II.4.4 Conclusions

The carried out assessment for the year 2008 has taken into account the requirements of the Government Order No. 597/2006. 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 created spatial maps of air pollution characteristics for the year 2008 show the following: the limit value for annual average PM₁₀ concentration was exceeded in 0.44 % of the territory of the Czech Republic in 2008, for 24-hour PM₁₀ concentration in 2.9 % of the territory, for annual average NO₂ concentration in 0.08 % of the territory and for the annual average benzene concentration in 0.02 % of the territory. Air pollution limit value for at least one pollutant was exceeded in 3.04 % of the territory of the Czech Republic. The target value for arsenic annual average concentration was exceeded in 0.2 % of the territory of the Czech Republic, for cadmium in 0.005 % of the territory, and for benzo(a)pyrene in 3.6 % of the territory. The target value for at least one pollutant was exceeded in 3.7 % 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 spite of the fact that the measured concentrations of this pollutant decreased in most localities mainly due to favourable meteorological and dispersion conditions as well as due to the decrease of total emissions of solid substances (REZZO 1) as compared with the previous years. The limit value for 24-hour PM₁₀ concentration was exceeded again most frequently in 2008 in the Moravian-Silesian Region (Ostrava and Karviná areas), to a lesser extent in the South Moravian, Prague, Olomouc, Central Bohemian, Ústí nad Labem, South Bohemian and Zlín Regions). The limit value for the 24-hour average concentration was exceeded in 2.9 % of the territory (in 2006 in 28.5 % of the territory, in 2007 in 6.3 % of the territory). The limit value for annual average concentration was exceeded in 0.44 % of the territory of the Czech Republic (in 2006 in 2.3 % of the territory, in 2007 in 0.7 % of the territory). In the areas where the PM₁₀ concentrations exceeded the limit values in 2008, live approximately 15 % of the population (in 2006 it was the territory with more than 62 %, in 2007 with 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 2008 show significant air pollution in the territory of the Moravian-Silesian Region (Ostrava and Karviná area). Of 35 localities, where the PM_2.5 measurements were carried out in 2008, the target 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 9 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 6 localities in total measured above-the-limit concentration. Other stations with the exceedance of the PM_2.5 limit value concentrations are in the Brno agglomeration.

• The limit values for the protection of health for 24-hour and hourly SO₂ concentrations were not exceeded in 2008 at any monitoring station in the Czech Republic.

• The concentration of the ground-level ozone – the �summer� pollutant of photochemical origin – influences the character of the weather in the warm half of the year. The 2008 concentrations exceeded, similarly as in the previous years, the target value in the most of the territory of the Czech Republic. About 69 % of its population (almost 94 % of the territory) 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 2006–2008. As compared with the previous year almost 85 % of localities reported the decrease of exceedances of the number of the value 120 μg.m^-3 in the assessed three-year period 2006–2008 which is probably connected with the decrease of the concentrations of the ground-level ozone precursors.

• A lot of towns and villages were assessed, similarly as in 2007, as the areas with exceeded target value for benzo(a)pyrene, and namely 3.6 % of the territory of the Czech Republic with approximately 42 % of the population. As compared with the year 2007, however, the annual averages decreased approx. in two thirds of localities and during the recent three years there has also been an apparent decrease of the relative number of localities with the exceeded limit value.

• The current exceedances of the limit values for the PM₁₀ suspended particles and benzo(a)pyrene and the target values 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 5 stations in the Capital City of Prague, in two localities in Brno and 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 2008 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 Prague (Prague 5-Řeporyje), in Kladno (Kladno-Vrapice, Kladno-Švermov, Stehelčeves) and in Ostrava (Ostrava-Mariánské Hory, Ostrava-Bartovice) in 2008. In spite of the fact that the number of localities with exceedances increased as compared with 2007, the annual average concentration decreased in approx. two thirds of localities. About 2 % of the population of the Czech Republic were exposed to the above-the-limit concentrations in 2008.

• The target value for cadmium was exceeded for the first time in 2008 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, the limit value for annual average concentration of lead and for the maximum 8-hour concentration of CO were not exceeded in 2008.

•  The target value for ozone AOT40 for the protection of vegetation was exceeded almost throughout the Czech Republic in 2008 with the exception of larger areas in the territory of the Hradec Králové, Pardubice and Moravian-Silesian regions.

• The limit values of SO₂ and NO_x for the protection of vegetation and ecosystems were not exceeded in 2008 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 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 target 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 annual limit value for annual average benzo(a)pyrene concentration 1 ng.m^-3 is continuously exceeded in most large settlements throughout the whole Czech Republic. However, it can be expected that this limit value is exceeded also in smaller settlements). In the Ostrava and Karviná area and in Kladno there were recorded even manifold exceedances of the limit values in 2008. 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.