Dear Readers,

Ambient air, especially in the inhabited areas, is contaminated by the pollutants, which are, among others, also of anthropogenic origin. These pollutants have unfavourable impact on human health and the environment as a whole. The basic condition for the implementation of effective remedial measures is the detailed knowledge of background situation. Particularly with regard to this fact the Czech Hydrometeorologcial Institute, authorized by the Ministry of the Environment of the Czech Republic, ensures air quality monitoring and assessment in the territory of the whole Czech Republic. The second reason for ambient air quality monitoring and assessment is the control role of the effectiveness of environmental management and the contribution of the implemented measures. Financial means put in these activities thus bring the improvement of health condition of both the population and the nature.

At the end of the last century the main pollutants included sulphur dioxide, nitrogen oxides and high levels of dust. Thanks to the realized measures concerning the sources in the late 90�s of the 20^th century the air pollution caused by sulphur dioxide significantly decreased. There were recorded lower concentrations also in other pollutants. At present the most serious problem is represented by suspended particles (fractions PM₁₀, PM_2.5 and smaller), the substances bound to them (polycyclic aromatic hydrocarbons, heavy metals), in summer period ground-level ozone and in the vicinity of communications with heavy traffic nitrogen dioxide.

The problem of air pollution is not limited only to the local levels, it goes beyond the boundaries of the states and even continents. Therefore, the broad international cooperation is also necessary, and we can mention in this context the Convention on Long-range Transboundary Air Pollution and the coordination of the measuring and assessement activities within the European Union. The basic document, stipulating the monitoring and assessment of ambient air quality in EU is the Directive No. 2008/50/ES [40]. This directive sets the criteria for the operation of measuring networks and the follow-up procedures in order the results reported by individual member states of the European Union were reliable and comparable. The Directive No. 2007/2/ES (INSPIRE) [41] specifies the requirements for spatial interpretation of data, which make higher demands on the numbers of measuring localities. At the national level the monitoring and assessment of ambient air quality is set by the Clean Air Act No. 86/2002 Coll., [7] as amended, and by the respective implementary regulations.

The Yearbook �Air Pollution in the Czech Republic�, together with the summary annual Tabular Survey �Air Pollution and Atmospheric Deposition in Data, the Czech Republic� published in electronic version, represents the summary overview of data and information on ambient air quality in the territory of the Czech Republic in the respective year. Both outputs are prepared on the basis of data collected in the Air Quality Information System of the Czech Hydrometeorological Institute (ISKO) using other information and mathematical tools. While the Tabular Survey is aimed at objective presentation of verified air pollution data and data on the chemical composition of atmospheric precipitation in individual localities, the Yearbook presents comprehensive information in the form of tables, graphs and maps.

The presented data are processed strictly pursuant to the valid national legislation (Clean Air Act No. 86/2002 Coll., as amended [7] and the Government Order No. 597/2006 Coll. [8] as amended) and pursuant to the requirements of the European Union. The assessment is carried out with regard to the protection of human health and the protection of ecosystems and vegetation. The result maps are the necessary prerequisite for the definition of areas with deteriorated air quality (OZKO) for which programmes aimed at the improvement of air quality or regulatory codes are required by the legislation.

In addition to the information on air pollution loads and atmospheric deposition and their trends, the Yearbook contains also the information on atmospheric emissions in the territory of the Czech Republic and the development of emission inventories in the past years. Not only �classical� pollutants are monitored, but also greenhouse gases. The maps are created with the use of mathematical models, statistical methods and GIS tools in the grid 1 x 1 km.

The Yearbook has been prepared by a team of authors of the CHMI Air Quality Protection Division, including the colleagues from the CHMI branch offices who make their contribution to the assessment of air pollution with regard to their profound regional knowledge. The respective chapters are in charge mainly of the members of Air Quality Information System Department, the Department of Emissions and Sources, the Department of Modelling and Expert�s Reports and the Department of Impact and Risk Assessment, supported by the workers of IDEA-ENVI, Ltd.

Ambient air quality measurement operated by CHMI is ensured by the workers of Air pollution monitoring both at the Headquarters and in the branch offices. Apart from the CHMI measurements results the Air Quality Information System include also outputs provided by the cooperating institutions, and mainly by health institutes, Czech Energetic Works, a.s. (CEZ), Forest Management and Gamekeeping Research Institute (VÚLHM), Czech Geological Survey (ČGS), Water Management Research Institute TGM (VÚV), Hydrobiological Institute (HBÚ), municipal authorities and other contributors. The database also includes the information from the boundary areas of Germany and Poland.

The collection of emission data is ensured in cooperation with the Czech Environmental Inspectorate, the authorities in basic administrative units with enlarged competencies and the Czech Environmental Information Agency (CENIA) which provides the electronic data collection. Further, emission inventories are processed also with the contribution of the experts from ČSÚ, Transport Research Centre (CDV) Brno and Research Institute of Agricultural Technology (VÚZT) Prague. Further necessary background information was submitted by the Military Topographic Institute in Dobruška, Czech Statistical Office (ČSÚ), Road and Motorway Directorate of the Czech Republic (ŘSD) and the Institute of Transportation Engineering of the city of Prague (ÚDI).

The yearbooks on ambient air quality are primarily intended for the bodies and organizations concerned with environmental issues and ambient air protection in the Czech Republic. They are provided to the bodies of state administration (Ministry of the Environment of the Czech Republic, Regional Offices of the Ministry of the Environment, Environmental Departments of the regional authorities and of local authorities in basic administrative units with enlarged competencies, and the Czech Environmental Inspectorate, including its Regional Inspectorates), to all contributors to the ISKO database and further selected entities. Other entities including the general public can use the electronic form at the CHMI website. Both yearbooks are updated and extended every year, with emphasis on information quality, data interpretation and formal aspects, based on our own knowledge and experience and the users� comments.

In conclusion I would like to thank, on behalf of myself and on behalf of the users, to all those who participated in the work related to the preparation of the yearbooks. I believe that the publications will be helpful and valuable for your work. We welcome your suggestions and recommendations for the improvement of the provided services.

Prague, August 2011

RNDr. Jan Macoun, Ph.D.
Deputy Director for Air Quality Protection