AIR POLLUTION IN THE CZECH REPUBLIC IN 2005

Czech Hydrometeorological Institute - Air Quality Protection Division




II.4.1 Agglomerations

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) was treated with more attention in 2005. In addition to the above agglomerations, special attention is paid to the zone Ústí nad Labem Region due to the recorded above-the-limit concentrations.

II.4.1.1 Prague

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 exceedences are connected with relatively high traffic loads.
In 2005 the PM10 concentrations were monitored in Prague in 14 CHMI localities. The highest numbers of exceedences of 24-hour average concentration 50 μg.m-3 were recorded at the following stations: AMS Prague 2-Legerova (101x), Prague 8-Karlín (88x) and Prague 9-Vysočany (78x). Of the total number of 13 AMS stations 12 stations recorded 24-hour PM10 limit value exceedence. Exceedences of the annual limit value of PM10 (40 μg.m-3) was recorded at AMS Prague 2-Legerova (45 μg.m-3).
PM2.5 concentrations were monitored in 5 CHMI localities in 2005. In spite of the fact the PM2.5 air pollution limit value is not yet valid, the comparison of the measured concentrations with the proposed limit value (25 μg.m-3, annual average) is very interesting. The annual average concentrations in Prague localities are as follows: Prague 5-Smíchov 30.5 μg.m-3, Prague 9-Vysočany 24.9 μg.m-3, Prague 4-Libuš 24.6 μg.m-3 and Prague 5-Mlynářka 23.2 μg.m-3. It is quite evident that if the proposed limit value for PM2.5 fraction was valid, it would be exceeded at 1 Prague station and at 3 stations the measured levels would be very close to it.
NO2 concentrations were measured in 15 localities in Prague in 2005. The locality Prague 2-Legerova exceeded both the hourly limit value and the hourly limit value increased by the margin of tolerance. The value of 200 μg.m-3 was exceeded 174x, the value of the limit increased by the margin of tolerance (200+50 μg.m-3) 36x. The exceedence of the value of 250 μg.m-3 was measured 1x at the AMS station Prague 5-Smíchov. The hourly concentration 200 μg.m-3 was exceeded also in several other localities, nevertheless the number of exceedences remained far below the tolerated number of exceedences.
The exceedence of the annual air pollution limit value (increased by the margin of tolerance) for NO2 (40+10 μg.m-3) was recorded at the AMS Prague 2-Legerova (75 μg.m-3) and also in the following ZÚ localities: Svornosti in Prague 5 (76 μg.m-3), Sokolovská in Prague 8 (73 μg.m-3) and Jasmínová in Prague 10 (53 μg.m-3).
Another problem is caused by above-the-limit benzo(a)pyrene concentrations which exceeded the target air pollution limit value at all (3) stations which measured it in Prague, and namely Prague 10-Šrobárova, Prague 5-Smíchov, Prague 4-Libuš).
The results of the measured concentrations of PM10, NO2 and benzo(a)pyrene suggest to the necessity to find the solution for the traffic situation within the agglomeration.
The exceedences of the target air pollution limit value for the ground-level ozone was also recorded. It was exceeded in 6 of 9 localities in Prague, which have carried out the measurements in recent three years at least for the period of one year (pursuant to the definition of the target air pollution limit value in the Government Order).

II.4.1.2 Brno

In Brno, similarly as in Prague, the ambient air pollution problems are connected with high population density of this area.
PM10 concentrations were measured in 2 localities in 2005. The exceedence of the PM10 24-hour air pollution limit value was recorded at AMS Brno-střed which is located in the city centre in the immediate vicinity of the crossroad of two frequented communications. The tolerated number of exceedence of the value 50 μg.m-3 is 35x in total; the measurements at this station, however, recorded 122 cases of exceedence. Air pollution limit value was further recorded in the localities Brno-Tuřany and Brno-Kroftova which is also influenced by traffic. The number of exceedences of the value 50 μg.m-3 at these stations was measured 59x and 46x, respectively. The AMS Brno-střed recorded also the PM10 annual air pollution limit value.
The only locality in Brno measuring the PM2.5 fraction in 2005, and namely Brno-Tuřany, would exceed the proposed air pollution limit value, as it recorded the annual average 26.3 μg.m-3.
The NO2 annual air pollution limit value was exceeded in both localities (Brno-střed and Brno-Kroftova) which measure NO2 in Brno. The air pollution limit value increased by the margin of tolerance was not exceeded. In 2005 also the target air pollution limit value for benzo(a)pyrene was exceeded in both localities (Brno-Kroftova and Brno-Húskova), which measure this pollutant in Brno.
The concentrations of ground-level ozone were measured in 2 localities in 2005 of which one (Brno-Tuřany) exceeded the target air pollution limit value for ground-level ozone. The deadline for achieving this limit value is 1.1.2010.

II.4.1.3 The Moravian-Silesian Region

The ambient air pollution in the agglomeration Moravian-Silesian Region is connected, in addition to high population density, also with high concentration of industry, and namely in the following cities: Ostrava, Karviná, Havířov, Český Těšín and Třinec.
In 2005 PM10 concentrations were monitored in 16 localities (14 CHMI, 1 ZÚ and 1 MÚTř) in the agglomeration Moravian-Silesian Region. The exceedence of the PM10 24-hour air pollution limit value was reached most frequently at the stations in the districts Karviná and Ostrava-město, then in several parts of the districts Frýdek-Místek, Nový Jičín and Opava. The highest number of exceedences of the value of 50 μg.m-3 was recorded in the following stations: AMS Český Těšín (170x), Orlová (162x), Ostrava-Přívoz (160x), Bohumín (159x), Havířov (155x), Karviná (149x), Ostrava-Českobratrská (144x), Věřňovice in the district Karviná (126x), Frýdek-Místek (122x) and Ostrava-Zábřeh (120x). In total, 19 localities of the Moravian-Silesian Region exceeded the PM10 24-hour limit value.
The highest exceedence of the PM10 annual air pollution limit value (40 μg.m-3) was recorded also in the above districts. The highest annual average was recorded at the following AMS stations: Bohumín (62 μg.m-3), Český Těšín (60 μg.m-3), Orlová (59 μg.m-3), Ostrava-Přívoz (58 μg.m-3), Havířov (56 μg.m-3), Ostrava-Českobratrská (55 μg.m-3), Věřňovice (55 μg.m-3), Karviná (54 μg.m-3) and Ostrava-Fifejdy (50 μg.m-3). Air pollution limit value for annual average was exceeded in 17 localities in this region.
The localities which measured PM2.5 fraction in 2005 in the Moravian-Silesian Region rank among the top localities as for the reached concentrations within the Czech Republic. In the locality Věřnovice the annual average amounted to 45 μg.m-3, in Ostrava-Přívoz 43.3 μg.m-3, in Ostrava-Zábřeh 38.7 μg.m-3 and in Ostrava-Poruba 34.1 μg.m-3. It is evident that all localities would exceed the proposed air pollution limit value.
NO2 concentrations were measured in total in 19 localities in 2005 (16 CHMI, 1 MUTř, 1 ZÚ and 1 ČEZ). The AMS Ostrava-Českobratrská (hot spot) recorded the NO2 annual air pollution limit value exceedence; the air pollution limit value increased by the margin of tolerance was not exceeded.
The highest benzo(a)pyrene concentrations in the Czech Republic in 2005 occurred right here, in the Moravian-Silesian Region. The above-the-limit concentrations were measured in all 4 localities which measured this pollutant in 2005 (Ostrava-Přívoz ZÚ, Český Těšín, Ostrava-Poruba/CHMI, Karviná ZÚ).
Another problem is caused by the high benzene concentrations which exceeded the air pollution limit value (as the only ones in the Czech Republic) in both localities with the highest industrial loads, i.e. Ostrava-Přívoz (ZÚ and CHMI). In other localities the air pollution limit value was not exceeded. In 2005 benzene concentrations were monitored in 5 localities of the Moravian-Silesian Region.
In 5 localities (of the total number of 7) the target air pollution limit values for ground-level ozone was exceeded as well, mainly in localities with lower traffic loads, and namely: Bílý kříž, Červená, Ostrava-Fifejdy, Studénky, Karviná.
Arsenic concentrations (5.8 ng.m-3) close to the limit value, nevertheless not exceeding it, were recorded at the most loaded station in this area Ostrava-Přívoz ZÚ.
The following text presents the detailed description of unfavourable situation of February 2005 which resulted in significant increase of air pollution concentrations in the Moravian-Silesian Region.

Unfavourable air pollution situation in the Moravian-Silesian agglomeration in February 2005

In early February 2005 the area of northern Moravia and Silesia was influenced by the anticyclone with the centre above Russia. Very cold air started to flow to the area which resulted in temperature inversion. Between 5 and 9 February the weather was mostly clear and sunny without precipitation and very cold; the lowest night temperatures dropped up to –20 C. The meteorological situation was markedly changed on 10 February when the frontal system moved from the west bringing the change of weather. The temperatures increased, the inversion disappeared and snowfall began during the night. Up to 13 February the weather was very warm, snow or mixed precipitation was recorded.
Due to the temperature inversion and the decline of airflow velocity, the dispersion conditions deteriorated and pollutants concentrations in the ambient air markedly increased. Most significant increase was recorded in concentrations of PM10 suspended particles. On 1 and 2 February PM10 concentrations remained in most cases below the 24-hour limit value 50 μg.m-3. Beginning from 3 February, however, they were increasing and on 6–8 February the exceedences of the limit value of manifold level were recorded. The worst air pollution situation was on 6 and 7 February when the 24-hour PM10 concentrations ranged between 131 μg.m-3 and 429 μg.m-3. With the disappearing anticyclone the concentrations dropped after 8 February, but did not drop below the limit value until 12 February (Fig. II.4.7 shows the concentration values measured at automated monitoring stations (AMS) of the National air pollution network.)
The described situation documents quite clearly the dominant influence of meteorological dispersion conditions on the current ambient air quality. Fig. II.4.8 shows
- wind velocity in the elevation of 200 m and 36 m in Ostrava and 10 m at AMS Karviná,
- vertical temperature gradient of air between meteorological stations Mošnov (251 m a.s.l.) and Lysá hora (1324 m a.s.l.) ,
- average hourly PM10 concentration measured at the stations in the area and 95th percentile of these concentrations.
With the decrease of wind velocity and stronger inversion (characterized by air temperature gradient in the picture) PM10 concentrations markedly increased from 5 February. In spite of temporary break in temperature inversion between Mošnov and Lysá hora, there did not occur any significant decline of PM10 concentrations during the daily hours on 6 and 7 February, as unfavourable dispersion conditions near the ground persisted. On 8 February, during the day there was a temporary decline of current concentrations as the influence of the anticyclone was already weaker and the wind velocity was higher. In the afternoon hours on 9 February when simultaneously, airflow increased and temperature inversion weakened, the PM10 concentrations finally decreased.
The unfavourable air pollution situation of February 2005 illustrates again that the most burning problem in the Ostrava area is air pollution caused by suspended particles, not only within the yearly assessment. The long lasting unfavourable conditions for the dispersion of pollutants in the ambient air result in the increase of the PM10 suspended particles concentrations up to several times higher than is the daily air pollution limit value. The relevance of the problem is stressed by the fact that other pollutants are bound to the suspended particles.

II.4.1.4 Other areas with air pollution loads with higher density of population

The Ústí nad Labem Zone

The Communication of the Ministry of Environment of the Czech Republic defines the Ústí nad Labem Region as a zone. This area has high population density with above-the-limit concentrations of a number of pollutants.
PM10 concentrations were measured in 14 CHMI localities in the Ústí nad Labem Region. The exceedences of the 24-hour air pollution limit value for PM10 occurred mostly in the Most and Ústí nad Labem districts. The highest numbers of exceedence of the value 50 μg.m-3 were recorded at the following stations: Most (118x), Ústí n.L.-město (105x), Teplice (98x), Horní Jiřetín in Most district (89x), Děčín (87x), Tušimice in Chomutov district (80x), Ústí n.L.-Všebořická (79x), Lom in Most district (78x), Litoměřice (69x) and Chomutov (59x). In total, 14 localities in the Ústí nad Labem Region exceeded the PM10 24-hour limit value. The exceedence of the PM10 annual limit value was recorded at the following stations: Most (43 μg.m-3), Horní Jiřetín (42 μg.m-3), Ústí n.L.-město (42 μg.m-3) and Teplice (41 μg.m-3).
The annual average PM2.5 concentration in the locality Teplice reached the value of 27.1 μg.m-3; it would thus exceed the proposed limit value. The annual average concentration reached 24.0 μg.m-3 in Most and 22.5 μg.m-3.in Ústí n.L. Kočkov.
In 2005 NO2 concentrations were monitored in 24 localities in the Ústí nad Labem Region (14 CHMI + 10 of other organizations). The ZÚ station Děčín, which is significantly influenced by traffic, the annual air pollution limit value of NO2 was exceeded. In case of the air pollution limit value increased by the margin of tolerance the exceedence was close above the limit.
Air pollution limit values for SO2 (hourly and 24-hour) were not exceeded. Occasionally the exceedences of hourly concentration 350 μg.m-3 or of 24-hour average concentration 125 μg.m-3 occurred, in most cases at the stations operated by ČEZ. The exceedences, however, remained within the tolerated number of exceedences.
The target air pollution limit value for benzo(a)pyrene was exceeded at one of the two stations in Ústí nad Labem which measured this pollutant (Ústí nad Labem-ZÚ, Pasteurova); other exceedences occurred in Teplice and Most. In total benzo(a)pyrene concentrations were monitored in 4 localities.
Several of the total number of 6 localities monitoring benzene concentrations in the Ústí nad Labem Region, recorded increased concentrations, nevertheless the limit value was not exceeded.
The target air pollution limit value for ground-level ozone was markedly exceeded similarly as in other parts of the Czech Republic, and mainly at the stations with lower traffic loads. The exceedence was recorded in 7 localities of the total number of 12 localities.

4.1.5 Trends of annual air pollution characteristics of SO2, PM10 and NO2 for the period 1996–2005

Fig II.4.9 shows the trends of SO2, PM10 and NO2 annual air pollution characteristics in 1995–2005 for the following agglomerations: Prague, Brno and Moravian-Silesian Region and for the zone Ústí nad Labem Region. Up to 1999 there was a significant decreasing trend in SO2 and PM10 concentrations in the agglomerations, the NO2 concentrations decreased only slightly. In 2001 the decreasing trend was interrupted and, on the contrary, the SO2 and NO2 concentrations slightly increased; PM10 concentrations increased significantly, mainly in the Ostrava agglomeration. In 2004, on the contrary, concentrations of all pollutants monitored in the agglomerations decreased and SO2 concentrations slightly increased in the Ústí nad Labem Region. In 2005 PM10 and NO2 air pollution returned to the increasing trend, with the steepest progress in the Moravian-Silesian Region. In case of Ústí nad Labem Region only PM10 concentrations were increasing; NO2 concentrations, on the contrary, recorded a slight decline.


Fig. II.4.1 Field of the annual concentration of NO2 (3-D image), Prague agglomeration, 2005


Fig. II.4.2 Field of the annual concentration of benzo(a)pyrene (3-D image), Prague agglomeration, 2005


Fig. II.4.3 Field of the annual concentration of NO2 (3-D image), Brno agglomeration, 2005


Fig. II.4.4 Field of the annual concentration of benzo(a)pyrene (3-D image), Brno agglomeration, 2005


Fig. II.4.5 Field of the annual concentration of NO2 (3-D image), Moravian-Silesian agglomeration, 2005


Fig. II.4.6 Field of the annual concentration of benzo(a)pyrene (3-D image), Moravian-Silesian agglomeration, 2005


Fig. II.4.7 Average 24-hour PM10 concentrations, Moravian-Silesian agglomeration, February 2005


Fig. II.4.8 Interdependency between PM10 ambient air pollution and dispersion meteorological conditions


Fig. II.4.9 Trends of SO2, PM10 and NO2 annual characteristics in agglomerations, 1996–2005