AIR POLLUTION IN THE CZECH REPUBLIC IN 2010
Czech Hydrometeorological Institute - Air Quality Protection Division
II.4.2 Czech Republic
II.4.2.1 Air quality with regard to health protection limit values
II.184.108.40.206 Sulphur dioxide
Sulphur dioxide (SO2) emitted from anthropogenic sources is created mainly by burning the fossil fuels (coal and heavy fuel oils) and by smelting ores containing sulphur. In the atmosphere, SO2 is oxidized to sulphates and H2SO4, creating aerosol both in the form of droplets and suspended particles of broad size range. SO2 and the substances originating from it are removed from the atmosphere through wet and dry deposition. SO2 has irritating effects, high concentrations can cause lung function impairment and the change of lung capacity .
The 2010 situation of air pollution caused by SO2 with regard to the limit values set by the legislation is documented by the Tables II.4.2.1 and II.4.2.2 and Figs. II.4.2.1‚ÄďII.4.2.4. The table of annual average SO2 concentrations is also included to illustrate the situation (Table II.4.2.3).
In 2010 neither the limit value for the hourly SO2 concentration nor for the 24-hour SO2 concentration were exceeded in the Czech Republic. In the locality Karvin√° the 24-hour limit value (125 őľg.m-3) was exceeded once in January 2010, nevertheless three cases of such exceedances per one year are necessary to report the exceedance of the limit value. Similarly, in case of hourly concentrations the limit value (350 őľg.m-3) was exceeded in the tolerated number (24), and namely once in the locality Pardubice Dukla and once in Fr√Ĺdek-M√≠stek.
Fig. II.4.2.1 shows the development of the 4th highest 24-hour and 25th highest hourly SO2 concentration in selected localities.
In 2010, in comparison with the year 2009, more than 70 % of localities recorded the increase of the 4th highest 24-hour concentration and the 25th highest hourly concentration. The increase of concentrations was given mainly by the occurrence of unfavourable meteorological and dispersion conditions in the winter period (mainly in January) and due to coldest heating season for the recent 10 years (Fig. I.1.3). It can be expected that certain increase of SO2 concentrations occurred also in the places where there is no measurement, which may be caused by the return to coal combustion in local furnaces in some settlements.
Spatial distribution of the 4th highest 24-hour SO2 concentration is presented in Fig. II.4.2.2. It is apparent that only in approx. 4 % of the territory of the Czech Republic SO2 concentrations exceeded the lower assessment threshold.
Tab. II.4.2.1 Stations with the highest values of the 25th and maximum hourly
concentrations of SO2
Fig. II.4.2.1 4th highest 24-hour concentrations and 25th highest hourly concentrations of SO2 in 2000‚Äď2010 at selected stations
Fig. II.4.2.2 Field of the 4th highest 24-hour concentration of SO2 in 2010
Fig. II.4.2.3 Stations with the highest hourly concentrations of SO2 in 2010
Fig. II.4.2.4 Stations with the highest 24-hour concentrations of SO2 in 2010
II. 220.127.116.11 Suspended particles, PM10 fraction and PM2.5 fraction
The particles contained in the ambient air can be divided into primary and secondary particles. The primary particles are emitted directly into the atmosphere, from the natural sources (e.g. volcanic activity, pollen dust or sea spray aerosols) or anthropogenic sources (e.g. combustion of fossil fuels in stationary and mobile sources, tyre wear particulate matter, brake lining dust, road dust). Secondary particles are mostly of anthropogenic origin and are created in the atmosphere from their gaseous precursors SO2, NOx and NH3 through the process called gas-particles conversion. Their share in total emissions of particles in the Czech Republic is about 90 %. The main sources of total emissions, i.e. primary particles and precursors of secondary particles (SO2, NOx, NH3) in the Czech Republic include power engineering (production of electric and heat energy), transport and manufacturing processes. Due to the diversity of emission sources the suspended particles have various chemical composition and various size. The PM10 suspended particles have serious health impacts appearing already at low concentrations without a clear lower safe concentrations threshold. Health impacts of particles are influenced by their concentration, size, shape and chemical composition. The acute impact of particles may cause the irritation of mucous membranes of the respiratory system, the increased production of mucus etc. These changes may cause hypo-immunity and increase predispositions to respiratory diseases. The recurrent diseases may result in chronic bronchitis and cardiovascular disorders. The acute impact of particles may accentuate the symptoms in asthmatics and increase the total morbidity and mortality of population. The long-term exposure to particles may result in chronic bronchitis or lower life expectancy. Recently it has been proved that the most serious health impacts (incl. increased mortality) are recorded in fine PM2.5 or PM1 fractions which enter the lower parts of the respiratory system when inhaled. The level of health implications is influenced by a number of factors, such as the current health condition of the individual, allergic predisposition or smoking. Children, the elderly and people who have problems with lung or heart disease are the sensitive groups .
Air pollution caused by PM10 remains one of the main problems of air quality assurance. In almost all localities in the Czech Republic there is an apparent increasing trend in air pollution caused by PM10 from 2001 to 2003. In 2004 this trend stopped but in 2005 the PM10 concentrations increased again at almost all localities. In 2006 this trend continued at most localities in annual averages. In 2007, on the contrary, the decrease of PM10 concentrations was recorded. In 2008 the decreasing trend continued at most stations, mainly in daily concentrations. In 2009 there prevailed a slight increase, more marked in the agglomeration Moravian-Silesian Region. In 2010 the PM10 concentrations increased, both in daily and annual characteristics (Figs. II.4.2.5 and II.4.2.6). The greatest increase was recorded again in the zone Moravian-Silesian Region. The growth of concentrations of the suspended particles in 2010 was caused mainly by repeated occurrence of unfavourable meteorological and dispersion conditions in the winter period (January and February) and at the end of the year (October, December). The increase of PM10 concentrations in 2010 was caused probably also by the coldest heating season for the recent 10 years.
It is clear from the data from the localities where the annual limit value was exceeded at least once in the recent 5 years (2006‚Äď2010) that the most loaded areas are: the Ostrava-Karvin√° area, the agglomerations Prague and Brno and larger cities in the Czech Republic. Further, the data show that the highest PM10 loads were recorded in 2006 and 2010, as concerns the assessment of the recent 5 years (Fig. II.4.2.12 and Table II.4.2.6).
In 2010 the most affected area of large coverage was, similarly as in the previous years, the Ostrava-Karvin√° area. The limit value of 24-hour PM10 concentration was exceeded in 2010 in all localities in the agglomeration the Moravian-Silesian Region and in more than half to most of localities in the zones √öst√≠ nad Labem, Central Bohemian, Olomouc and Zl√≠n regions and in the agglomerations Prague and Brno. The limit value exceedance was recorded in 1 to 2 localities also in the zones South Bohemian, South Moravian, Hradec Kr√°lov√©, Liberec, Pardubice and PlzeŇą regions and in the zone Vysońćina Region. The only zone which did not recorded any exceedance in its localities, was the zone Karlovy Vary Region (Table II.4.2.4). Of the total number of 158 localities in which PM10 measurements were carried out in 2010, 83 localities reported exceedances of 24-hour PM10 limit value (in 2009 50 of 148); (Fig. II.4.2.13).
In 2010 there was certain enlargement of the area with above-the-limit 24-hour concentrations of PM10 in the Olomouc Region, Moravian-Silesian Region, Zl√≠n Region, South Moravian Region, √öst√≠ nad Labem Region and the Central Bohemian Region as compared with the year 2009 (Fig. II.4.2.7). Figs. II.4.3.1 shows that PM10 limit value exceedances are still significant for listing the basic administrative units among the areas with deteriorated air quality. Especially in the towns where the PM10 measurements are carried out the 24-hour average concentrations are above the limit value. However, it can be admitted that also in the towns without PM10 measurements the concentrations of this pollutant can be high or exceeding the limit value. The spatial projections of PM10 concentrations show, that in 2010 the limit values for PM10 24-hour average concentration were exceeded in 21.2 % of the territory of the Czech Republic (Fig. II.4.2.7) with approx. 48 % of inhabitants (in 2009 the exceedance was recorded in 4.4 % of the territory with 18 % of inhabitants).
The graphs of courses of 24-hour concentrations of PM10 in 2010 in the localities, where the limit values for annual average and for 24-hour average were exceeded, are shown in Figs. II.4.2.9 and II.4.2.10. The concentrations of PM10 show a clear course with the highest concentrations in the cold months of the year. Higher concentrations of PM10 in the ambient air during the cold part of the year may be influenced both by higher emissions of particles from seasonal sources, and by deteriorated dispersion conditions.
The annual PM10 limit value was exceeded in 25 of 170 localities (in 2009 in 14 of 159 ‚Äď Fig. II.4.2.13), the highest annual averages were recorded in the locality Stehelńćeves (89.8 őľg.m-3), VńõŇôŇąovice (66.1 őľg.m-3) and Bohum√≠n (63.9 őľg.m-3). The limit value was exceeded in 2010 mainly in the localities in the Ostrava-Karvin√° area and in the Kladno area; in Brno, Prague and the Zl√≠n Region there were recorded exceedances in one locality (Table II:4.2.5). The increased concentrations of particles in Stehelńćeves in 2010, in comparison with the previous years, was caused by intensive building activity in the vicinity of the measuring station (new sewerage system). Since 2004 the fine fraction of suspended particles (PM2.5) has been measured in the Czech Republic. In 2010 the measurements were carried out in 38 localities. The measurement results show significant contribution of PM2.5 fraction to air pollution situation, and particularly in the part of the agglomeration Moravian-Silesian Region. When comparing the results with the annual target value (25 őľg.m-3) pursuant to the Government Order No. 597/2006 Coll., on air quality monitoring and assessment, as amended, it is evident that in 12 localities the limit value was exceeded, and namely in the localities in the Ostrava-Karvin√° area (VńõŇôŇąovice, Bohum√≠n, Ostrava-Radvanice Z√ö, Ostrava-PŇô√≠voz, Ostrava-Z√°bŇôeh, TŇôinec-Kosmos and Ostrava-Poruba/ńĆHM√ö), in the agglomeration Brno (Brno-Svatoplukova, Brno-ZvonaŇôka and Brno-L√°ny), in the locality PŇôerov in the zone Olomouc Region and in the locality Zl√≠n in the zone Zl√≠n Region (Table II.4.2.7). In 2010 there was the greatest number of localities with the limit value exceedances since 2007 (Fig. II.4.2.16). The annual average PM2.5 concentrations in the localities which measured this fraction in 2010 are presented in Fig. II.4.2.15 in the form of spot symbols. The annual average PM2.5 concentrations at individual localities in the period 2004‚Äď2010 are presented in Fig. II.4.2.14.
According to the annual course of PM2.5 concentrations with regard to the exceedance of the annual target value (Fig. II.4.2.18) it can be stated that the pollution caused by this pollutant occurs mainly during the cold part of the year (the months of January, February, November, December) Higher concentrations of this pollutant in the cold part of the year are caused by emissions from heating and by deteriorated dispersion conditions.
The measurement results indicate that the ratio between PM2.5 and PM10 is not constant but shows certain seasonal course and, simultaneously, it is dependent on the locality position. In 2010 the ratio, in the average from 18 localities in the Czech Republic simultaneously measuring PM2.5 and PM10 and with sufficient number of values, ranged from 0.66 (August) to 0.85 (December) with lower values in the summer period. In Prague, where the annual course is influenced by a large share of traffic localities, this ratio was from 0.66 (August) to 0.85 (December), in Brno 0.66 (August) to 0.86 (January) and in the Moravian-Silesian Region 0.69 (June‚ÄďAugust) to 0.87 (January). When comparing the ratio with regard to the classification of localities, the ratio in urban localities is 0.68 (June) to 0.88 (December), in suburban localities 0.66 (July) to 0.82 (December), and traffic localities 0.56 (July) to 0.79 (December). It is necessary to take into account that the number of localities with simultaneous measurement of PM2.5 and PM10 is not high.
The seasonal course of PM2.5/PM10 fraction ratio is connected with the seasonal character of several emission sources. Emissions from combustion sources show higher shares of PM2.5 fraction than for instance emissions from agriculture and reemissions during dry and windy weather. Consequently, heating in the winter period can cause the higher share of PM2.5 fraction in comparison with PM10 fraction. The decrease during the spring and early summer is also explained by the increased amount of larger biogenic particles (e.g. pollen) by some authors .
The lowest PM2.5/PM10 ratio is at traffic localities. During fuel combustion the emitted particles occur mainly in PM2.5 fraction and thus the ratio should be high in traffic localities. The fact that this is not the case, accents the significance of emissions of larger particles caused by tire, break lining and road surface abrasion.
Higher PM2.5/PM10 ratio in the localities of the Moravian-Silesian Region is connected with a great share of industrial sources in the Ostrava-Karvin√° area.
Tab. II.4.2.4 Stations with the highest numbers of exceedances of the 24-hour
limit value of PM10
Fig. II.4.2.5 36th highest 24-hour concentrations and annual average concentrations of PM10 in 2000‚Äď2010 at selected stations with UB, SUB, I and T classification
Fig. II.4.2.6 36th highest 24-hour concentrations and annual average concentrations of PM10 in 2000‚Äď2010 at selected rural (R) stations
Fig. II.4.2.7 Field of the 36th highest 24-hour concentration of PM10 in 2010
Fig. II.4.2.8 Field of annual average concentration of PM10 in 2010
Fig. II.4.2.9 Stations with the highest exceedance of LV for 24-hour concentrations of PM10 in 2010
Fig. II.4.2.10 Stations with the highest exceedance of LV for annual concentrations of PM10 in 2010
Fig. II.4.2.11 Numbers of exceedances of the limit value for 24-hour concentration of PM10 in 2010
Fig. II.4.2.12 Annual average PM10 concentrations at the stations with the exceedance of the limit value, 2006‚Äď2010
Fig. II.4.2.13 Share of localities with the exceedance of the limit value for the 24-hour average concentration and annual average concentration of PM10, 2000‚Äď2010
Fig. II.4.2.14 Annual average concentrations of PM2.5 in the ambient air in 2004‚Äď2010 at selected stations
Fig. II.4.2.15 Annual average concentration of PM2.5 at stations in 2010
Fig. II.4.2.16 Share of localities with the exceedance of the target value for the annual average concentration of PM2.5, 2004‚Äď2010
Fig. II.4.2.17 Average monthly PM2.5/PM10 ratio in 2010
Fig. II.4.2.18 Stations with the highest exceedance of LV for annual concentrations of PM2.5 in 2010
II.18.104.22.168 Nitrogen dioxide
In the field of ambient air monitoring and assessment the term nitrogen oxides (NOx) is used for the mixture of (NO) and (NO2) Air pollution limit value for the protection of human health is set for NO2, the limit value for the protection of ecosystems and vegetation is set for NOx.
More than 90 % of the total nitrogen oxides in the ambient air are emitted in the form of NO. NO2 is formed relatively quickly in the reaction of NO with ground-level ozone or with HO2 or RO2 radicals. In a number of chemical reactions part of NOx is transformed to HNO3/NO3-, which are removed from the atmosphere through dry and wet deposition. NO2 is dealt with due to its negative influence on human health. It plays also the key role in the formation of photochemical oxidants.
In Europe, NOx emissions result mainly from anthropogenic combustion processes during which NO is formed in reaction between nitrogen and oxygen in the combusted air, and partly also by oxidation of nitrogen from the fuel. Road transport is the main anthropogenic source (significant shares however, have also air transport and water transport), and also combustion processes in stationary sources. Less than 10 % of total NOx emissions result from combustion directly in the form of NO2. Natural NOx emissions result mainly from soil, volcanic activity and creation of bolts of lightning. Globally, they are important, on the European scale, however, they represent less than 10 % of total emissions . Exposure to the increased NO2 concentrations affects lung function and can cause lower immunity .
The exceedances of annual limit values for NO2 occur only in limited number of stations, and namely in the localities in agglomerations and large cities exposed to traffic. Of the total number of 167 localities in which NO2 was monitored in 2010 the annual limit value was exceeded at 10 stations (Table II.4.2.9). Nine of them are classified as traffic urban, one as background urban. It can be expected that the exceedances of the limit values can occur also at other sites exposed to traffic, where there is no measurement.
The station Prague 2-Legerova (hot spot), aimed at ambient air pollution monitoring caused by traffic, recorded, similarly as in the previous years, the exceedance of the limit value for the hourly concentration. The measurements results at this station confirm the big problem of the Capital city of Prague with the traffic running through the city center. Further five localities recorded the exceedance of the limit value (200 őľg.m-3), nevertheless the number of exceedances remained within the tolerated number (under 18) and thus the limit value was not exceeded.
Fig. II.4.2.19 presents the development of the 19th highest hourly concentration
and the annual average concentration of NO2 in the period 2000‚Äď2010 in selected
localities. In 2002, in comparison with the previous years, this decreasing
trend of NO2 concentrations stopped and in 2003 there was a slight increase of
NO2 pollution at most localities. In 2004 a slight decrease was recorded but in
2005 the increasing trend of NO2 concentrations appeared again, and continued in
2006. In 2007 a marked decrease of NO2 concentrations was recorded due to more
favourable meteorological and dispersion conditions, similarly as in 2008; in
the following year, 2009, on the contrary, most stations recorded a slight
increase of NO2 concentrations. In 2010, in comparison with 2009, there was
recorded a slight increase of annual average concentration in more than 70 % of
localities (113 in total), and 45 localities recorded its decrease.
When constructing the map in Fig. II.4.2.20 also the updated data on emissions from mobile sources in the Czech Republic were regarded. The higher NO2 concentrations can occur also in the vicinity of local communications with intensive traffic and dense local transport network.
Fig. II.4.2.19 19th highest hourly concentrations and annual average concentrations of NO2 in 2000‚Äď2010 at selected stations
Fig. II.4.2.20 Field of annual average concentration of NO2 in 2010
Fig. II.4.2.21 Stations with the highest hourly concentrations of NO2 in 2010
Fig. II.4.2.22 Stations with the highest exceedance of LV for annual concentrations of NO2 in 2010
The insufficient burning of fossil fuels may be an anthropogenic source of air pollution caused by carbon monoxide (CO). These processes occur mainly in transport and in stationary sources, namely household heating.
Increased CO concentrations can cause headache, deteriorated coordination and attention. CO binds to haemoglobin and the increased concentrations of the created carboxyhaemoglobin reduce the capacity of blood for the oxygen transport.
In 2010 carbon monoxide concentrations were measured at 34 localities, classified in most cases as traffic localities in which the highest measured concentrations can be expected. The maximum daily 8-hour running averages did not exceed, similarly as in the previous years, the limit value (10 mg.m-3) at any of the stations (Table II.4.2.10). The highest daily 8-hour average concentration was measured, in the same locality as in the previous two years, and namely in the hot spot locality Ostrava-ńĆeskobratrsk√° (5 544.9 őľg.m-3).
The courses of maximum daily 8-hour running averages for selected localities are presented in Fig. II.4.2.23.
Fig. II.4.2.23 Maximum daily 8-hour running average concentrations of CO in 2000‚Äď2010 at selected stations
Fig. II.4.2.24 Stations with the highest values of maximum daily 8-hour running
average concentrations of CO in 2010
The anthropogenic sources produce more than 90 % of total emissions in the air. The decisive emission sources are combustion processes, mainly mobile sources, representing about 85 % of total anthropogenic emissions of aromatic hydrocarbons. The prevailing share is contributed by exhaust gases 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 the industries that use these compounds to produce other chemicals. Another significant source is represented by loss evaporative emissions produced during petrol handling, storing and distribution.
Exhaust benzene is produced primarily by unburned benzene from fuels. Non-benzene aromatics or non-aromatic hydrocarbons in the fuels can contribute to exhaust benzene emissions. The most significant adverse effects from exposure to benzene are haematotoxicity and carcinogenicity .
In 2010 benzene concentrations were measured in total in 27 localities with valid annual average. The limit value is defined as an annual average concentration 5 őľg.m-3. The value of the limit value was exceeded, similarly as in the previous years, in the locality Ostrava-PŇô√≠voz. Higher concentrations in this area are connected with industrial activities (mainly with coke production). In comparison with the year 2009, approximately two thirds of localities recorded the increase of annual average concentration, one third of localities, on the contrary, recorded its decrease. The courses of annual average concentrations in selected localities are shown in Fig. II.4.2.25. Fig. II.4.2.27 presents the annual course of 24-hour averages in selected localities.
Fig. II.4.2.25 Annual average concentrations of benzene in 2000‚Äď2010 at selected stations
Fig. II.4.2.26 Field of annual average concentration of benzene in the ambient air in 2010
Fig. II.4.2.27 24-hour concentrations at the stations with the highest annual benzene concentrations in 2010
II.22.214.171.124 Ground-level ozone
Ground-level ozone is a secondary pollutant in the ambient air with no significant emission source of its own. It is formed under the influence of solar radiation during complex photochemical reactions mainly between nitrogen oxides (NOx), VOCs and other components of the atmosphere. Ozone is a very powerful oxidizing agent. Ozone impairs mainly the respiratory system and irritates mucous membranes. It causes morphological, biochemical and functional changes and impairs the immune system response. There is evidence for ozone toxicity to vegetation.
The Government Order No. 597/2006 Coll., as amended, requires the assessment of ozone concentrations in relation to human health protection as an average for the latest three years. If the latest three years are not available, the average for the latest two years or one year is taken into account pursuant to the Government Order. In 2010 ozone was measured at 74 localities out of which 12 (16.2 %) exceeded the target value for the three-year period 2008‚Äď2010, or shorter (see Table II.4.2.12). In the locality Zl√≠n the target value was achieved, the number of exceedances of the level 120 μg.m-3 was equal to the maximum admissible cases, i.e. 25.
The comparison of the assessed three-year periods is based mainly on meteorological conditions, i.e. the values of solar radiation, temperature and precipitation in the period from April to September when the highest ozone concentrations are usually measured. In comparison with the previous three-year period 2007‚Äď2009 the number of exceedances of the target value 120 μg.m-3 decreased again, and namely in 52 localities. When comparing the meteorological conditions in the year 2007, which was not included in the 3-year assessment period, and in 2010 to detect the causes of the improvement of ambient air pollution situation, there were measured slightly lower temperatures in 2010 during the period April‚ÄďSeptember (in average by 0.9 įC), and almost all localities monitoring the respective meteorological parameters, recorded the decrease of maximum temperatures and the total values of daily averages of global radiation in the period April‚ÄďSeptember.
According to  the year-to-year differences in ozone concentrations are, at the current level of the concentrations of ground-level ozone precursors, given primarily by the above mentioned meteorological conditions and the influence of precursors concentrations is not much significant. This is confirmed by the fact that, despite the decrease of ground-level ozone concentrations, the annual NO2 concentrations increased, in comparison with the year 2007, in more than 63 % of localities monitoring this pollutant. Similarly the concentrations of most substances included in the VOC group, monitored in detail in KoŇ°etice and LibuŇ°, slightly increased in 2010 in comparison with the year 2007. With regard to rather complicated atmospheric chemical processes during ozone formation and disintegration, its dependence on absolute amount and relative representation of its precursors in atmosphere, connected also with long-range transboundary air pollution and on meteorological conditions, it is very difficult to comment the year-to-year changes in more detail.
Significant improvement of the situation during the two recent 3-year periods is documented by the increase of the share of the area in which the target value was not exceeded, and namely from 6.2 % of the Czech Republicís territory for the period 2006‚Äď2008 to 53 % of the territory for the period 2007‚Äď2009 and up to almost 90 % for the period 2008‚Äď2010.
The localities with the respective numbers of exceedances of the target value (120 őľg.m-3) are presented in Table II.4.2.12). The traffic localities in the cities are the least loaded ones as ozone is degraded there through chemical reaction with NO. It can be expected that the ozone concentrations are below the target value also in other cities with heavier traffic. However, due to the absence of measurements the probable decrease cannot be documented by the use of current methods of map construction.
Fig. II.4.2.28 shows the 26th highest value of maximum 8-hour running average of ozone concentrations (three-year average) in 2000‚Äď2010.
Table II.4.2.12 presents the stations with the highest values of maximum daily 8-hour running average ozone concentrations in three-year average. Fig. II.4.2.30 shows the graph of the number of exceedances of the target value for ground-level ozone and Fig. II.4.2.31 presents the annual courses of maximum daily 8-hour running averages in the localities with the heaviest loads.
Table II.4.2.13 presents the number of hours of the ozone alert threshold exceedance (180 μg.m-3) at selected AIM stations for the period of 1995‚Äď2010.
Tab. II.4.2.12 Stations with the highest values of maximum
daily 8-hour running average concentrations of ozone
Fig. II.4.2.28 26th highest values of maximum daily 8-hour running average of ground-level ozone concentrations (three-year average) in 2000‚Äď2010 at selected stations
Fig. II.4.2.29 Field of the 26th highest maximum daily 8-hour running average of ground-level ozone concentrations in three-year average, 2008‚Äď2010
Fig. II.4.2.30 Numbers of exceedances of the target value for the maximum daily 8-hour running average of ground-level ozone concentrations in three-year average, 2008‚Äď2010
Fig. II.4.2.31 Stations with the highest values of maximum daily 8-hour running
average concentrations of ground-level ozone in 2008‚Äď2010
II.126.96.36.199 Heavy metals
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. In the natural processes
lead is released through the weathering of rocks and volcanic activity .
The long-term exposure to lead results in harmful impacts on biosynthesis of haem (nonproteinic component of haemoglobin), on nervous system and blood pressure in humans. WHO classifies lead as concerns its carcinogenity in 2B group (i.e. possibly carcinogenic to humans) [14, 15].
None of the 65 localities measuring lead concentrations recorded the exceedance of the limit value (500 ng.m-3). The highest annual average was recorded in the locality Ostrava-PŇô√≠voz (34.2 ng.m-3). The second highest annual average was recorded at the station PŇô√≠bram which in the previous years ranked usually behind the most loaded localities from the Ostrava area.
Lead concentrations in all localities remain far below the limit value and do not even reach the lower assessment threshold (see Fig. II.4.2.32). As compared with the year 2009 the concentrations in 42 localities increased and 14 localities, on the contrary, recorded a slight decrease. The courses of short-term (24-hour or14-day concentrations, depending on the measurement schedule of the given station) average concentrations at selected localities are presented in Fig. II.4.2.33.
The stations with the highest values of annual average concentrations are presented in Table II.4.2.14.
Fig. II.4.2.32 Annual average concentrations of lead in the ambient air in 2000‚Äď2010 at selected stations
Fig. II.4.2.33 1/14-day average concentrations of lead in the ambient air in 2010 at selected stations
Globally, the anthropogenic sources of cadmium emission in the ambient air represent about 90 % (mainly iron and steel production, metallurgy of non-ferrous metals, refuse incineration and fossil fuels combustion (brown coal, hard coal and heavy fuel oils) . Emissions from transport are less significant. The remaining 10 % represent natural sources (mainly caused by volcanic activity).
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 in humans .
In 2010 cadmium concentrations were monitored in 65 localities in total. None of them exceeded the target value (5 ng.m-3). Similarly as in 2009 the highest annual average was measured in the locality SouŇ° (2.9 ng.m-3). As compared with the year 2009 there was recorded a slight increase of average annual concentration in approximately two thirds of localities; in one third of localities, on the contrary, it decreased. The target value should be met by 31.12.2012.
The development of annual average concentrations in the period of 2000‚Äď2010 is apparent from Fig. II.4.2.34.
The courses of short-term (24-hour or 14-day concentrations, according to the measurement schedule at the respective station) average cadmium concentrations in selected localities in 2010 are presented in Fig. II.4.2.35.
The stations with the highest values of annual average concentrations are presented in Table II.4.2.15.
Fig. II.4.2.34 Annual average concentrations of cadmium in the ambient air in 2000‚Äď2010 at selected stations
Fig. II.4.2.35 1/14-day average concentrations of cadmium in the ambient air in 2010 at selected stations
Arsenic occurs in many forms of inorganic and organic compounds. Anthropogenic sources produce about three quarters of total emissions in the ambient air. Significant amounts are contributed mainly from combustion processes (brown coal, hard coal and heavy fuel oils), iron and steel industry and production of copper and zinc. Main natural sources of arsenic include mainly volcanic activity, wildfires, weathering of minerals and activity of microorganisms (in wetlands, swamps and circumlittoral areas) .
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 .
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].
In comparison with the previous year 2009 most localities recorded the slight increase of the annual average concentration.
The development of annual average concentrations during the years 2000‚Äď2010 is
apparent from Fig. II.4.2.36.
The stations with the highest annual average concentrations are presented in Table II.4.2.16.
Fig. II.4.2.36 Annual average concentrations of arsenic in the ambient air in 2000‚Äď2010 at selected stations
Fig. II.4.2.37 Field of annual average concentration of arsenic in the ambient air in 2010
Fig. II.4.2.38 1/14-day average concentrations of arsenic in the ambient air in
2010 at selected stations
Nickel is the fifth most abundant element of the earth core, though in the earth crust its percentage share is lower.
The main anthropogenic sources, which globally represent about three quarters of
total emissions, include combustion of heavy fuel oils, mining of nickel-containing
ores and nickel refinement, waste incineration and iron and steel production.
Main natural sources include continental dust and volcanic activity.
About 70 % of particles containing nickel comprise the fraction smaller than 10
őľm. These particles can be transported over long distances. About 30 % of
particles containing nickel have aerodynamic diameter equal or higher than 10 őľm
and quickly settle in the vicinity of the source .
None of the 65 localities measuring nickel concentrations, similarly as in
previous years, exceeded the target value (20 ng.m-3) for nickel annual average
concentrations (Fig. II.4.2.39). The highest annual average concentration was
measured in the locality PŇô√≠bram I.-nemocnice (14.1 ng.m-3) which slightly
exceeded the lower assessment threshold (10 ng.m-3). The slight increase of
concentrations as compared with the year 2009 was recorded in approximately half
of the localities.
Fig. II.4.2.39 Annual average concentrations of nickel in the ambient air in 2000‚Äď2010 at selected stations
Fig. II.4.2.40 1/14-day average concentrations of nickel in the ambient air in
2010 at selected stations
The cause of the presence of benzo(a)pyrene, the main representative of polycyclic aromatic hydrocarbons (PAH) in the ambient air is, similarly as in other PAH, 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 (coal combustion). Mobile sources are represented mainly by diesel motors. The natural background level of benzo(a)pyrene is almost zero with the exception of wildfires .
Approximately 80‚Äď100 % of PAH with five and more aromatic cores (i.e. also benzo(a)pyrene)
are bound mainly to the particles smaller than 2.5 μm, i.e. to the so called
fine fraction of atmospheric aerosol PM2.5 (sorption on the surface of the
particles). These particles remain in the atmosphere for relatively long time (days
to weeks) which enables their transport over long distances (hundreds to
thousands of kilometres).
In 2010 benzo(a)pyrene concentrations were monitored in 33 localities; 23 of them exceeded the target value of 1 ng.m-3 (annual average concentrations). The highest annual average concentration was measured in the locality Ostrava-Radvanice Z√ö (7.2 ng.m-3), where the target value was exceeded more than 7x.
It is necessary to consider that the estimates of the fields of annual average benzo(a)pyrene concentrations (Fig. II.4.2.42), in comparison with other mapped pollutants, are loaded with the greatest uncertainties which result form insufficient density of measurements.
A number of towns and villages were assessed, similarly as in the previous years, as the areas with the exceeded target value. In 2010 the target value was exceeded in 14.47 % of the territory of the Czech Republic (in 2009 it was 2.31 % of the territory of the Czech Republic).
The target value for benzo(a)pyrene should be met by 31.12.2012.
The annual average concentrations calculated from the measured values increased, in comparison with the year 2009, in 18 localities, and, on the contrary, at 13 stations they decreased. The development of annual average concentrations in individual localities during the years 2000‚Äď2010 is apparent from Fig. II.4.2.41.
The increased concentrations during the winter periods (Figs. II.4.2.43 and II.4.2.44) confirm the influence of local furnaces. The annual courses of short-term concentrations (24-hour once in 3 or 6 days) of benzo(a)pyrene in localities with highest annual averages are apparent from Fig. II.4.2.44. The fluctuations of monthly averages of concentrations for different types of stations in 2004‚Äď2010 are shown in Fig. II.4.2.43. Fig. II.4.2.45 depicts benzo(a)pyrene concentrations in individual localities in 2006‚Äď2010 in relation to PM10 concentrations, resp. to its fine fraction PM2.5 to which benzo(a)pyrene is mainly bound.
Fig. II.4.2.41 Annual average concentrations of benzo(a)pyrene in the ambient air in 2000‚Äď2010 at selected stations
Fig. II.4.2.42 Field of annual average concentration of benzo(a)pyrene in the ambient air in 2010
Fig. II.4.2.43 Monthly average concentrations of benzo(a)pyrene in various types of localities, 2004‚Äď2010
Fig. II.4.2.44 24-hour concentrations at the stations with the highest annual concentrations of benzo(a)pyrene in 2010
Fig. II.4.2.45 Concentrations of benzo(a)pyrene and PM10 particles in individual localities, 2006‚Äď2010
II.188.8.131.52 Other substances
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) .
The natural sources (representing about 60 % of total emissions) include mainly mercury evasion from aquatic ecosystems and vegetation, volcanic activity and de-gassing from mercury-rich minerals. As for anthropogenic emissions it is estimated that in Europe approximately 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 (Hg(p)). Most emissions from natural sources are in gaseous form Hg0 .
Studies of occupationally exposed humans have shown adverse effects on the central nervous system and kidneys at high mercury vapour levels . The increased concentrations in the ambient air result 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 spite of the fact that the limit value for mercury has not been set yet, the Czech national legislation recommends, pursuant to the European directives, to carry out its monitoring and assessment according to the annual arithmetic mean.
In 2010 the CHMI ISKO database received data on mercury concentrations in PM10 particles in the ambient air from 2 localities in total (Karvin√°-Z√ö and KoŇ°etice). The highest annual average was measured in the locality Karvin√°-Z√ö (0.29 ng.m-3), in the locality KoŇ°etice it reached the value 0.015 ng.m-3. The concentrations of gaseous mercury were monitored in the localities KoŇ°etice and √öst√≠ nad Labem-mńõsto, however it did not achieve the sufficient data for the calculation of the annual average.
Table II.4.2.19 presents the overview of the stations measuring mercury in the ambient air and the annual average and maximum 24-hour concentrations.
Major part of ammonia emitted in the ambient air is created by disintegration of nitrogenous organic materials from domestic animals breeding. The remaining amount is 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 . Quite significant are ammonia odour annoyance impacts on the population.
Similarly as in the case of mercury, the limit value for ammonia is not defined in the current European and Czech legislation. Ammonia monitoring was carried out, similarly as in the previous years, at 3 localities. The highest annual average concentration was measured at the station Pardubice-Dukla (5 μg.m-3).
Table II.4.2.20 presents the overview of stations measuring ammonia in the ambient air and annual average and maximum 24-hour concentrations.
The trends of SO2, PM10, NO2, NOx and O3 annual air pollution characteristics in the Czech Republic for the period of 1996‚Äď2010 and PM2.5 for the period 2004‚Äď2010 are shown in Fig. II.4.2.46. Result concentrations of pollutants in the Czech Republic and in agglomerations, related to the respective years, represent average values from the stations which measured for the whole monitored period.
In the 90ís air pollution caused by SO2, PM10, NO2 and NOx had a decreasing trend in the whole Czech Republic, and mainly due to a marked decrease of pollutantís emissions. In 1996‚Äď2000 there was apparent a marked decrease of SO2 concentrations (by ca 70‚Äď80 % depending on the respective air pollution characteristic) and PM10 concentrations (by ca 50‚Äď60 %) ‚Äď Fig. II.4.2.471. The development of the trends of concentrations of individual pollutants is influenced by the decrease of emissions, by the change of the composition of industrial production and transport means and the used fuels, On the other hand, there is a great influence of meteorological and dispersion conditions.
Since 2001 the previous decreasing trend stopped and, on the contrary, in comparison with the year 2000, the ambient air pollutantís concentrations stagnated or increased (Fig. II.4.2.48). The decrease of emissions after the year 2000 was not as steep as in the 90ís of the 20th century (Fig. I.1.1) and it can be expected that ambient air quality is presently influenced mainly by meteorological and dispersion conditions in the course of the year.
In 2001‚Äď2003 the concentrations of SO2, PM10, NO2 and NOx increased and in 2003 the reach their maximum levels with regard to the assessment of the development over the recent 10 years. High concentrations of pollutants in the year 2003 were caused both by unfavourable dispersion conditions in February and December, and by subnormal amount of precipitation.
In 2004 this increasing trend of air pollution caused by PM10, NO2 and NOx finished and, on the contrary, certain decrease of these pollutantsí concentrations occurred, reaching almost the levels of the year 2001. In 2005 the PM10 and NO2 concentrations returned back to the increasing trend, in PM10 the increase was steeper, beyond the level of the year 2002, and also PM2.5 concentrations were increased. This increasing trend was confirmed in 2006 in NO2 and in annual PM10 concentrations (at urban stations); more significant increase was recorded in case of one-hour NO2 concentrations ‚Äď it almost reached the level of the year 1997. On the contrary, 24-hour PM10 concentrations recorded a slight decrease. Annual PM2.5 concentrations stagnated. Between 2003 and 2005 a slight decrease of SO2 concentrations was observed. The increase of some air pollution characteristics in 2005 and 2006 was given mainly by deteriorated dispersion conditions.
In 2007 the fluctuating trend of the levels of the above pollutantsí concentrations stopped and there was recorded a marked decrease of air pollution caused by SO2 and PM10 (both in towns and in the country), PM2.5, NO2 and NOx in all monitored air pollution characteristics. The steepest decrease is evident, after the previous increase, in hourly NO2 concentrations. The decrease of pollutantsí concentrations in 2007 was given by more favourable meteorological conditions, especially in January and February. In 2008 the decreasing trend of ambient air pollution caused by SO2 and PM10 continued, the PM2.5 concentrations more or less stagnated. As concerns NO2, there was recorded a slight decrease in daily concentrations, in NOx there was a slight decrease in annual averages at rural stations. The fluctuation of the trends of individual pollutants is caused on the one hand by the decline of emissions, the change of the structure of industrial production and of the used fuels; on the other hand there is a significant influence of meteorological conditions, particularly dispersion conditions.
In 2009, on the contrary, there was a marked increase of air pollution caused by
SO2, PM10, NO2 and NOx roughly to the level of the year 2007 in all these
pollutants (except for PM2.5). The increase of the above pollutantsí
concentrations in the ambient air was given by less favourable meteorological
and dispersion conditions, mainly in January, February and December 2009 as
compared with the year 2008.
The ground-level ozone is the pollutant of a different character than the above assessed pollutants. Ozone is the so called secondary pollutant which reaches its highest concentrations in the warm part of the year. As concerns the period 1996‚Äď2006, it is not possible to clearly conclude the trend of the concentrations, as air pollution characteristics show marked fluctuations. In 2003 there is apparent the increasing trend in concentrations due to long-time very high temperatures and high levels of solar radiation. In 2004 O3 concentrations slightly decreased below the level from the years 1997‚Äď2002, in 2005, on the contrary, they increased slightly above the level from 1997‚Äď2002.
On the contrary, since 2006 the pollutantsí concentrations were decreasing continuously up to 2009. In 2006 the concentrations slightly increased. In 2007 the average from the 26th highest maximum 8-hour running averages slightly decreased. On the contrary, there was a slight increase of the 76th values of maximum 8-hour running averages for the previous 3 years, resulting mainly from the fact that the April‚ÄďSeptember period of the year 2007 was warmer (in the average for the whole Czech Republic by 1.2 įC) than the year 2004 which was included in the previous three-year period but not taken into account for the assessment of the 2005‚Äď2007 period. In the period 2006‚Äď2008 the 76th highest value of maximum 8-hour running averages decreased, probably due to the decrease of the precursorsí concentrations (both NOx and VOC). This decrease is visible in the graph of the trends in all types of localities; also apparent is the decrease of concentrations in the year 2008 alone. The decline of ozone concentrations continued also in the period 2007‚Äď2009, when there was a marked decrease of the number of exceedances of the limit value 120 μg.m-3 in most localities, and, as it is apparent from the graph, the 26th highest value of the maximum 8-hour running average decreased for the year 2009 alone, as well as the average for 3 years. The graphs of trends also show apparently higher concentrations in rural localities as compared with the concentrations from urban and suburban localities, where ozone is removed mainly by emissions from traffic. In 2010 the 26th highest value of maximum 8-hour running average slightly increased, the values of 3-year averages of concentrations decreased again.
Fig. II.4.2.46 Trends of SO2, PM10, PM2.5, NO2, NOx and O3 annual characteristics in the Czech Republic, 1996‚Äď2010
Fig. II.4.2.47 Trends of selected characteristics of SO2, PM10, NO2 and O3 (index, year 1996 = 100) and and PM2.5 (index, year 2004 = 100), 1996‚Äď2010
Fig. II.4.2.48 Trends of selected characteristics of SO2, PM10, NO2 and O3
(index, year 2000 = 100) and PM2.5 (index, year 2004 = 100), 2000‚Äď2010
1The trend of selected air pollution characteristics is expressed in the indexed form, i.e. the level of air pollution caused by the respective pollutant in 1996‚Äď2010 is related to the level (concentration) of the pollutant in 1996 (or in 2000).