II.4.4 Conclusions

The carried out assessment for the year 2007 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 2007 show the following: the limit value for annual average PM₁₀ concentration was exceeded in 0.7 % of the territory of the Czech Republic in 2007, for 24-hour PM₁₀ concentration in 6.3 % of the territory, for annual average NO₂ concentrations 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 6.34 % of the territory of the Czech Republic. The target value for arsenic annual average concentration was exceeded in 0.15 % of the territory of the Czech Republic, for cadmium in 0.02 % of the territory, and for benzo(a)pyrene in 4.9 % of the territory. The target value for at least one pollutant was exceeded in 4.92 % of the territory of the Czech Republic (with the exception of ground-level ozone).
• Air pollution caused by particles (PM₁₀ fraction) continues to exceed the limit values in spite of the fact that the measured concentrations of this pollutant decreased due to favourable meteorological and dispersion conditions as compared with the previous years. The limit value for 24-hour PM₁₀ concentration was exceeded in 2007, most frequently in the Moravian-Silesian Region (Ostrava and Karviná areas) and to a less extent in Olomouc, Central Bohemian, Ústí nad Labem and South Moravian Regions). The limit value for the 24-hour average concentration was exceeded in 6.3 % of the territory (in 2006 in 28.5 % of the territory). The limit value for annual average concentration was exceeded in 0.7 % of the territory of the Czech Republic (in 2006 in 2.3 % of the territory). The area with 24-hour PM₁₀ limit value exceedances was reduced in all zones and agglomerations of the Czech Republic in 2007. In the areas where the PM₁₀ concentrations exceeded the limit values in 2007, live approximately 32 % of the population (in 2006 more than 62 %). The most serious air pollution situation caused by suspended particles is in the Moravian-Silesian Region (Ostrava and 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 2005, pursuant to EU recommendations ensuing from 1999/30/EC Directive, 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 2007 show significant air pollution in the territory of the Moravian-Silesian Region (Ostrava and Karviná area). Of 32 localities, where the PM_2.5 measurements were carried out in 2007, the target 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 5 localities of the Moravian-Silesian Region. 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.
• 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 2007 concentrations exceeded, similarly as in the previous years, the target limit value in the most of the territory of the Czech Republic. About 85 % of its population (97 % 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 2005–2007.
• A lot of towns and villages were assessed, similarly as in the previous year, as the areas with exceeded target value for benzo(a)pyrene – 4.9 % of the territory of the Czech Republic with approximately 51 % of the population
• The current exceedances of the limit values for the PM₁₀ suspended particles and benzo(a)pyrene and the target limit 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.
• 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 and at one station in Brno. 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 2007 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, in Kladno (Švermov, Stehelčeves) and for the first time also in Prague 5-Řeporyje. In spite of the fact that the absolute number of localities with target value exceedances increased, as compared with the year 2006, most of other localities recorded the decrease of the average concentration. About 2 % of the population of the Czech Republic were exposed to the above-the-limit concentrations in 2007.
• The target value for cadmium was exceeded in the Liberec Region, and namely in the locality Tanvald. If this locality has sufficient number of data for annual assessment (measurements without long-term failures), then the value of annual average concentration is exceeding the target value for several years. Higher (but below the limit) concentrations were measured in Ostrava. About 0.06 % of the population were exposed to the above-the-limit concentrations in the Czech Republic in 2007.
• 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 2007.
• The target value for ozone AOT40 for the protection of vegetation was exceeded almost throughout the Czech Republic in 2007 with the exception of larger areas in the territory of the Hradec Králové and Pardubice regions.
• The limit values of SO₂ and NO_x for the protection of vegetation and ecosystems were not exceeded in 2007 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 communication with heaviest traffic runs 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 the agglomeration, 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 Ostrava 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 40 μg.m^-3 prevail the stations from the Ostrava and Karviná area. 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) occurred only in the localities of the Moravian-Silesian Region in 2007. The target annual limit value for annual average concentrations 1 μg.m^-3 are exceeded in larger cities throughout the whole Czech Republic. In the Ostrava and Karviná area, however, there were manifold exceedances of the limit values in 2007. The only localities with exceedances of the limit value for the annual average concentration of benzene plus the margin of tolerance for 2007 (8 μg.m^-3) were, similarly as in the previous years, the stations in Ostrava-Přívoz.

The improvement of air pollution situation recorded in some pollutants in 2007 as compared with the year 2006, is connected mainly with better dispersion and meteorological conditions.

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 mainly in large agglomerations pursuant to the legislative requirements. 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.