II.4.4 Conclusions

The carried out assessment for the year 2010 has taken into account the requirements of the Government Order No. 597/2006 Coll., as amended. 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 2010 show the following: the limit value for annual average PM₁₀ concentration was exceeded in 1.85 % of the territory of the Czech Republic in 2010, for 24-hour PM₁₀ concentration in 21.21 % of the territory, for annual average NO₂ concentration in 0.03 % of the territory, and for the annual average benzene concentration in 0.001 % of the territory. Air pollution limit value for at least one pollutant was exceeded in 21.21 % of the territory of the Czech Republic. The target value for arsenic annual average concentration was exceeded in 0.008 % of the territory of the Czech Republic and for benzo(a)pyrene in 14.47 % of the territory. The target value for at least one pollutant was exceeded in 14.47 % 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 2010 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, October and December 2010 and due to the coldest heating season for the recent 10 years (Fig. I.1.3). The limit value for 24-hour PM₁₀ concentration was exceeded in all localities in the agglomeration Moravian-Silesian Region and in more than half or most of the localities in the zones Ústí nad Labem, Central Bohemian, Olomouc and Zlín regions and in the agglomerations Prague and Brno. The limit value for the 24-hour average concentration was exceeded in 21.21 % of the territory (in 2009 in 4.4 % of the territory, in 2008 in 2.9 % of the territory). The limit value for annual average concentration was exceeded in 1.85 % of the territory of the Czech Republic (in 2009 in 0.54 % of the territory, in 2008 in 0.44 % of the territory). In the areas where the PM₁₀ concentrations exceeded the limit values in 2010, live approximately 48 % of the population (in 2009 it was 18 % of the population, in 2008 15 % 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 2010 show significant air pollution in the territory of the Moravian-Silesian Region (Ostrava and Karviná area). Out of 38 localities, where the PM_2.5 measurements were carried out in 2010, the target value for annual concentration was exceeded in 12 localities, and namely in 7 localities in the Ostrava-Karviná area, in 3 localities in the Brno agglomeration, in the locality Přerov in the zone Olomouc Region, and in the locality Zlín in the zone Zlín Region.

• 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 2010 concentrations decreased again in comparison with the previous years. The target value was exceeded in 10.26 % of the territory of the Czech Republic. About 2.1 % 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 2008–2010. As compared with the previous three-year period almost 74 % of localities reported the decrease of the number of exceedances of the value 120 μg.m^-3 in the assessed three-year period 2008–2010. This decrease is probably connected with a slight decrease of maximum temperatures and the values of global solar radiation during the period April–September 2010 in comparison with the same period of the year 2007.

• A lot of towns and villages were assessed, similarly as in 2009, as the areas with exceeded target value for benzo(a)pyrene, and namely 14.47 % of the territory of the Czech Republic with approximately 65 % of the population. In comparison with the year 2009 there was recorded a significant growth of the area of the territory of the Czech Republic with the exceedance of the target value, and particularly the growth of the number of affected inhabitants. In 2009 the respective numbers were 2.31 % of the territory and 35.5 % of inhabitants.

• 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 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 for NO₂ in the localities exposed to traffic, and namely at 10 stations in Prague, Brno and Ostrava. The limit value exceedances can be expected also in other similarly traffic loaded sites, where there are no measurements applied. In 2010, as compared with 2009, a slight increase of annual average concentration was recorded in more than 70 % of localities.

• The measurements for the year 2010 indicate that benzene limit value is exceeded in Ostrava again, mainly due to emissions from coking plants.

• The limit value for the protection of human health for 24-hour and hourly SO₂ concentrations was not exceeded in 2010 at any monitoring station in the Czech Republic, but the concentrations slightly increased, as compared with the year 2009, in more than half of the localities, especially in the Ostrava-Karviná area.

• The target value for annual average concentrations of arsenic was exceeded in two localities in the Kladno area (Stehelčeves, Kladno-Švermov) in 2010. About 0.06 % of the population of the Czech Republic inhabiting 0.008 % of the territory of the Czech Republic were exposed to the above-the-limit concentrations in 2010.

• 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 2010.

• The target value for ozone AOT40 for the protection of vegetation was exceeded in most territory of the Czech Republic in 2010 (the 5-year assessed period 2006–2010), nevertheless in comparison with the previous assessed period for the years 2005–2009 the areas with exceedances decreased in Prague and in the Central Bohemian, Ústí nad Labem, Hradec Králové, Moravian-Silesian, Pardubice and Olomouc regions.

• The limit values for the annual average concentration of NO_x and SO₂ for the protection of vegetation and ecosystems were not exceeded in 2010 at any rural locality. The limit value for the winter average of SO₂ was exceeded for the first time after 6 years, and namely in the locality Komáří Vížka.

• 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.

The overview of the most polluted localities of the Czech Republic with exceedances of PM₁₀ fraction annual limit value (40 μg.m^-3) includes mainly the areas of the Moravian-Silesian Region. Similar situation is in the exceedance of the target value for annual average concentrations of fine particles of PM_2.5 fraction. The annual average concentrations of benzo(a)pyrene continuously exceed the annual target value 1 ng.m^-3 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 2010.

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 NH₃ and VOC), 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 shows that significant decrease of PM₁₀ concentrations will be possible by further decreasing of emission of the components causing the creation of secondary particles ( NO_x, SO₂, NH₃ and VOC). 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 suspended particles and polycyclic aromatic hydrocarbons. The essential role in air pollution is played by geomorphological conditions, meteorological conditions, traffic loads and the type of heating, especially in the appliances not suitable for the given type of fuel. 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.