The concept of air pollution (emissions) encompasses an extensive number of processes that lead to emissions of pollutants into the air. Air pollution sources are natural or anthropogenic in origin, where the borderline between these two types is not always unambiguous. Natural sources include volcanic activity, fires, pollution production by plants, etc. Anthropogenic sources are a result of human activity. Primary air pollution is understood to correspond to the emission of pollutants into the air directly from their sources, while secondary pollutants are formed as a result of physical-chemical reactions in the atmosphere (ozone, secondary SPM, most NO2 etc.).

CHMI evaluates the level of air pollution under authorisation by the Ministry of the Environment for primary pollutants and greenhouse gases. The basic documents for this evaluation consist in the "emission inventories", which combine direct collection of data reported by the operators of sources with model calculations of data reported by the operators of sources or determined in the context of statistical studies performed primarily by the Czech Statistical Office. The resultant emission inventories are presented in the form of emission balances in sectoral and territorial classifications1.

Emissions of air pollutants

The emission database (Register of Air Pollution Emissions and Sources – REZZO) serves for filing and presentation of data on stationary and mobile pollution sources and, pursuant to Article 7 of the Air Protection Act, is part of the Air Quality Information System (AQIS – ISKO) observed by CHMI. From the viewpoint of the means of monitoring emissions, air pollution sources are divided into individually monitored sources and collectively monitored sources. Since 2013, new REZZO categorisation has been valid in connection with changes in the categorisation of sources pursuant to Annex No. 2 of the Air Protection Act (Table II.1).

International reporting of summary emission data is based on sectoral classification of sources following from the Nomenclature for Reporting Codes - NFR. The main groups of sources consist in combustion sources, including transport (NFR 1), technological sources without combustion, termed process emissions (NFR 2), sources using solvents (B+NFR 2D), agricultural activities including livestock farming (NFR 3B) and waste management (NFR 5). Not only emissions of main pollutants are reported, but also emissions of PM10 and PM2.5, heavy metals and POP2.

Emissions from individually monitored sources in the Czech Republic

The sources listed in Annex No. 2 of the Air Protection Act are monitored individually. Pursuant to Article 17 (3) c), the operators of these sources are obliged to keep operating records of constant and variable data on stationary sources, describing the source and its operation, and also data on inputs and outputs from these sources. They are also obliged to annually report information on the summary operating records (SPE) through the Integrated system of fulfilling reporting obligations (ISPOP). ISPOP data are then collected in the REZZO 1 and REZZO 2 databases. Collection of data for the previous year takes place from January to the end of March. Reported data are available at the beginning of April and control and processing of the submitted reports then take place in the following months, supplemented by requests for correction of erroneous data3.

For international reporting and air quality modelling, pollutant emissions that operators are not obliged to determine are calculated in the emission database on the basis of reported activity data and emission factors. Emission factors for stationary combustion sources are differentiated according to the kind of furnace and thermal output, where the fuel consumption is the activity data. For other sources, the emission factor depends on the type of technological process, kind and amount of product and means of reducing emissions.

The PM10 and PM2.5 emissions are determined on the basis of the percentage amounts of the given PM fraction in the overall SPM emissions. If the source is fitted with equipment for reducing SPM emissions, the amounts of the PM fractions depend on the separation principle of this equipment. For combustion sources without separators, the amounts of the individual fractions are determined according to the kind of fuel; for other sources, the means of formation of SPM is decisive (Hnilicová 2012).

Emissions from the collectively monitored sources in the Czech Republic

Collectively monitored sources recorded in REZZO 3 include emissions from local household heating, fugitive SPM emissions from construction and agricultural activities, ammonia emissions from livestock farming and applications of mineral nitrogenous fertilisers, VOC emissions from extensively used organic solvents and SPM and VOC emissions from coal mines and landfills.

With the exception of household heating, emissions from collectively monitored sources are calculated only from data monitored by national statistics and any inter-annual changes are generally connected with trends in the relevant statistical indices. In contrast, inter-annual changes in the amounts of emissions from local household heating are dependent primarily on the character of the heating season, which is expressed in the emission model in the number of degree-days (Chap. III.), and changes in the composition of combustion facilities. The results of the Census of persons, houses and apartments (SLDB) is the main basis for calculation of emissions from local household heating. Estimates of fuel consumption in the 1990–1999 period were preformed according to the 1997 methodology (Machálek, Machart 1997) and, for the 2000–2016 period using the 2007 methodology (Machálek, Machart 2007).

Data from mobile sources are also monitored collectively (REZZO 4) and include emissions from road, rail, water and air transport and off-road machinery and mechanisms (agricultural, forest and construction machinery, military vehicles, etc.). Emissions from abrasion of tyres, brake linings and roads calculated from traffic levels are also part (CDV) has drawn up the balance of emissions from mobile sources since 1996 on the basis of information on sales of automotive fuels according to ČAPPO (Czech Association of Petroleum Industry and Trade) (since 2000 on the basis of CSO data) and its own set of emission factors (Dufek et al. 2006). The Agricultural Technology Research Institute (VÚZT) processes emissions from mobile sources. A consistent set of emission values from transport has been available since 2000; updating of emissions for the 1990–1999 period is problematic because of the lack of input data on automotive fuel sales.

Recalculation of emissions

The emission inventory calculated according to the requirements of the CLRTAP convention as of 15 February 2017 contains updating of heavy metal and POP emissions for the 2000–2015 period. Inventories of emissions of these pollutants from combustion processes and selected technological processes were performed according to the national emission factors, which were obtained by evaluating the results of individual emission measurements at sources in the Czech Republic (Modlík 2017). Heavy metal emissions from abrasion of tyres, brakes and roadways were added for the monitored period. The PAH emission inventory for mobile sources was newly drawn up on the basis of the emission factors published in the EMEP/EEA air pollutant emission inventory guidebook-2016 (EEA 2016a). Consequently, the contribution of mobile sources to overall emissions of benzo[a]pyrene are lower than was formerly stated. Methodical modification of the emission inventory led to an improvement in the accuracy and consistency of the presented data.

Emission trends

The trends in air pollution levels are closely connected with economic and social-political conditions and with development of knowledge about the environment, permitting more complete and accurate emission inventories. Emissions from stationary sources in categories REZZO 1 and REZZO 2 in the 1990–2016 period decreased substantially as a result of introduction of an air quality control system, which employs a number of instruments at various levels (normative, economic, information, etc.). The impacts of these instruments were manifested to the greatest degree at the end of the nineteen nineties, i.e. at a time when the emission limits introduced by the then-new legislation came into general effect. A substantial reduction in the production of emissions from the most important sources led, amongst other things, to reduction of long-range transmission of air pollution. However, problems persist in the area of compliance with pollution limit levels and thus attention has concentrated in recent years on emissions in categories REZZO 3 and REZZO 4, for which effective regulation measures have not yet been introduced. Revision of the Göteborg Protocol and Directive of the European Parliament and Council (EU) 2016/2284 imposes on the Czech Republic the obligation to reduce the emissions by 2020 for PM2.5 by 17%, SO2 by 45%, NOx by 35%, VOC by 18% and NH3 by 7% and by 2030 for PM2.5 by 60%, SO2 by 66%, NOx by 64%, VOC by 50% and NH3 by 22% compared to 2005.

Emission trend in the period 1990–2001

In 1991, Act No. 309/1991 Coll., on protection of the air, came into force, supplemented by Act No. 389/1991 Coll., on state administration in air protection and fees for pollution thereof, which introduced emission limits with validity from 1998 for the first time in the history of the Czech Republic. The time delay was intended to enable preparation of sources for the new operating conditions. The national economy was restructured, sources were modernised and a great many of them were closed or reduced operations. These changes were manifested, e.g. in the iron and steel production sector, where there was a substantial reduction in production after 1990 (Fig. II.3). For example, termination of the production of pig iron at Vítkovické železárny in 1998 contributed to improvement of the air quality directly in the centre of the city of Ostrava. Since 1991, the energy production sector has witnessed shutting down or modernisation of old furnaces and/or the installation of new low-emission fluidised-bed furnaces. Sulphurremoval facilities were installed in coal-burning power plants in 1996–1998. Solid and liquid fossil fuels used for combustion sources with lower thermal output (heating plants, boiler rooms) were gradually replaced by natural gas The number of pollutants subject to fees was extended and rates were increased for their discharge. These measures led to a reduction in the emissions of all the pollutants in categories REZZO 1 and REZZO 2.

Emissions from local household heating decreased most in the 1993–1997 period as a result of conversion to gas heating in municipalities and state support for heating with electricity. The consumption of fossil fuels in 2001 was 60% lower compared with 1990 (Fig. II.4).

Compared with 1990, in 2001, country-wide emissions were lower for SPM by 87%, SO2 by 88%, NOx by 68%, CO by 38%, VOC by 45% and NH3 by 37% (Fig. II.1).

Emissions trend in the period 2002–2012

Legislation that reflected a number of European Directives came into effect in 2002. Act No. 86/2002 Coll., on protection of the air, was adopted and, together with Act No. 76/2002 Coll., on integrated pollution prevention and control, created the basic framework for dealing with the issue of air pollution. The Czech Republic undertook to meet the national emission ceilings for emissions of SSO2, NOx, VOC and NH3 according to Directive 2001/81/EC with validity as of 2010. A substantial decrease occurred in emissions from sources in the REZZO 1 category as a result of fulfilling the National programme to reduce emissions from existing very large combustion sources (Government Regulation No. 372/2007 Coll), which introduced emission ceilings for SPM, SO2 and NOx stipulated for individual LCP sources4 from 2008. Cut-backs in a number of production sectors after 2007, caused by the economic crisis, were manifested in a reduction in industrial emissions (Fig. II.2). Further measures to reduce emissions were introduced in the iron and steel sector. The most important of them was related to the installation of bag filters on the existing electrostatic separators at Aglomerace 1 operations in Třinecké železárny, a.s., in 2008 and Aglomerace Sever operations at ArcelorMittal Ostrava a.s. in 2011.

The favourable trend in reducing consumption of fossil fuels in the local household heating sector did not continue after 2001, mainly because of the increasing prices of natural gas and electricity. In the 2002–2007 period, the consumption of coal decreased and was replaced by increasingly popular heating with wood. These changes led to a reduction in SPM and SO2 emissions. In 2009–2012, as a result of the Green Light for Savings programme, buildings were insulated and environmentally unsound heating was replaced by low-emission sources.

Compared with 2001, in 2012 country-wide emissions were lower for SPM by 35%, SO2 by 31%, NOx by 36%, CO by 29%, VOC by 39% and NH3 by 22% (Fig. II.1).

Emission trend in the 2013–2016 period

The Air Protection Act came into force in 2012, introducing stricter emission limits for combustion sources pursuant to Directive 2010/75/EU on industrial emissions. The validity of some new emission limits is progressive, so that the operators of sources are able to prepare for their fulfilment. In connection with issuing of the BAT5 conclusions, changes are being made in the integrated permits for industrial sources, especially in the areas of stipulating and fulfilling emission limits. The most important technical measures to reduce emissions in the 2013–2016 period included installation of sulphur-removal and nitrogen-removal equipment for combustion products (e.g. Elektrárna Třebovice power plant, Teplárna Karviná heating plant and Teplárna České Budějovice, a. s. heating plant) and installation of bag filters on the existing electrostatic separators at Aglomerace 2 operations of Třinecké železárny, a.s. in 2015 and at Aglomerace Jih operations of ArcelorMittal Ostrava a.s. in 2016.

The Air Protection Act concentrated on reducing emissions from the local household heating sector and introduction of minimum emission parameter values for combustion sources with overall rated thermal input of up to 300 kW as they came on the market between 2014 and 2018. From 2022, it will be possible to operate only boilers complying with emission class 3 in this group of sources, which should lead to removal of old types of boilers and their replacement by more modern equipment with lower emissions. Replacement of boilers is taking place gradually and, together with reducing the energy demands of buildings, these measures are supported by the state subsidy policy.

The inter-annual trend in pollutant emissions in 2016 confirms the anticipated impacts of the changes in the legislation in 2012, especially in the area of important combustion sources, which are contributing to a gradual decrease in emissions of SO2 (by 16%) and NOx (by 8%). A slight increase in degree-days in the cold heating season of 2016 led to an increase in some emissions from household heating and in the tertiary sector.

Tab. II.1 The classification of air pollution sources according to the method of emission monitoring

Tab. II.2 The comparison of emissions of main pollutants, 2015–2016 (preliminary data)


Fig. II.1 The development of total emissions, 1990–2015

Fig. II.2 The output of basic industrial products, 1990–2015

Fig. II.3 Fuel Consumption in REZZO 3 sources, 1990–2016

1 Methodologies and results of emissions inventories.
2 Emissions in NFR structure.
3 SPE control mechanism.
4LCP – Large Combustion Plants – combustion plants with nominal heat consumption of 50 MW and greater.
5BAT – best available techniques