have shown adverse effects on the central nervous system and kidneys at high mercury vapour levels [18]. The increased concentration in the ambient air results in higher atmospheric deposition on top water layers and, consequently, in higher methylmercury concentrations in freshwater fish and its accumulation in food chains. [15, 18].

In 2003 the CHMI ISKO database received data on mercury concentrations from the CHMI station Ústí nad Labem-město and from 5 Public Health Service stations. These stations, however, have not the sufficient number of measurements for the valid annual average (with the exception of the Karviná-OHS station). The annual average mercury concentration in the ambient air at all these stations did not even reach the lower assessment threshold (LAT).

Tab. 2.2.18 Stations with the highest values of annual average concentrations of mercury in the ambient air

2.2.2.12 Benzo(a)pyrene

The natural background level of benzo(a)pyrene is almost zero with the exception of wildfires [15]. The cause of the presence of this main representative of polyaromatic hydrocarbons (PAHs) in the ambient air is, similarly as in other PAHs the insufficient burning of fossil fuels both in stationary and mobile sources, and also some technologies, as coke and iron production. Stationary sources are represented mainly by local heating. Mobile sources are represented mainly by diesel motors. Benzo(a)pyrene as well as several other PAHs are classified as proven human carcinogens [15, 19].

In 2003 benzo(a)pyren was monitored at 13 stations (10 HS and 3 CHMI) of which 5 stations (in Ostrava, Karviná, Prague, Ústí nad Labem, Hradec Králové) report regular and long-term exceedences of the set limit values (Fig. 2.2.29). There has been even an alarming increase of the annual average concentrations in several recent years. In 2003 the limit value was exceeded at 8 stations: in Ostrava, Karviná, Prague, Ústí nad Labem, Teplice and Hradec Králové). The limit value of the annual concentration was reached at Public Health Service station in Žďár nad Sázavou (Table 2.2.19).

The field of annual average benzo(a)pyrene concentrations (Fig. 2.2.30) prepared with the use of combination of emission dispersion models and the measured concentrations illustrate the significant contribution of this component in the delineation of the areas with deteriorated air quality. The areas where the limit values were exceeded represent more than 3 % of the state�s territory with about 20 % of the population.

However, it is necessary to consider that the estimates of the fields of annual average benzo(a)pyrene concentrations bear the greatest uncertainties which result both from insufficient measurement density and from uncertainties given by dispersion modelling of PAHs emissions; PAHs emission inventories represent the largest source of uncertainties.

Tab. 2.2.19 Stations with the highest values of annual average concentrations of benzo(a)pyrene

Fig. 2.2.29 Annual average concentrations of benzo(a)pyrene in 1997–2003 at selected stations

Fig. 2.2.30 Field of annual average concentration of benzo(a)pyrene in the ambient air in 2003

Fig. 2.2.31 24-hour concentrations at the stations with the highest annual concentrations of benzo(a)pyrene in 2003

2.2.2.13 Ammonia

Major part of ammonia emitted in the ambient air is created by disintegration of nitrogenous organic materials from domestic animals breeding. The remaining amount us emitted through combustion processes or production of fertilizers. It is apparent that ammonia emissions in the ambient air are contributed by vehicles (formation of ammonia in catalytic convertors). Ammonia has irritating effects on eyes, skin and respiratory system. Chronic exposure to increased concentrations can cause headache and vomiting [20]. Quite significant are ammonia odour annoyance impacts on the population.

Ammonia monitoring is so far limited to 2 stations only (1 Public Health Service and 1 CHMI station). The measured values remained well below the limit value. The highest daily value was measured at the station Lovosice-MÚ (40 μg.m^-3) which is exactly the value of LAT.

Tab. 2.2.20 Stations with the highest values of daily average concentrations of ammonia in the ambient air

Fig. 2.2.32 shows the trends of SO₂, PM₁₀, NO₂ and O₃ annual air pollution characteristics in the Czech Republic for the period of 1994–2003 (PM₁₀ since 1995). Up to the year 2000 the trend of air pollution caused by SO₂, PM₁₀ and NO₂ was decreasing in the whole Czech Republic. In the SO₂ and PM₁₀ concentrations the decline was very steep up to the year 1999. In 2001 the decreasing trend was interrupted and, on the contrary, a slight increase of SO₂ and NO₂ concentrations and a significant increase of PM₁₀ concentrations occurred. In O₃ there is an apparent decreasing trend up to 1997. In 1998–2002 the O₃ concentrations stagnated. In 2003 the measured values increased to the levels measured in 1994.

Fig 2.2.33 shows the trends of SO₂, PM₁₀ and NO₂ annual air pollution characteristics in 1994–2003 (PM₁₀ since 1996) for the following agglomerations: Prague, Ústí n. L., Ostrava and Brno. Up to 1999 there was a significant decreasing trend in SO₂ and PM₁₀ concentrations in the agglomerations, the NO₂ concentrations decreased only slightly. In 2001 the decreasing trend was interrupted and, on the contrary, the SO₂ and NO₂ concentrations slightly increased and PM₁₀ concentrations increased significantly, mainly in the Ostrava agglomeration. The SO₂ concentrations have not reached the limit value since 1998.

Fig. 2.2.32 Trends of SO₂, PM₁₀, NO₂ and O₃ annual characteristics in the Czech Republic, 1994–2003

Fig. 2.2.33 Trends of SO₂, PM₁₀ and NO₂ annual characteristics in agglomerations, 1994–2003

2.2.3 Areas with deteriorated air quality with regard to health protection

To delineate zones and agglomerations with deteriorated air quality in line with the new Clean Air Act exceedences of annual average concentrations of SO₂, PM₁₀, NO₂, lead, benzene, benzo(a)pyrene, cadmium, arsenic, nickel, mercury and ammonia were assessed for each station in accordance with the limit values and margins of tolerance set by the respective legislation. Frequencies of exceedence of daily limit values for PM₁₀ and SO₂ were calculated, as also those of exceedence of hourly limit values of SO₂ and NO₂ and frequencies of exceedence of 8-hour limit values of CO and ozone.

The above mapping procedures were used for the preparation of the maps of spatial distribution of the respective air pollution characteristics (Figs. 2.2.2, 2.2.6, 2.2.7, 2.2.10, 2.2.19, 2.2.22, 2.2.25 and 2.2. 30) presented in the previous subchapters. Areas with the values of air pollution characteristics higher than the respective limit values (areas marked in red or violet) delineate the areas with deteriorated air quality. Table 2.2.21 brings the overview of areas (listed according to regions and districts) in which the limit value for the protection of health was exceeded in 2003 based on the results of mapping air pollution characteristics distribution. The exceedence percentage in the respective territory is also presented. Table 2.2.22 summarises the areas of exceedences of health protection limit values including the margins of tolerance in 2003. The tables show the per cent of exceedence of the respective limit values in the given territory for individual components and air pollution characteristics and summarize the areas in which at least one limit value of the given components was exceeded. The percentages of exceedences presented in the overview in Table 2.2.21 correspond to the percentages of the territories of the given administrative unit in which at least one air pollution limit value of the set of limit values for the protection of health was exceeded. The map in Fig. 2.2.34 depicts the delineation of areas/basic administrative units with deteriorated air quality with regard to the limit values for the protection of health, excluding ozone) in 2003.

Table 2.2.23 shows the 2003 exceedence of the target limit value for ozone for the protection of health in the regions and districts of the Czech Republic and the share (%) of the respective territory. Ozone is presented separately, as it is evident that the measures aimed at the decrease of ozone concentrations exceeding the target limit value or the long-term air pollution targets, should be taken at the regional and national level. The areas with deteriorated air quality with regard to the target limit value for the protection of health are presented in the map (Fig. 2.2.19).

The map in Fig. 2.2.35 presents the areas/administrative units with deteriorated air quality with regard to health protection limit values incl. ozone.

Tab. 2.2.21 LV exceedences in the regions and districts of the Czech Republic, % of the area of the administrative unit, 2003

Tab. 2.2.22 LV+MT exceedences in the regions and districts of the Czech Republic, % of the area of the administrative unit, 2003

Tab. 2.2.23 Target ozone limit value exceedences for the protection of health in the regions and districts of the Czech Republic, % of the area of the administrative unit, 2003

Fig. 2.2.34 Areas/administrative units with deteriorated air quality with regard to health protection limit values, ozone excluded, 2003

Fig. 2.2.35 Areas/administrative units with deteriorated air quality with regard to health protection limit values incl. ozone, 2003

2.2.4 Air quality with regard to the limit values for the protection of ecosystems and vegetation

Besides the limit values for the protection of health the new national legislation introduces, in compliance with EU Directives, also the limit values for the protection of ecosystems and vegetation. The survey of the limits is presented in the Table 2.2.24.

Tab. 2.2.24 The limit values for the protection of ecosystems and vegetation pursuant to the Government Order No. 350/2002 Coll. setting forth limit values and procedures of monitoring, assessment, evaluation and management of air quality

The above territories are highlighted in the maps and specified in the legend. The maps do not cover the proposed (not declared yet) protected landscape areas.

2.2.4.1 Sulphur dioxide

The results of air pollution monitoring with regard to the limit value for the protection of ecosystems is shown in the Table 2.2.25 and in Figs. 2.2.36 and 2.2.37. Of the total number of 27 stations classified as rural – EKO (stations in the EKO zone meet at least one of the above a), b), c) condition), which supplied data valid for the year 2003, only 1 station reported the exceedence of the limit value for annual average concentration. No EKO station reported the limit value exceedences for the 2003/2004 winter average concentration (Table 2.2.25).

Fig. 2.2.36 demonstrates the significant improvement of air quality with regard to sulphur dioxide after 1997 in connection with coming into force of the Act No. 309/1991 Coll. and meeting the set emission limit values by the end of 1998. Most rural stations recorded slight decline in SO₂ pollution in the 2003/2004 winter average.

The map in Fig. 2.2.37 shows that in 2003 exceedences of the limit value occurred only in the northern part of the Karviná district, which is not included within the defined territories for the protection of ecosystems and vegetation, further in very small parts of the Krušné hory Mts. and České středohoří Mts., where the limit value exceedences do not reach even 0.01 % of the area of the defined territories for the protection of ecosystems and vegetation.

Tab. 2.2.25 Stations with the highest values of winter averages of SO₂ concentrations at rural stations, 2003/2004

Fig. 2.2.36 Winter average concentrations of SO₂ in 1992/1993–2003/2004 at selected stations

Fig. 2.2.37 Field of average concentration of SO₂ in the winter period 2003/2004

2.2.4.2 Nitrogen oxides

Table 2.2.26 and Figs. 2.2.38 and 2.2.39 present the situation of ambient air pollution caused by NO_x with regard to vegetation protection. In 2003 the annual NO_x limit (30 μg.m^-3) was not exceeded at any station classified as rural – EKO.

In 2003 very slight increase of annual average NO_x concentration occurred at most rural stations (Fig. 2.2.38). The slight increase in NO_x concentrations in the Czech Republic was caused by higher emissions from transport.

As it is evident from the map in Fig. 2.2.39, in very limited localites of the territory defined by the Government Order on the protection of vegetation, less than 0.4 % of the area of the defined territory recorded the exceedence of the respective NO_x limit values for the protection of ecosystems and vegetation. The occasional exceedences occurred mainly in northern Bohemia and in the Central Bohemian Region.

Tab. 2.2.26 Stations with the highest values of annual average concentrations at rural stations, NO_x

Fig. 2.2.38 Annual average concentrations of NO_x in 1992–2003 at selected stations

Fig. 2.2.39 Field of annual average concentration of NO_x in 2003

2.2.4.3 Ground-level ozone

For the assessment of vegetation protection against ozone exceedences the national legislation uses, in compliance with the respective EU Directive, the exposure index AOT40 . The survey of stations with the highest values of AOT40 is given in Table 2.2.27. Of the total number of 30 rural and suburban stations for which the AOT40 calculation is relevant according to the legislation, the air pollution target for the protection of vegetation was exceeded at 19 stations in 2003. The target limit value for the protection of vegetation was exceeded at 9 stations operating on the territory defined by the Government Order as the territory on which the limit for the protection of vegetation is not to be exceeded (the stations have the EKO code in the last column of the table).

The spatial distribution of ozone AOT40 in 2003 is shown in the map in Fig. 2.2.41. It is evident that in 58 % of the country�s territory, i.e. in 63.13 % of the territory in which, in compliance with the Government Order the limit value for vegetation protection is not to be exceeded, the AOT40 was exceeded in 2003.

Tab. 2.2.27 Stations with the highest AOT40 values of ozone at rural and suburban stations

Fig. 2.2.40 AOT40 values of ozone in 1995–2003 at selected stations, average of 5 years

Fig. 2.2.41 Field of AOT40 value of ozone, average of 5 years 1999 - 2003

Fig. 2.2.42 Stations with the highest AOT40 values in recent 5 years, 1999–2003

2.2.5 Areas with deteriorated air quality with regard to the protection of ecosystems and vegetation

Based on the mapping of air pollution characteristics distribution for the year 2003 with regard to vegetation protection (Figs. 2.2.37 and 2.2.39) the distribution of air pollution limit values exceedences is shown for annual average concentrations of NO_x and winter average SO₂ concentrations for the protection of ecosystems and vegetation.

The assessment of the respective limit values exceedences is carried out for the territory defined for the protection of ecosystems and vegetation in accordance with the Government Order No. 350/2002 Coll. The final designation of areas with deteriorated air quality with regard to the limit values for SO₂ and NO_x for the protection of ecosystems/vegetation pursuant to the Act No. 86/2002 Coll. for the year 2003 is shown in Fig. 2.2.43.

Table 2.2.28 shows the shares of exceedence of the limit values for the protection of ecosystems and vegetation for individual limit values for NO_x, SO₂ and ozone AOT40 for the territory defined by the new legislation. It is evident that in 63 % of the territory defined as protected areas the target for limit valueozone AOT40 is exceeded, due to exceeding ozone concentrations (Fig. 2.2.44).

Tab. 2.2.28 Shares of the territories for ecosystems and vegetation protection with the LV exceedence, % of the territory of the protected area, 2003

Fig. 2.2.43 Areas with deteriorated air quality with regard to SO₂ and NO_x limit values for the protection of ecosystems/vegetation, 2003

Fig. 2.2.44 Areas with deteriorated air quality for ecosystems/vegetation, exceedence of limit value AOT40, 2003

2.2.6 Conclusions

The adopted environmental legislative documents transposing the new EU directives on ambient air have become an important stimulus for further necessary improvement of ambient air quality in the Czech Republic. The air quality assessment procedures implemented within the transposition of the new EU directives represent undoubtedly the compact and elaborate, though rather complicated system of assessment which should enable to carry out comparable air quality assessment on all-European scale. The limit and threshold values set by the EU directives are deduced thoroughly from the updated recommendations of the World Health Organization, including the limit values for the protection of ecosystems and vegetation. The main consequence of the EU ambient air quality directives transposition is to implement the principle to maintain the state of air quality in those areas where it is good, and to take remedial measures in the form of programs aimed at the improvement of air quality, or the regulation rules for the areas with deteriorated ambient air quality.

The carried out assessment for the year 2003 has taken into account the requirements of the Government Order No. 350/2002. The following problems were indicated with regard to meeting the deadlines set by the national legislation on the protection of ambient air.

The exceedence of limit values for the suspended particles is a major problem in most European cities. The occurrence of suspended particles in ambient air is a rather complicated phenomenon and their actual concentration expressed in mass number is represented only partially by local emission of primary particles, especially by transport emission. Further contribution to the actual concentration is represented by reemission, and the remaining part by secondary inorganic and organic particles created by chemical transformation of gaseous components both of anthropogenic origin (SO₂, NO_x and non-methane volatile organic compounds), and by emission from the natural environment. Thus the problem of exceeded concentrations of suspended particles in European cities will have to be solved both within all-European cooperation, and at local or regional levels, mainly through measures aimed at local heating and by the reduction of traffic emission, including better street cleaning.

Relatively high contribution of secondary particles show that significant decrease of PM₁₀ concentrations will be possible by further decreasing of emission of the components causing the creation of the fraction of secondary particles in atmospheric aerosol. This demands mainly the decreasing of nitrogen oxides and VOC emissions in compliance with the requirement to meet the national emission ceilings, but in such a way that by the deadlines set by the Clean Air Act the air pollution limit values are met for PM₁₀. Further decrease of emissions, mainly nitrogen oxides emissions but also of VOC emissions on a large scale, is the only way of possible decrease of the load caused by exceeding concentrations of ground-level ozone.