Ambient air pollution by suspended particles of fractions PM10 and PM2.5, benzo[a]pyrene and ground-level ozone is a major problem for air quality in the Czech Republic (Fig. 1). The pollution levels in a particular year depend on the amounts of emissions and the prevailing meteorological and dispersion conditions. Most air pollution characteristics have exhibited a decreasing trend since 2000, although this is less marked than in the 1990's. Nonetheless, the concentrations of these pollutants, which have serious consequences for human health, have exceeded the pollution limit values every year at a number of locations.

From the local to regional perspective, the most serious situation is still in the agglomeration of Ostrava/Karviná/Frýdek-Místek. Limit values are nevertheless exceeded in all zones and agglomerations; however, the pollution limit values are exceeded in all the zones and agglomerations. The high concentrations in the Ostrava/Karviná/Frýdek-Místek agglomeration are caused, not only by Czech sources, but also by transfer of emissions from Poland. Industrial production is very concentrated on both sides of the border, with a high density of built-up areas with local solid-fuel heating units and a well-developed transportation infrastructure (Chap. V.3). In Prague and Brno, the main problems are caused by pollutants derived mainly from traffic, affecting a substantial part of the population (Chapters V.1, V.2).

Deteriorated ambient air quality is not a problem only in agglomerations and larger cities, but also in small settlements, where local heating units make a considerable contribution to air pollution by suspended particulates and benzo[a]pyrene. It can be anticipated that above-limit concentrations may also occur in municipalities where these pollutants are not measured.

A substantial part of the Czech Republic is exposed every year to above-limit concentrations of tropospheric ozone However, because of the chemistry of ozone formation, these areas are not the most densely populated ones, like for suspended particulates PM10 and PM2.5 particles and benzo[a]pyrene. Consequently, the fraction of the population affected by abovelimit concentrations of ozone is substantially lower than the fraction affected by above-limit concentrations of PM10 and PM2.5 particles and benzo[a]pyrene.


In 2016, areas with deteriorated air quality (ozone excluded) covered approximately 25.9 % of the territory of the Czech Republic, inhabited by approximately 56 % of the population. In a great majority of cases, these areas were delimited because of exceeding the pollution limit values for suspended particulates PM10 and PM2.5, and also for benzo[a]pyrene. Exceeding of the pollution limit value for NO2 was responsible for designation of a smaller fraction of the territory to these areas in 2016. Areas with deteriorated air quality, excluding ozone, covered approx. 42.9% of the territory of the Czech Republic, inhabited by approx. 58.9% of the population (Chap. VII).

The daily limit value for PM10 suspended particles was exceeded over 1.4% of the territory of the Czech Republic, inhabited by approx. 7.3% of the population. The annual pollution limit value for PM10 was exceeded at only one measuring station. Compared to 2015, the fraction of locations where the daily pollution limit value was exceeded for PM10 decreased in 2016 and the territory with above-limit pollution levels for PM10 also decreased (Chap. IV.1).

The annual pollution limit value for suspended particulates PM2.5 was exceeded over 0.5% of the territory of the Czech Republic, inhabited by approx. 3% of the population. Compared to 2015, there was a substantial improvement in the conditions related to the annual average concentrations of PM2.5 and PM10 (Chap. IV.1).

Similar to previous years, the pollution limit value for benzo[a]pyrene was exceeded in a number of cities and municipalities (25.9% of the area of the Czech Republic inhabited by approx. 55.7% of the population). The estimate of the field of annual average concentrations of benzo[a]pyrene is accompanied by the greatest uncertainties of all the monitored substances, following from the inadequate density of measurements, especially at rural regional stations and in small settlements in the Czech Republic. From the viewpoint of pollution by benzo[a]pyrene, the air quality in small settlements is substantially affected by local heating units (Chap. IV.2).

The annual pollution limit value for nitrogen dioxide was exceeded at four locations with high traffic intensities (two stations each in Prague and Brno). However, it can be anticipated that the limit will also be exceeded at other stations with high traffic levels where measurements are not performed. Similar to previous years, the hourly pollution limit value was not exceeded for NO2 (Chap. IV.3).

The pollution limit value for tropospheric ozone was exceeded over 18.5% of the territory of the Czech Republic inhabited by approx. 3.5% of the population (average for 2014–2016; Chap. IV.4). The area of the affected territory was reduced by almost one third compared to the previous period (the average for 2013–2015) (Chap. IV.4).

The benzene pollution limit value was not exceeded at any location. The highest concentrations were attained, similarly to previous years, at stations in the Ostrava/Karviná/Frýdek-Místek agglomeration (Chap. IV.5).

The pollution limit values for arsenic and cadmium were not exceeded at any location in 2016 (Chap. IV.6).

Similar to previous years, the pollution limit values were not exceeded for lead, nickel, sulphur dioxide or carbon monoxide (Chap. IV.6, IV.7, IV.8).


The territory over which the pollution limit values were exceeded for tropospheric ozone (expressed as the AOT40 exposure index) was larger in 2016 than in 2015. Above-limit concentrations of O3 were recorded in 2016 especially in the Bílé Karpaty PLA, Pálava PLA and Podyjí NP (Chap. IV.4, Chap. VII.2).

The pollution limit values for sulphur dioxide and nitrogen oxides for protection of ecosystems and vegetation were not exceeded at any rural location where measurements were performed.

Based on the results of modelling (combined with measurements), the annual average SO2 concentrations exceeded the upper assessment threshold (UAT) over small areas in the Ústí nad Labem, Karlovy Vary and Moravian-Silesian regions. The average concentration in the winter of 2016/2017 exceeded UAT in the same regions and also in the Central Bohemian, Hradec Králové, Pardubice and Zlín regions (Chap. IV.7). Above-limit concentrations of NOx were also measured, especially around roadways; the results of model evaluation for the most valuable natural areas of the Czech Republic indicate that the pollution limit value for NOx was exceeded over only a very small area of several protected landscape areas in the Czech Republic (Chap. IV.3 and VII.2).


In 2016 5 smog situations were declared because of elevated PM10 concentrations. At least one smog situation was declared because of PM10 in 4 of the total of 16 SWRS areas. The greatest number of smog situations was declared in the territory of the Ostrava/Karviná/Frýdek-Místek agglomeration without the Třinec area. Compared to 2015, 4 fewer smog situations were declared and their overall duration decreased by 84%. The smog situations declared in 2016 were limited to only the areas of Central and Northern Moravia and the Plzeň area. No smog situation was declared in 2016 because of high tropospheric ozone concentrations (Chap. VI).


Inter-annual comparison of the production of emissions of the main pollutants in 2015 and 2016 indicates the substantial effect of the colder heating season in 2016 and thus the greater assumed consumption of fuel in households. Whereas for REZZO 1 sources, a decrease was recorded for most emissions compared to 2015 (with the exception of emissions of CO, VOC and NH3), the emissions from heating households exhibited an average increase of 3.7%, based on model calculations. The reduction in the production of emissions from REZZO 1 sources was greatly affected by the implementation of measures to reduce emissions from industrial and energy-production sources. Emissions from mobile sources in 2016 remained at the 2015 level.

The sector of local household heating continues to make a substantial contribution to air pollution, specifically to emissions of PM10 36.4%, PM2.5 54.5%, carbon monoxide 49.8%, arsenic 25.3% and benzo[a]pyrene 97.3%. The decisive contribution of the sector of public production of energy and heat predominated for emissions of sulphur dioxide 61.2% and nickel 39.3% and, in the sector of the production of iron and steel, emissions of cadmium, contributing 36.8%. The sectors of road freight transport over 3.5 t, passenger car transport and off-road vehicles and other machinery in agriculture and forestry produced 39.6% of emissions of nitrogen oxides and the abrasion of tyres and brakes in road transport contributed 35.1% of lead emissions. The most important sources of emissions of volatile organic compounds are in the sector of the use and application of organic solvents, which contributed 50.3% to pollution of the air by these substances.

The continuing reduction in emissions from sources mentioned in Annex No. 2 of the Air Protection Act is also reflected in the collection of fees for air pollution. The reported emissions subject to fees and fees paid decreased by approx. 16% for solid pollutants and SO2, while those for NOx decreased by 8%. The slight increase of 1.5% for VOC emissions could be connected with the overall increase in industrial production in the Czech Republic and surrounding countries.o pollution of the air by these substances.

As the emission data presented since 2013 are based on methodical procedures that were frequently substantially innovated (e.g. the composition of fuel and heating units for household heating, the freight vehicle fleet, addition of specific groups of sources over the entire time series), comparison of emissions cannot be related to data reported in previous yearbooks. However, it is important to note that the emission inventory for the entire period after 2000 is processed by consistent methodologies. Although minor changes and refinements will take place in coming years, the data presented since 2000 show an ongoing trend in reduction of the level of air pollution in almost all the sectors monitored according to the international classification of sources (Chap. II).


The year 2016 was below the long-term normal precipitation-wise. The average precipitation in the territory of the Czech Republic amounted to 635 mm, which is 94 % of the long-term normal for the period 1961–1990. The total precipitation was higher than in 2015 (531 mm).

Wet deposition of sulphur was slightly higher than in 2015. The highest values of wet deposition of sulphur were attained in the mountain areas (Moravian- Silesian Beskydy, Krkonoše).

Dry deposition of sulphur decreased compared to 2015. Total deposition of sulphur over the surface of the Czech Republic equalled 37,662 t. This represents a decrease, as the amount has varied around 50,000 t since 2007. The highest values were reached in the Krušné Mts. and in the Ostrava area.

Wet deposition of reduced forms of nitrogen (N/NH4+) increased in 2016 compared, while wet deposition of oxidised forms of nitrogen (N/NO3-) decreased. Total wet deposition of nitrogen on the surface of the Czech Republic equalled 44,418 t.

Dry deposition of oxidized forms of nitrogen decreased slightly.

Total deposition of nitrogen equalled 62,351 t of nitrogen on the surface of the Czech Republic.

Compared to 2015, wet deposition of hydrogen ions increased slightly to 411 tons in 2016. The increase in the wet deposition was probably caused by the larger total amount of precipitation compared to 2015.

Wet deposition of lead in 2016 was almost twice that in 2015, and thus returned to the level in 2013 and 2014. The highest values were attained in the territory of the Krušné Mts. and Moravian-Silesian Beskydy. Dry deposition of lead in 2016 was slightly higher than in 2015.

Wet and dry deposition of cadmium decreased in 2016. Similar to previous years, the highest values were attained in the Jablonec nad Nisou district.

Wet deposition of nickel ions decreased in 2016.

Wet deposition of chloride ions decreased compared to 2015 (Chap. IX).


Fig. 1 Areas with exceeding of the health protection limit values for selected groups of pollutants, 2016