II.4.4 Conclusions

The carried out assessment for the year 2009 has taken into account the requirements of the Government Order No. 597/2006 Coll. The following problems were indicated with regard to meeting the deadlines of limit values (target values) set by the national legislation on the protection of ambient air:

• The spatial maps of air pollution characteristics for the year 2009 show the following: the limit value for annual average PM₁₀ concentration was exceeded in 0.54 % of the territory of the Czech Republic in 2009, for 24-hour PM₁₀ concentration in 4.42 % of the territory, for annual average NO₂ concentration in 0.03 % of the territory, for 24-hour concentration of SO₂ in 0.0013 % of the territory and for the annual average benzene concentration in 0.006 % of the territory. Air pollution limit value for at least one pollutant was exceeded in 4.44 % of the territory of the Czech Republic. The target value for arsenic annual average concentration was exceeded in 0.02 % of the territory of the Czech Republic and for benzo(a)pyrene in 2.31 % of the territory. The target value for at least one pollutant was exceeded in 2.3 % of the territory of the Czech Republic (with the exception of ground-level ozone).

• The levels of air pollution caused by PM₁₀ particles continue to exceed the limit values. In 2009 there was recorded certain increase of the measured concentrations of this pollutant as compared with the previous year in most localities mainly due to less favourable meteorological and dispersion conditions in January, February and December 2009. The limit value for 24-hour PM₁₀ concentration was exceeded again most frequently in 2009 in the Moravian-Silesian Region (Ostrava and Karviná areas, to a lesser extent in the South Moravian, Central Bohemian, Olomouc, Ústí nad Labem, Zlín, South Bohemian regions and in Prague). The limit value for the 24-hour average concentration was exceeded in 4.4 % of the territory (in 2008 in 2.9 % of the territory, in 2007 in 6.3 % of the territory. The limit value for annual average concentration was exceeded in 0.54 % of the territory of the Czech Republic (in 2008 in 0.44 % of the territory, in 2007 in 0.7 % of the territory). In the areas where the PM₁₀ concentrations exceeded the limit values in 2009, live approximately 18 % of the population (in 2008 it was 15 % of the population, in 2007 32 % of the population). The most serious air pollution situation caused by suspended particles remains in the agglomeration Moravian-Silesian Region (Ostrava-Karviná area). This is caused by the fact that in this area, in addition to transport and local sources, which are the main emission sources of suspended particles also in other regions, significant contribution is made by further emission sources, and mainly metallurgy and fuel processing. Air pollution loads of this area are influenced also by regional transfer from the sources in Poland (heavily industrialized Katowice area).

• In 2004 the monitoring of the concentration of the fine PM_2.5 fraction started to be monitored in the Czech Republic. The prevailing source of PM_2.5 fraction emissions are combustion processes, producing secondary particles originating as a result of chemical reactions between the gaseous compounds and condensation of hot gases and vapour. The measurement results for the year 2009 show significant air pollution in the territory of the Moravian-Silesian Region (Ostrava and Karviná area). Of 36 localities, where the PM_2.5 measurements were carried out in 2009, the limit value for annual concentration (pursuant to the Directive 2008/50/EC of the European Parliament which will be implemented into the Czech legislation), was exceeded in 10 localities. The highest annual average concentrations of PM_2.5 were recorded, similarly as in case of PM₁₀, in the localities in the Ostrava-Karviná area, where the above-the-limit concentration were measured in 7 localities in total. Two stations with the exceedance of the PM_2.5 limit value concentrations are in the Brno agglomeration and one in the Olomouc Region (Přerov).

• The limit value for the protection of health for hourly SO₂ concentrations were not exceeded in 2009 at any monitoring station in the Czech Republic, the 24-hour limit value of SO₂, on the contrary, was exceeded at one monitoring station (Teplice-ZÚ).

• The concentration of the ground-level ozone – the �summer� pollutant of photochemical origin – is influenced by the character of the weather in the warm half of the year. The 2009 concentrations decreased in comparison with the previous years. The target value was exceeded in 47 % of the territory of the Czech Republic. About 23 % of its population were in average exposed to the concentrations of the ground-level ozone exceeding the target values for the protection of human health in the assessed period 2007–2009. As compared with the previous three-year period almost 88 % of localities reported the decrease of the number of exceedances of the value 120 μg.m^-3 in the assessed three-year period 2007–2009. This decrease is probably connected with a slight decrease of maximum temperatures during the summer period (April–September) 2009 and further with a certain decrease of the concentrations of ozone precursors (mainly NO₂) as compared with the year 2006, which was not included in the assessed three-year period 2007–2009.

• A lot of towns and villages were assessed, similarly as in 2008, as the areas with exceeded target value for benzo(a)pyrene, and namely 2.31 % of the territory of the Czech Republic with approximately 35.5 % of the population. Against the year 2008, the annual averages were comparable in 2009.

• The current exceedances of the limit values for the PM₁₀ suspended particles and benzo(a)pyrene and the limit value for fine PM_2.5 particles pursuant to the Directive 2008/50/EC, can be regarded as alarming, especially in connection with their serious impacts on human health. It is supposed that both the increased and exceeding concentrations of benzo(a)pyrene occur also in the towns and villages where there is no measurement, and namely due to emissions from local sources (combustion in households).

• The increasing traffic loads result in exceedances of the limit values increased by the margin of tolerance for NO₂ in the localities exposed to traffic, and namely at 3 stations in the Capital City of Prague and in Brno, and in two localities in the Ústí nad Labem Region (Ústí n.L. and Děčín) and in one in Ostrava. The limit value exceedances can be expected also in other similarly traffic loaded sites, where there are no measurements applied.

• The measurements for the year 2009 indicate that benzene limit value is exceeded in Ostrava again, mainly due to emissions from coking plants.

• The target value for annual average concentrations of arsenic was exceeded in Ostrava (Ostrava-Mariánské Hory) and in Kladno (Kladno-Švermov) in 2009. About 0.25 % of the population of the Czech Republic were exposed to the above-the-limit concentrations in 2009.

• The target value for cadmium was exceeded for the first time in 2009 in Ostrava, in the locality Ostrava-Mariánské Hory. On the contrary, the decrease of concentration was recorded in the Liberec Region in the locality Tanvald, where in a number of previous years the above-the-limit concentrations were recorded. About 0.25 % of the population were exposed to the above-the-limit concentrations in the Czech Republic in 2008.

• The target value for the annual average concentration of nickel and cadmium and the limit values for annual average concentration of lead and for the maximum 8-hour concentration of CO were not exceeded in 2009.

• The target value for ozone AOT40 for the protection of vegetation was exceeded almost throughout the Czech Republic in 2009.

• The limit values of SO₂ and NO_x for the protection of vegetation and ecosystems were not exceeded in 2009 at any rural monitoring station.

• In agglomerations, the problem of the increased pollutants� concentrations is particularly serious and a great number of people are affected due to the high population density. The exceedance of limit values in the Capital City of Prague is connected mainly with the significant traffic load and also with the fact that the communications with heaviest traffic run directly through the city centre. The results of the measured concentrations of PM₁₀, NO₂ and benzo(a)pyrene still suggest to find the solution of this absolutely unsatisfactory traffic situation in Prague, where the above-the-limit concentrations impact considerable share of the population. Similar situation can be found in the localities with traffic loads in Brno. In the Moravian-Silesian Region significant contribution to air pollution, in addition to transport, is made by metallurgy and fuel processing industry, and mainly in the Ostrava-Karviná area, which is the most polluted locality in the Czech Republic.

• In the overview of the most polluted localities of the Czech Republic by suspended particles of PM₁₀ fraction with the annual limit value above 40 μg.m^-3 prevail the stations from the Ostrava and Karviná area. Similar situation is in the exceedance of the value for annual average concentrations of fine particles of PM_2.5 fraction pursuant to the Directive 2008/50/EC (25 μg.m^-3). The target limit value for annual average benzo(a)pyrene concentration 1 ng.m^-3 is continuously exceeded in a number of large settlements throughout the whole Czech Republic. However, it can be expected that this limit value is exceeded also in smaller settlements. In many localities (mainly in the Moravian-Silesian Region and in Kladno) there were recorded even manifold exceedances of the limit values in 2009. The only locality with the exceedance of the annual limit value for benzene (5 μg.m^-3) was, similarly as in the previous years, the station in Ostrava-Přívoz.

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

Relatively high contribution of secondary particles show that significant decrease of PM₁₀ concentrations will be possible by further decreasing of emission of the components causing the creation of the fraction of secondary particles in atmospheric aerosol. This demands mainly the decreasing of NO_x and VOC emissions in compliance with the requirement to meet the national emission ceilings. Further decrease of emissions, mainly NO_x emissions but also VOC emissions on a large scale, is the only possible way how to decrease the loads caused by exceeding ground-level ozone concentrations.

The assessment of the ambient air pollution is based on the measurement which is focused, pursuant to the legislative requirements, mainly in large cities. The expert estimates and the results of the published works show, however, that it is highly probable that both the increased and above-the-limit concentrations of a number of pollutants occur also in a number of small towns and villages where there is no air pollution monitoring carried out and where lives a relatively large share of population of the Czech Republic. The substances concerned are mainly as follows: suspended particles, polycyclic aromatic hydrocarbons and heavy metals. The essential role in air pollution is played by geomorphological conditions, traffic loads and the type of heating. Due to burning wood and coal there occur increased emissions of particles, PAH and heavy metals. Moreover, by burning refuse in local furnaces dangerous dioxins are emitted in the ambient air.