AIR POLLUTION IN THE CZECH REPUBLIC IN 2010
Czech Hydrometeorological Institute - Air Quality Protection Division
With regard to the Communication of the Air Quality Protection Division of the Ministry of Environment on delineating zones and agglomerations within the territory of the Czech Republic, air quality assessment in the proposed agglomerations (Prague, Brno and the Moravian-Silesian Region) has been treated with more attention since 2005. In addition to the above agglomerations, special attention is paid in this Yearbook also to the zone ├Üst├ş nad Labem Region due to the concentration of industrial plants, higher population density and also due to the recorded above-the-limit concentrations of some pollutants.
The Capital City of Prague is the area in which a lot of people are exposed to ambient air pollution. Most of the limit values and target values exceedances are connected with significant traffic loads ensuing from the fact that the main routes lead directly through the city centre.
In 2010 the concentrations of suspended particles of PM10 fraction were monitored in Prague in 15 CHMI localities and in 7 Z├Ü localities. The 24-hour PM10 limit value (the value 50 ╬╝g.m-3 must not be exceeded more than 35x in one year) was exceeded in 10 of 17 localities (in the localities with sufficient number of data for the assessment), i.e. in 59 % of localities; in two localities the number of tolerated exceedances was reached, and in the remaining five localities the number of exceedances of the limit value was lower than 35 (Table II.4.2.4). The majority of localities, in which the limit value was exceeded in 2010, are characterized as traffic. In several cases the limit value was exceeded also in the localities defined as background suburban (e.g. Prague 6-Suchdol, Prague 4-Libu┼í). In 2010 there were unfavourable dispersion conditions, similarly as in 2005 and 2006, i.e. in the years when the latest exceedance of the limit value was recorded in these localities (Fig. II.4.1.1). The more frequent exceedances of the 24-hour limit value in 2010 in comparison with the years 2007ÔÇô2009 is documented also by higher share of localities (Fig. II.4.1.2) which exceeded the tolerated number of exceedances1.
The annual PM10 limit value (40 ╬╝g.m-3) was exceeded in one locality of 21, and namely in the locality Prague 5-Svornosti. Within the long-term evaluation since 2000 the annual PM10 concentration has been decreasing, both in traffic localities and background localities. The 2009/2010 year-to-year comparison, however, shows that there was a slight increase of PM10 concentrations in both types of localities (Fig. II.4.1.3).
The concentrations of pollutants show the marked course during the year, and namely due to various meteorological and dispersion conditions and the seasonal character of some emission sources.
In average for all selected localities, the highest PM10 concentration was
reached in February (43 ╬╝g.m-3), the lowest in May (20 ╬╝g.m-3). The highest
average monthly concentration of PM10 (58 ╬╝g.m-3) and the highest number of
exceedances (16x) of the 24-hour limit value (50 ╬╝g.m-3) were reached in
February in the locality Prague 5-Sm├şchov. The highest average monthly
concentration of PM2.5 (36 ╬╝g.m-3) was recorded in the locality Prague
10-┼árob├írova in January. In the average for the selected localities the monthly
PM2.5 concentrations ranged between 30 ╬╝g.m-3 in December and 15 ╬╝g.m-3 in May.
The concentrations of PM2.5 particles were measured in 5 CHMI localities and in 1 Z├Ü locality in 2010. The level of the annual target value for PM2.5 is 25 ╬╝g.m-3 (the Government Order No. 42/2011 Coll. amending the Government Order No. 597/2006 Coll. on air quality monitoring and assessment). Similarly as in the previous years the valid target value was not exceeded in the territory of the Prague agglomeration (Fig. II.4.1.6). There were two exceptions, and namely the year 2005 when the target value way exceeded at one traffic locality, and the year 2006 when the exceedances occurred at two traffic localities. In 2010 the highest annual average concentration (21.1 ╬╝g.m-3) was recorded in the locality Prague 5-Mlyn├í┼Öka.
NO2 concentrations were measured in 20 localities in Prague in 2010. The hourly limit value of NO2 (200 ╬╝g.m-3) was exceeded only in one of 15 localities (the localities with sufficient number of data for the assessment). The value 200 ╬╝g.m-3 was exceeded in the locality Prague 2-Legerova 56x. (Table II.4.2.8).The tolerated number of exceedances is 18. The highest 19th hourly concentration at this locality reached 231 ╬╝g.m-3. As concerns other localities, no exceedances of the hourly NO2 concentration were recorded in 2010.
The annual air pollution limit value for NO2 (40 ╬╝g.m-3) was exceeded in 5 of
20 localities in the Prague agglomeration (Table II.4.2.9), and namely in the
localities Prague 2-Legerova (the annual average concentration reached the value
of 67 ╬╝g.m-3), Prague 5-Svornosti (59 ╬╝g.m-3), Prague 5-Sm├şchov (45 ╬╝g.m-3,
Prague 9-Vyso─Źany (43 ╬╝g.m-3) and Prague 1-n├ím. Republiky (41 ╬╝g.m-3).
The average monthly NO2 concentrations in selected localities in Prague show similar courses as the concentrations of other pollutants. ÔÇô i.e. higher concentrations were recorded during the winter period. Moreover, in NO2 there is an apparent increase of concentrations in February and October. There is a separate locality within the Prague agglomeration, and namely Prague 2-Legerova (hot spot); the NO2 concentrations in this locality are above the limit value in the whole annual course. Then there is the Z├Ü station Prague 5-Sm├şchov which is also situated in the immediate vicinity of the communication and which shows high loads by suspended particles as well. It is followed by the group of localities classified as traffic (with the exception of Prague 1-n├ím. Republiky) with similar courses of the levels ranging around the limit value ((Prague 9-Vyso─Źany, Prague 1-n├ím. Republiky, Prague 8-Karl├şn, Prague 10-Pr┼»myslov├í and Prague 8-Sokolovsk├í).
The remaining two localities (Prague 2-Riegrovy sady and Prague 4-Libu┼í) represent the urban background where the influence of traffic is not as high and the measured concentrations are below the limit value for the most part of the year (Fig. II.4.1.7).
Another problem is caused by benzo(a)pyrene concentrations which in 2010 exceeded the target value in one of two localities in which this pollutant is measured in Prague (Prague 10-┼árob├írova). The year-to-year comparison did not changed markedly ÔÇô the benzo(a)pyrene concentrations decreased in the locality Prague 10-┼árob├írova and they increased in the locality Prague 4-Libu┼í. The long term course of benzo(a)pyrene concentrations in the localities in the Prague agglomeration is depicted in Fig. II.4.1.8. The concentrations of benzo(a)pyrene show, similarly as the above mentioned pollutants, the marked annual courses with the maxima in the winter period (due to the seasonal sources, worse dispersion conditions and easier gas-particles conversion) and with the minima in the summer period (due to the end of heating season and chemical and photochemical disintegration of benzo(a)pyrene. Benzo(a)pyrene concentrations showed also the increased values in October 2010 when in Prague (and other areas of the Czech Republic) there occurred unfavourable dispersion conditions (Fig. II.4.1.9).
The results of the measured concentrations of PM10, NO2 and benzo(a)pyrene suggest the serious need to find the solution for the traffic situation within the agglomeration.
At the locality Prague 5-┼śeporyje, where the target value for arsenic was exceeded in 2007 and 2008, the annual average concentration of arsenic decreased below the target value both in 2009 and 2010.
In 2010 (in the average for 3 years 2008ÔÇô2010) the target value for the ground-level ozone was exceeded relatively closely in the locality Prague 6-Suchdol where the 26th highest maximum daily 8-hour running average reached 121 ╬╝g.m-3. Further high values, however closely below the limit value, were recorded in the localities Prague 4-Libu┼í (117 ╬╝g.m-3) and Prague 5-Stod┼»lky (119 ╬╝g.m-3). In comparison with other pollutants the ground-level ozone shows the inverse course (Fig. II.4.1.10), i.e. ozone concentrations reach the maximum values in the spring (due to the cumulation of precursors in the ambient air) and in summer (due to favourable conditions for the creations of ozone ÔÇô high intensity of solar radiation and high temperatures, low air humidity or windless conditions).
Fig. II.4.1.1 The number of exceedances of the 24-hour limit value of PM10 in selected localities (the localities with complete data series for the respective years), Prague agglomeration, 2000ÔÇô2010
Fig. II.4.1.2 The share of localities (with complete data series for the respective years) in the territory of Prague agglomeration with exceedances of the 24-hour limit value of PM10, 2000ÔÇô2010
Fig. II.4.1.3 The annual average concentrations of PM10 in selected traffic and background localities (the localities with complete data series for the respective years), Prague agglomeration, 2000ÔÇô2010
Fig. II.4.1.4 The annual course of monthly concentrations of PM10 and the number of exceedances of the 24-hour limit value of PM10, Prague agglomeration, 2010
Fig. II.4.1.5 The annual course of monthly concentrations of PM2.5, Prague agglomeration, 2010
Fig. II.4.1.6 The annual average concentrations of PM2.5 in selected localities, Prague agglomeration, 2004ÔÇô2010
Fig. II.4.1.7 The annual course of monthly concentrations of NO2, Prague agglomeration, 2010
Fig. II.4.1.8 The annual average concentrations of benzo(a)pyrene, Prague agglomeration, 2000ÔÇô2010
Fig. II.4.1.9 The annual course of monthly concentrations of benzo(a)pyrene, Prague agglomeration, 2010
Fig. II.4.1.10 The annual course of monthly concentrations of ozone, Prague agglomeration, 2010
Fig. II.4.1.11 Field of the annual concentration of NO2, Prague agglomeration, 2010
Fig. II.4.1.12 Field of the 36th highest 24-hour concentration of PM10, Prague agglomeration, 2010
Air pollution monitoring network
In 2010 the Brno agglomeration carried out air quality measurements at 13 stations of air pollution monitoring operated by 3 institutions: Czech Hydrometeorological Institute (air pollution monitoring incl. sampling accredited according to ─îSN EN ISO/IEC 17025:2005), the Municipal Council of the city of Brno and the Health Institute in Brno.
The estimate of the size of polluted areas
The 24-hour limit value for PM10 is constantly exceeded in the territory of the Brno agglomeration. The largest area of the agglomeration affected by the increased concentrations was recorded in 2005, the lowest coverage was measured in 2004. The marked increase of the share of the territory with the exceeded 24-hour limit value for PM10 in 2005 and 2006 was caused mainly by meteorological conditions (long cold winter 2005/2006, frequent occurrence of temperature inversions etc.) and the related anthropogenic activities (longer heating season, the necessity of road spreading, cold starting of the cars etc.). Similar situation occurred also in the year 2002. In addition to the 24-hour limit value also the limit value for the average annual PM10 concentration was exceeded in the above mentioned years. In 2010 the limit value for the average annual concentration was exceeded, similarly as in the previous year, only at the traffic station Brno-Svatoplukova. The limit value for 24-hour concentration was exceeded again in all traffic localities, in 2010, however, the limit value was exceeded also at background stations Brno-Tu┼Öany and Brno-L├íny. The background locality Brno-Sob─Ť┼íice has not recorded any exceedances.
After two years of under-the-limit concentrations there was exceeded the 24-hour limit value at the background station Brno-Tu┼Öany. This was caused mainly by meteorological conditions right at the beginning of the year resulting in high PM10 concentrations in the cold part of the year and in high number of exceedances (January ÔÇô 17, February ÔÇô 11 and December ÔÇô 14 of the total number of 50). The highest concentrations of PM2.5 particles, for which the limit value 25 ╬╝g.m-3 is valid in the European legislation, are also measured mainly in traffic localities. If the limit value was valid already in 2010, the exceedance would occur in the traffic localities Brno-Svatoplukova, Brno-Zvona┼Öka and also in the locality Brno-L├íny classified as a background locality. The locality Brno-L├íny however, is highly influenced by traffic in highway D1 (at 400 m distance), especially as concerns fine particles and nitrogen oxides. Brno-Tu┼Öany with the average annual PM2.5 concentrations 23.8 ╬╝g.m-3 is the only locality which does not exceed the limit value 25 ╬╝g.m-3. The above facts suggest that the exceedance of the limit values for PM10 in the Brno agglomeration has its most significant contribution in traffic.
In the recent years the limit value for the annual average concentration of NO2 has also been exceeded in the Brno agglomeration. The limit value exceedances occur regularly at traffic stations. The increased concentrations are contributed by higher intensity of traffic and also by meteorological conditions. In 2010 the localities Brno-st┼Öed, Brno-Svatoplukova and Brno-├Üvoz (hot spot) exceeded the LV+MT. As for the hourly limit value, most localities in the Brno agglomeration ranged between the lower and upper assessment thresholds in 2010.
Other limit values for SO2, CO, Pb and benzene are not exceeded in the Brno agglomeration. On the contrary, the concentrations of individual pollutants, except for benzene, do not reach the lower assessment threshold. Therefore the number of selected measurements was limited in the Brno agglomeration, particularly in case of SO2.
In the territory of the Brno agglomeration the target values for tropospheric ozone and benzo(a)pyrene are also exceeded. The tropospheric ozone concentrations are recorded at the levels close to the target value in the long term in the whole territory of the agglomeration, but the results are not practically different from those in the remaining part of the Czech Republic.
Benzo(a)pyrene is one of the polycyclic aromatic hydrocarbons (PAH), originating mainly by the combustion of solid and liquid fuels. The increased concentrations of benzo(a)pyrene in the Brno agglomeration can thus be expected mainly in the vicinity of the major line sources. At present benzo(a)pyrene is measured in 2 localities in the Brno agglomeration. The station Brno-Masn├í (background type), situated, however, in the locality strongly influenced by traffic, reached the same value of concentration as in 2009, i.e. 1.2 ╬╝g.m-3, and thus the target value was exceeded. The average annual B(a)P concentration in the locality Brno-L├ş┼íe┼ł reached only 0.8 ╬╝g.m-3 in 2010, which is the worse result than in 2009, nevertheless the target value was not exceeded. The dispersion study elaborated for the Municipal Council shows that the most loaded area as concerns benzo(a)pyrene concentrations is situated in the vicinity of the big city circuit in the locality Zvona┼Öka and near the Brno main railway station.
The remaining pollutants with the set target values (heavy metals arsenic,
cadmium and nickel) have been reaching the concentrations only below the lower
assessment threshold during several latest years.
The trend of concentrations of major pollutants in 2010
The pollutants exceeding the limit value or the target value were selected to show more detailed development of the concentrations, and namely PM10 (and PM2.5) particles, NO2, benzo(a)pyrene and tropospheric ozone.
In case of the average annual PM10 concentrations individual types of stations in the Brno agglomeration were averaged and compared with the regional background station Mikulov-Sedlec. Fig. II.4.1.13 shows clearly that there is relatively good correlation between the trends of concentrations from background stations and the regional background station, especially in several recent years the measured concentrations have had similar values. The trend of traffic stations differs in some years from the background stations; in the recent years the averaged concentrations at traffic stations are by about 10 ╬╝g.m-3 higher than the concentrations in background localities.
The average monthly PM10 concentrations at individual stations in the Brno agglomeration in 2010 are depicted in Fig. II.4.1.14. In addition to the measured concentrations the figure shows also the sums of monthly precipitation documenting the high concentrations of particles in October 2010. The precipitation at the professional station Brno-Tu┼Öany amounted only to 8.6 mm for the whole October. The combination of these factors influenced the situation in the territory of the Brno agglomeration (but also at the regional background station Mikulov-Sedlec), and namely by increasing the average monthly PM10 concentrations to the level of February or December values (Fig. II.4.1.14). The lack of precipitation prevented the wash out of the dust from ambient air and simultaneously supported the re-suspension of particles. The dispersion study based on the results of the 15-year measuring of dust and meteorological parameters at the station Brno-Tu┼Öany shows that in the period without precipitation (at least 5 days without precipitation) the PM10 concentrations are in average by 6.1 ╬╝g.m-3 higher than the average PM10 concentrations for the whole period.
The highest number of exceedances of the concentration 50 ╬╝g.m-3, occurred in the cold part of the year, and namely in January, February and December. The graph in Fig. II.4.1.15 shows the numbers of exceedances in individual months of the year 2010 at selected stations carrying out air pollution monitoring.
The fine fraction PM2.5 was measured at 4 stations in the Brno agglomeration in 2010 ÔÇô 2 traffic and 2 background stations. Both traffic stations would exceed the limit value for the average annual PM2.5 concentration 25 ╬╝g.m-3. As concerns background localities, the upcoming limit value was exceeded only in the locality Brno-L├íny which is influenced by traffic in highway D1 (at 400 m distance) and thus polluted by fine fraction particles and gases. The only locality, and namely Brno-Tu┼Öany, would not exceed the future limit value. The average monthly shares of PM2.5 in PM10 in the locality Brno-Tu┼Öany in 2010 are depicted in Fig. II.4.1.16. It is apparent that the share of PM2.5 in PM10 has a slightly convex character. In the locality Brno-Tu┼Öany the share of PM2.5 in PM10 ranges from 65 % (August) to 90 % (February); the 2010 average of PM2.5 in PM10 was 78 % which is by about 5 % more than in 2009. This locality, as the only one, uses radiometry (accredited according to ─îSN EN ISO/IEC 17025:2005), and moreover, the measurements are carried out by two separate instruments.
The average annual concentrations of NO2 (Fig. II.4.1.17) are to a certain extent dependent on the locality disposition ÔÇô traffic localities are exposed to the highest air pollution loads of NO2 due to emissions from traffic, which in case of NOx represent about 80 % in the Brno agglomeration. After the averaging of traffic and background localities, incl. the comparison with the regional background locality in Mikulov-Sedlec, the highest loads were confirmed in traffic localities (Fig. II.4.1.17). The graph shows clearly that the background concentrations in Brno are approx. by 10 ╬╝g.m-3 higher than the regional background, air pollution load in the localities exposed to traffic is by another 15ÔÇô20 ╬╝g.m-3 higher than the background of the Brno agglomeration.
The influence of traffic on NOx concentrations is clear from the proportion of NO and NO2 concentrations. The higher the proportion, the higher the traffic load of the locality. As apparent from Fig. II.4.1.18, the locality with the lowest load is the background station Mikulov-Sedlec, followed by the background locality Brno-Tu┼Öany. The low proportion is reached also in the traffic locality Brno-Arboretum which, however is strongly influenced by the local flora. On the contrary, the proportion in further background locality, Brno-L├íny, is close to and occasionally higher than the proportion of the traffic locality Brno-st┼Öed. In case of the locality Brno-L├íny there is probably the influence of the highway D1 (at 400 m distance). The locality with the highest traffic loads is Brno-Svatoplukova situated in the city quarter ┼Żidenice, in the immediate vicinity of the big city circuit, partly enclosed in the corridor of buildings of the Vinohrady quarter. This part of the big city circuit often suffers from tailbacks and poor airing. Therefore this is the most polluted locality within the whole Brno agglomeration as concerns the highest NOx concentrations as well as the highest levels of dust.
Benzo(a)pyrene is measured only in two localities in the Brno agglomeration. The locality Brno-Masn├í is exposed mainly to traffic loads, the locality Brno-L├ş┼íe┼ł represents the background of the city of Brno with low impact of traffic and is partly influenced by small sources. This results in the increase of concentrations of all PAH during the heating season. The average monthly concentrations in the locality Brno-L├ş┼íe┼ł are depicted in Fig. II.4.1.19. The figure shows that during the summer season (MayÔÇôSeptember, without heating) the concentrations of almost all PAH are zero or very low, in spite of the fact that this locality reaches, according to the dispersion study, the local maxima for these substances produced by the incinerator of the SAKO Brno, a.s. company. On the contrary, during the heating season the concentrations are increasing, the highest values are recorded in January and December, i.e. in the months with the lowest temperatures demanding intensive heating; moreover the dispersion conditions are usually most unfavourable in these months.
Tropospheric ozone exceeds the limit value set by the Government Order No. 597/2006 Coll. in the major part of the territory of the Czech Republic. In the Brno agglomeration the coverage is in fact in background localities where the measured concentrations are close to the target value and in most cases this target value is exceeded. On the contrary, the concentrations in traffic localities do not reach the target value. The exceedances occur mainly in summer as there are most suitable conditions for photochemical creation of tropospheric ozone from NO2 and VOC. These photochemical reactions are influenced by solar radiation (necessary for the reactions). The graph in Fig. II.4.1.20 presents the 26th highest 8-hour running average concentrations of tropospheric ozone in individual localities of the Brno agglomeration, the comparison with the regional background station in Mikulov-Sedlec. The concentrations of tropospheric ozone are influenced both by meteorological conditions (solar radiation, temperature) and the characteristics of the locality (traffic, background). In 2010 any of the localities, including the regional background locality Mikulov-Sedlec, did not exceed the target value.
Unlike the previous pollutants the highest ozone concentrations are measured in the locality Mikulov-Sedlec; very similar concentrations are measured also in the background locality of the Brno agglomeration (Brno-Tu┼Öany), and the lowest concentrations are measured in traffic localities (Brno-st┼Öed and Brno-Zvona┼Öka). These differences are connected with ozone reactivity, i.e. with the amount of possible reactants in the ambient air. Ozone is a very strong oxidation agent which easily reacts with a lot of compounds in the ambient air, incl. the pollutants (as for instance NO emitted by the traffic), and therefore in the localities with the highest pollutantsĺ concentrations ozone is able to react much more intensively (and thus reduce its concentration in the ambient air). This is the reason why the lowest concentrations of tropospheric ozone are measured in traffic localities, and the highest ones, on the contrary, in the localities not much influenced by the pollutants. The locality Brno-Arboretum is classified as the traffic locality, however, it is located in the Botanical garden, enclosed in the greenery, and thus the recorded O3 concentrations correspond to those at the background localities.
The above facts show that the Brno agglomeration has its delineated areas with deteriorated air quality, mainly due to high traffic intensity. The traffic localities record the exceedances of the limit values for PM10, NO2 and the target value for benzo(a)pyrene. The draft and the implementation of the measures aimed at the transport system and the line sources should be the priorities for the solution of the problem of ambient air quality in the Brno agglomeration. The background localities situated outside the city centre with traffic loads (Brno-Tu┼Öany, Brno-Sob─Ť┼íice) are influenced to a significant extent also by small sources (household heating) from neighbouring municipalities. Therefore, during longer winters with low temperatures and unfavourable dispersion conditions (inversion) there may occur exceedances of the 24-hour PM10 limit value also in the localities not influenced by traffic (e.g. Brno-Tu┼Öany).
Fig. II.4.1.13 The average annual PM10 concentrations at background and traffic stations, Brno agglomeration, 2002ÔÇô2010
Fig. II.4.1.14 The relation between average monthly PM10 concentration and the total precipitation in 2010
Fig. II.4.1.15 The numbers of exceedances of 24-hour limit value of PM10 concentration 50 ╬╝g.m-3 in individual months of the year 2010
Fig. II.4.1.16 The average monthly concentrations of PM2.5 and PM10, PM2.5/PM10 proportions, Brno-Tu┼Öany, 2010
Fig. II.4.1.17 The average annual NO2 concentrations at background and traffic stations, Brno agglomeration, 2002ÔÇô2010
Fig. II.4.1.18 The influence of traffic on NOx concentrations ÔÇô NO/NO2 proportions, Brno agglomeration, 2002ÔÇô2010
Fig. II.4.1.19 The average monthly PAH concentrations, Brno-L├ş┼íe┼ł, 2010
Fig. II.4.1.20 26th highest of maximum daily 8-hour running average of O3, Brno agglomeration, 2002ÔÇô2010
Fig. II.4.1.21 Field of the annual concentration of NO2, Brno agglomeration, 2010
Fig. II.4.1.22 Field of the 36th highest 24-hour concentration of PM10, Brno agglomeration, 2010
Air pollution in 2010 ÔÇô northern Moravia and Silesia
In January 2010 continued the unfavourable air pollution situation from December 2009 and culminated in episodes of smog situations with significantly above-the-limit concentrations of suspended particles of PM10 fraction and the announcement of the regulatory signal for the large sources  in the Ostrava-Karvin├í area on 23ÔÇô27 January and on 9ÔÇô12 and 17ÔÇô20 February. The above-the-limit daily values occurred repeatedly also in March 2010. The worst situation was in the Ostrava-Karvin├í area, but the January episode affected the entire area of northern and central Moravia and Silesia. On 25 January most stations measured the highest maximum daily concentrations of pollutants over several recent years. The air pollution situation deteriorated again at the end of the year 2010. The first episode of above-the-limit PM10 concentrations in the winter season, along with the announcement of the regulatory signal for the sources in the Ostrava-Karvin├í area, occurred already on 12ÔÇô14 October, followed by further episodes on 3ÔÇô6 and 22ÔÇô26 December.
Concentrations of PM10 with multiple exceedances of the daily limit value 50 ╬╝g.m-3 influenced also the average annual values. After several years with favourable air pollution situation the average annual concentrations increased (Fig. II.4.1.23). The situation was comparable with the years 2005 and 2006. The number of days with above-the-limit daily concentrations of PM10 particles also increased.
In 2010 increased also the annual average concentrations of other pollutants, e.g.
SO2, NO2, benzene. Most localities of the Ostrava-Karvin├í area exceeded the
annual limit value for PM2.5 fraction of suspended particles. The above-the-limit
benzene concentrations were measured again in the locality Ostrava-P┼Ö├şvoz.
Smog situation in the Ostrava-Karvin├í area from 23 to 27 January 20102
During the last decade of January 2010 there occurred unfavourable dispersion conditions in the whole area of the Moravian-Silesian and Olomouc regions and in the Silesian Voivodeship, connected with the extensive anticyclone with the centre above northern Russia and with low air temperatures. As a result, there created a markedly unfavourable air pollution situation in the Ostrava-Karvin├í area and in the adjacent part of Poland, during which the 24-hour average concentrations of PM10 exceeded, for several successive days in multiple levels, not only the daily limit value set by , but also the alert threshold set by . Consequently, smog situation formed in the whole area on 23ÔÇô27 January 2010. During the same period the increased concentrations of PM10 suspended particles were recorded also in other areas of the Czech Republic.
At the beginning of the third decade of January the massive anticyclone with the centre above northern Russia stretched from the northeast to central Europe (Fig. II.4.1.24). Along its southwestern edge cold continental air flowed to the territory of the Czech Republic, mainly at lower levels. The whole central Europe had continuous snow cover and the low clouds gradually dissolved and the wind became weaker. Under these conditions there occurred, mainly at lower altitudes further cooling of the air mass, which resulted in a gradual strengthening of temperature inversion.
During the following days the anticyclone above northeastern Europe slightly weakened and its centre moved slowly towards southwest above the Baltic States. Due to the cloudless character of the weather with only weak ground-level air circulation the air temperature at lower altitudes of the Moravian-Silesian Region was decreasing day by day. On 24 and 25 January it ranged mostly between -17 ░C and -23 ░C, with no significant change in the mountains with most frequent values around -10 ░C.
Only during 27 January 2010 the centre of the anticyclone rapidly moved from the central Europe above the British Islands, and later above the eastern part of the Atlantic Ocean. A significant trough of low pressure moved from northwest to central Europe; it was associated with a frontal system which resulted in significant changes in meteorological conditions for dispersion of pollutants in the atmosphere, mainly the strengthening of ground-level atmospheric circulation, and the exchange of air masses (Fig. II.4.1.25). The warm air broke rapidly into the Czech Republic, which was cleaner as regards the content of pollutants, i.e. oceanic air form northeastern parts of the Atlantic.
Fig. II. 4.1.28 shows the wind roses calculated from hourly measurements of wind direction at the stations Lys├í hora, Mo┼ínov, Raciborz and Katowice from 01:00 CET on 23. 1. to 12:00 CET on 27. 1. with low wind velocities at lowland stations. While in this period the total frequency of wind directions at Lys├í hora was NE+E+SE 78 %, Katowice recorded the most frequent directions NE+E (68 %), in Mo┼ínov N+NE (45 %) and calm 34 % , and at the station Raciborz SE+S (39 %), but also W+NW (35 %). It seems that the station Raciborz, unlike Mo┼ínov, is no longer influenced by windward or leeward effect of the Moravian Gate.
The basic picture of the level of air pollution caused by PM10 on the days with smog situation in the Ostrava-Karvin├í area is given by the available 24-hour concentrations measured at the assessed stations (Table II.4.1.1). By way of illustration, the table shows also the concentrations measured on 22 and 28 January, i.e. on the days before and after the smog situation. The average value of all concentrations presented in the table for the period from 23 to 27 January is more than 5x higher than the similar values for 22 and 28 January. The minimum concentrations measured from 23 to 27 January at individual stations were 1.6ÔÇô5.8x higher than the daily limit value 50 ╬╝g.m-3 and the maximum measured concentrations exceeded this value 3.9ÔÇô11.4x. To illustrate the situation, bold highlighted concentrations in the table exceeded the daily limit value more than 8x. The minimum 24-hour concentrations occurred at all stations in the Ostrava-Karvin├í area on the last day of the smog situation, i.e. on 27 January, when the short-time (1-hour) concentrations began to decrease in the afternoon hours. The maximum concentration 890 ╬╝g.m-3 was measured at AMS Ostrava-Z├íb┼Öeh on 25January in the hour 15:00ÔÇô16:00 CET and the second highest concentration 811 ╬╝g.m-3 was measured at AMS V─Ť┼Ö┼łovice on 27 January in the hour 9:00ÔÇô10:00 CET. The Polish stations did not recorded such a quick emergence of the smog situation and at the stations Wodzis│aw, Gliwice and Zabrze the maximum daily concentrations fall on the last day of the episode. The area with high PM10 concentrations gradually expanded during the assessed period and apart from the Moravian-Silesian Region also further areas of the Czech Republic were affected. The concentrations higher than the alert threshold 150 ╬╝g.m-3 were recorded on 24ÔÇô26 January also in other Moravian regions and on 26 January also in the Hradec Kr├ílov├ę Region.
Fig. II:4.1.29 presents the maps of air pollution published on CHMI web site (portal.chmi.cz). The maps have only informative character; they are created on the basis of modelling with the use of the measured and non-verified data from automated monitoring stations (AMS). They may contain erroneous data and may be incomplete. The last figure shows also the air pollution map of 28 January 2010 to illustrate the significant impact of the change of meteorological conditions on air pollution situation.
During the smog situation, from 23 to 27 January 2010, the air pollution situation worsened as concerns also SO2 and NO2, nevertheless the situation was not as marked as in suspended particles and, in fact, the valid limit values were not exceeded. On one day only the daily limit value 125 ╬╝g.m-3 for SO2 was exceeded (134 ╬╝g.m-3 at AMS Karvin├í on 25. 1.).The measured 1-hour concentrations of SO2 remained far below the short-time limit value 350 ╬╝g.m-3 and the alert threshold; the maximum measured 1-hour concentration of NO2 193 ╬╝g.m-3 measured in the hour 15:00ÔÇô16:00 CET at AMS Ostrava-Z├íb┼Öeh (i.e. at the same station and on the same day as the maximum short-time concentrations of PM10 and PM2.5) reached 97 % of the value of the alert threshold for the warning signal. The average of all short-time concentrations in the period 23ÔÇô27 January is 2.9x higher (for SO2) and 2.3x higher (for NO2) than the average for the days 22 and 28 January.
The 8-hour limit value 10,000 ╬╝g.m-3 for CO was not exceeded at any station, even at the traffic station Ostrava-─îeskobratrsk├í, at which the highest values are usually measured; the highest measured 1-hour value reached 5,837 ╬╝g.m-3 at the station Ostrava-─îeskobratrsk├í.
All the above information positively confirm the decisive influence of meteorological conditions on the formation, course and termination of the described smog situation. The decisive influence of meteorological conditions for the dispersion of pollutants on current ambient air quality is shown clearly in the already commented figures. In addition, Fig. II.4.1.32 is presented to show for each hour of the assessed period 22ÔÇô28 January the following:
It is apparent from the figure how the level of air pollution increased with the decrease of wind velocity and temperature gradient, and vice versa, the significant decrease of concentrations occurred after the parallel strengthening of air circulation and the receding of temperature inversion. In the period with the least favourable conditions also the lowest air temperatures were measured. This factor could also have negative impact on air pollution situation because during the heating season, with the decrease of temperatures, the emissions from local sources increase.
Air pollution situation from January 2010 showed again that the long-lasting unfavourable dispersion conditions result in the increase of PM10 suspended particles up to multiple levels of limit values not only in the industrial area Ostrava-Karvin├í and the adjoining Silesian Voivodeship in Poland. It is also apparent that the situations with multiple exceedances of PM10 limit values will repeat in the future.
The latest similar unfavourable situations with high PM10 concentrations occurred in Ostrava-Karvin├í area in January 2006 and in February 2005. During those episodes the conditions neither for the announcement of the warning signal nor for the regulatory signal, pursuant to the then valid Decree No. 553/2002 Coll. were fulfilled, i.e. with regard to 1-hour SO2 and NO2 concentrations. However, pursuant to the current legislation , taking into account the 24-hour PM10 concentrations, the conditions for announcing the warning and regulatory signals would be fulfilled in the Moravian-Silesian Region in both above episodes.
The overall level of air pollution caused by PM10 suspended particles in January 2010 was higher than during the similar situations in February 2005 and January 2006, even though the maximum 24-hour concentration measured in January 2006 exceeded 600 ╬╝g.m-3, and were thus higher than in January 2010. The smog situation of January 2010 also had the longest duration.
Fig. II.4.1.23 Annual average concentrations of suspended particles of PM10 fraction at the stations in northern Moravia 1996ÔÇô2010
Fig. II.4.1.24 Synoptic situation on 22.1.2010
Fig. II.4.1.25 Synoptic situation on 28.1.2010
Fig. II.4.1.26 Air temperature in the period 22.1.ÔÇô29.1.2010
Fig. II.4.1.27 Wind velocity in the period 22.1.ÔÇô29.1.2010
Fig. II.4.1.28 Wind roses
Fig. II.4.1.29 Maps of 24-hour concentrations of PM10 based on real-time non-verified data, 19.1.ÔÇô28.1.2010 (source: portal.chmi.cz)
Fig. II.4.1.30 Hourly concentrations of PM10 in the Ostrava-Karvin├í area, 22.1.ÔÇô29.1.2010
Fig. II.4.1.31 Hourly concentrations of PM10 in the Silesian Voivodeship, 22.1.ÔÇô29.1.2010
Fig. II.4.1.32 Hourly concentrations of PM2.5 in the Ostrava-Karvin├í area, 22.1.ÔÇô29.1.2010
Fig. II.4.1.33 Meteorological conditions for dispersion, 22.1.ÔÇô29.1.2010
Fig. II.4.1.34 Field of the annual concentration of NO2, Moravian-Silesian agglomeration, 2010
Fig. II.4.1.35 Field of the 36th highest 24-hour concentration of PM10, Moravian-Silesian agglomeration, 2010
The ├Üst├ş nad Labem Zone
The ├Üst├ş nad Labem Region is defined as a zone. This area has high population density and is highly industrialized, and thus a number of pollutants have above-the-limit concentrations.
In 2010, data on pollutantsĺ concentrations were submitted to the ISKO database from the measurements in 36 localities in the ├Üst├ş nad Labem Region (19 CHMI, 10 ─îEZ, 5 Z├Ü, 1 S┼áZE ┼Żatec). Only several localities measured all pollutants.
PM10 concentrations were measured in 28 localities. The exceedances of the 24-hour limit value for PM10 were measured in 16 localities: D─Ť─Ź├şn (the limit value 50 ╬╝g.m-3 exceeded 73x), ├Üst├ş n.L.-V┼íebo┼Öick├í hot spot (69x), ├Üst├ş n.L.-m─Ťsto (63x), Most (60x), Lom (58x), Krupka (49x), Litom─Ť┼Öice (49x), Chomutov (48x), Tu┼íimice (48x), Mil├í (42x), Doksany (41x), Kostomlaty pod Mile┼íovkou (40x), Teplice (40x), Drou┼żkovice (37x) and Strojetice (37x). As compared with the year 2009, when the limit value exceedances occurred in 7 localities, the situation deteriorated. In 2010 the exceedance of the PM10 annual limit value was not recorded at any station in the ├Üst├ş nad Labem Region, the highest annual average concentration of PM10 was measured at the stations Lom (35.7 ╬╝g.m-3), Most (35.5 ╬╝g.m-3), ├Üst├ş n.L.-V┼íebo┼Öick├í (35.4 ╬╝g.m-3), D─Ť─Ź├şn (34.5 ╬╝g.m-3) and ├Üst├ş n. L.-m─Ťsto (33.0 ╬╝g.m-3).
PM2.5 particles were measured in 7 localities in the ├Üst├ş nad Labem Region. The highest annual average PM2.5 concentration was recorded in the locality Teplice; it reached the value 22.7 ╬╝g.m-3. This value is below the limit value for the annual average concentration pursuant to the Directive 2008/50/EC.
In 2010 NO2 concentrations were measured in 32 localities in total in the ├Üst├ş nad Labem Region (out of which 19 CHMI). The station ├Üst├ş n.L.-V┼íebo┼Öick├í, which is significantly influenced by traffic, exceeded the annual limit value for NO2 (47.8 ╬╝g.m-3, in 2009 ÔÇô 58.8 ╬╝g.m-3).
The limit value for 24-hour SO2 concentration was not exceeded in the Czech Republic in 2010. The highest 24-hour concentration was measured at the station Kostomlaty pod Mile┼íovkou (117 ╬╝g.m-3). The 1-hour limit value of SO2 was not exceeded, the highest 1-hour concentration (339 ╬╝g.m-3) was measured at the station Nov├í V├şska u Doma┼í├şna.
Benzo(a)pyrene concentrations were measured in 5 localities, in two of them the target value for the annual average concentration was exceeded (├Üst├ş nad Labem-Z├Ü Pasteurova 2010 ÔÇô 1.6 ng.m-3, 2009 ÔÇô 1.7 ng.m-3, 2008 ÔÇô 1.45 ng.m-3, 2007 ÔÇô 1.34 ng.m-3 and Teplice 2010 ÔÇô 1.2 ng.m-3, 2009 ÔÇô 1.0 ng.m-3). In the 3-year period 2008ÔÇô2010 the target value for ground-level ozone was exceeded only in 1 locality, and namely in Sn─Ť┼żn├şk, of the total number of 11 which measured ozone concentrations in 2010. Similarly as in other parts of the Czech Republic the number of exceedances of the maximum daily 8-hour running average below 120 ╬╝g.m-3decreased. In the ├Üst├ş nad Labem Region the decline was recorded in all localities.
Air pollution situation both in individual months as well as for the whole year 2010 at selected stations of the ├Üst├ş nad Labem Region is depicted in the graphs in II.4.1.36-43. Fig. II.4.1.36 shows the annual course of monthly concentrations of PM10 and the number of exceedances of the 24-hour PM10 limit value in the ├Üst├ş nad Labem Region in 2010. The graph in Fig. II.4.1.39 shows the PM2.5/PM10 ratio and annual average concentrations of PM10 and PM2.5 at the stations in the ├Üst├ş nad Labem Region measuring both fractions. It is apparent that the highest PM2.5/PM10 ratio (about 80 %) was achieved at rural background station Doksany.
In general the 2010 pollutantsĺ concentrations in the ├Üst├ş nad Labem Region were comparable with the previous year, only PM10 concentration showed the increased number of stations with exceedances of the 24-hour limit value. Ozone concentrations showed, similarly as in the whole Czech Republic, the decrease of both the 26th highest maximum daily 8-hour running averages and the number of exceedances of the value 120 ╬╝g.m-3 in the average for 3 years (Fig. II.4.1.42).
Fig. II.4.1.36 The annual course of monthly PM10 concentrations and the number of 24-hour PM10 limit value exceedances, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.37 36th highest 24-hour PM10 concentrations, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.38 The annual course of monthly PM2.5 concentrations, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.39 The annual average concentrations of PM2.5 and PM10, PM2.5/PM10 ratio, ├Üst├ş nad Labem Region 2010
Fig. II.4.1.40 The annual course of average monthly benzo(a)pyrene concentrations, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.41 The annual course of average monthly PM10 and benzo(a)pyrene concentrations, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.42 The annual course of average monthly O3 concentrations, ├Üst├ş nad Labem Region, 2010
Fig. II.4.1.43 The annual course of average monthly NO2 concentrations, ├Üst├ş nad Labem Region, 2010
The trends of SO2, PM10, NO2 and CO annual air pollution characteristics for the period 1996ÔÇô2010 and PM2.5 for the period 2004ÔÇô2010 for the agglomerations Prague, Brno and the Moravian-Silesian Region (further on agglomerations) and for the zone ├Üst├ş nad Labem Region (further on zone) are depicted in Fig. II.4.1.44.
In the period from 1996 to 1999 there was a significant decreasing trend in SO2 and PM10 concentrations in the mentioned agglomerations and the zone. The greatest decrease of SO2 concentrations was recorded in the zone ├Üst├ş nad Labem Region and the greatest decrease of PM10 concentrations was recorded in the agglomerations Moravian-Silesian Region and Prague. In comparison with SO2 and PM10 NO2 concentrations decreased slightly. In the following years 2000ÔÇô2001 the decreasing trend of all pollutants except CO was interrupted and, on the contrary, SO2 concentrations increased in the Moravian-Silesian Region and NO2 concentrations increased in all agglomerations and the zone. Significant increase of PM10 concentrations in 2000ÔÇô2001was recorded mainly in the agglomeration Moravian-Silesian Region. CO concentrations have remained at similar level since 1999.
The increasing trend of PM10 and NO2 concentrations continued in all agglomerations up to 2003 when there were recorded high concentrations of pollutants comparable with the levels measured in 1996. High pollutantsĺ concentrations in 2003 were caused both by unfavourable dispersion conditions in February and December and by subnormal level of precipitation amounts.
In 2004, on the contrary, the ambient air pollution caused by SO2, PM10 a NO2 decreased in the agglomerations and the zone. Starting from 2005 all evaluated areas recorded the increasing trend in NO2, which was confirmed in 2006. As concerns PM10 and PM2.5, there was a similar characteristic increase in 2005, with the steepest progress in the agglomeration Moravian-Silesian Region. In 2006 the increasing trend of PM10 concentrations continued and as concerns PM2.5, this increasing trend was recorded in all monitored areas except for Prague. The increase of pollutantsĺ concentrations in the years 2005 and 2006 is given mainly by deteriorated dispersion conditions. In 2006 these unfavourable meteorological conditions occurred in the whole territory of the Czech Republic. In the ├Üst├ş nad Labem Region and in the Moravian-Silesian Region, on the contrary, there was recorded a very slight decrease of 24-hour PM10 concentrations and the stagnation of annual PM10 concentrations.
In 2007 there was a marked decrease of air pollution caused by SO2, PM10, PM2.5, NO2 and CO in all agglomerations. The steepest decrease is apparent, after the previous increase, in hourly NO2 concentrations in Brno. The decrease of pollutantsĺ concentrations in the ambient air was influenced by more favourable meteorological and dispersion conditions in 2007. In 2008 the decrease of SO2, PM10 and NO2 concentrations continued, but it was not as steep as in the previous year. PM2.5 concentrations mostly stagnated.
In 2009 the PM10 and PM2.5 concentrations in agglomerations increased. The most prominent increase was recorded in the Moravian-Silesian Region. The increase of NO2 concentrations was recorded in Brno, in other agglomerations the concentrations rather stagnated. The increase of concentrations of pollutants was influenced by less favourable meteorological and dispersion conditions, particularly in January, February and December 2009 as compared with the previous year.
In 2010 the increase of concentrations continued in all pollutants in all agglomerations. The highest year-to year increase of PM10 concentrations was recorded in the Moravian-Silesian Region, where the year-to-year increase of average PM10 concentration increased by 10 ╬╝g.m-3; in the remaining agglomerations the year-to-year increase of PM10 was about 2.5 ╬╝g.m-3. The annual average concentrations of PM2.5 also increased in all agglomerations; the highest increase was recorded again in the Moravian-Silesian Region (in the year-to-year comparison by 7.5 ╬╝g.m-3), Further marked increase was recorded in NO2, and namely in the 19th highest hourly concentration in the Moravian-Silesian Region, the second highest increase of NO2 was recorded in the Brno agglomeration. The increase of pollutantsĺ concentrations in 2010 was caused by repeated occurrence of unfavourable meteorological and dispersion conditions in the winter period, both at the beginning of the year (January, February) and at the end of the year (Octobern December).
Fig. II.4.1.44 Trends of SO2, PM10, PM2.5, NO2 and CO annual characteristics in agglomerations, 1996ÔÇô2010
1The assessment (Figs. II.4.1.1 and II.4.1.2) is based on the measurement at 10 stations, which measured for the whole monitored period and provided sufficient number of valid data (Prague 1-n├ím. Republiky (UB), Prague 2-Riegrovy sady (UB), Prague 4-Bran├şk (T), Prague 4-Libu┼í (SUB), Prague 5-Mlyn├í┼Öka (T), Prague 5-Sm├şchov (T), Prague 6-Veleslav├şn (T), Prague 8-Kobylisy (SUB), Prague 9-Vyso─Źany (T), Prague 10-Vr┼íovice (T).
2Detailed information see in: Bla┼żek, Z. ÔÇô ─îernikovsk├Ż, L. ÔÇô Ostro┼żl├şk, T. ÔÇô Voln├Ż, R. ÔÇô Krajny, E. ÔÇô Oťr├│dka, L., 2010. Smogov├í situace v oblasti Ostravsko-Karvinska ve dnech 23.ÔÇô27. ledna 2010. [Smog situation in the Ostrava-Karvin├í area from 23 to 27 January 2010.]. In: Meteorologick├ę zpr├ívy, ro─Ź. 63, ─Ź. 2, s. 33ÔÇô41. ISSN 0026 ÔÇô 1173.