V.2 AGGLOMERATION OF BRNO
The agglomeration of Brno is located in the centre of the
South Moravia region, it is identical with the administrative
territory of the city of Brno. As concerns ambient air quality,
Brno is one of three agglomerations and as such it is not
included in the South-eastern zone. The area of the
agglomeration is 230.22 km2 and the number of inhabitants is
The limit values for the protection of human health are exceeded in the long term in Brno, and namely for suspended particles PM10 and PM2.5, benzo[a]pyrene and in the parts of the agglomeration with heaviest traffic loads, also for NO2. The area of the agglomeration territory with the exceedance of the limit value for daily PM10 concentration may range from several per cent (2008) to almost whole territory of the agglomeration (2005) which depends mainly on meteorological conditions in the cold part of the year (see below). Similar variability exists as concerns the areas of the territory with the exceedance of the limit value for benzo[a]pyrene, however due to very small number of stations the highest uncertainty of defining may occur. As concerns average annual concentrations of PM10, not a single area with the exceedance of this limit value has been defined in the territory of the Brno agglomeration since the year 2008. The areas of the territory exceeding the limit value for the average annual concentration of NO2 are constant in the long term (in the order of several per cent) and are found near the most loaded transport routes (Table V.2.1).
The greatest share in the increased concentrations of the above pollutants is contributed primarily by traffic. Historically, Brno is the city located on the crossroad of communications. The important traffic communications intersect in the Brno territory at present as well (highways D1 and D2, expressways R52 to Vienna and R43 to Svitavy). Due to the still unfinished bypass from D1 in direction to Svitavy the already high number of cars in Brno is increased daily by transit traffic going through the city centre. Anyway the transit traffic is not fluent due to the unfinished Brno ring. All the above facts have their share in the increased emissions from traffic – particularly total suspended particles, nitrogen oxides, carbon moxide and volatile organic compounds. All the above pollutants have their majority source in emissions from traffic in the territory of Brno agglomeration, and they significantly contribute to the increased air pollution loads affecting the health of population. It is no accident that the limit values are exceeded in the pollutants with traffic as their majority source, and the highest concentrations are measured in the localities with heavy traffic loads.
V.2.1 Ambient air quality in the agglomeration of Brno
Suspended particles PM10 and PM2.5
In 2013 the limit value for the average annual PM10
concentration was not exceeded in any locality in the territory
of the agglomeration of Brno. The highest concentrations were,
as usual, measured in the localities with the highest traffic
loads, and namely Brno-střed and Brno-Svatoplukova; in the
previous years the limit value was exceeded several times (Fig.
V.2.1). In comparison with the year 2012 the average annual PM10
concentrations decreased in all urban localities, in the case of
the suburban stations Brno-Soběšice and Brno-Tuřany the levels
got worse in the order of several tenths. The worst air
pollution situation was confirmed at traffic stations where, in
average for the years 2006–2013, the concentrations were by 6.7
µg.m-3 higher than in the background localities (Fig. V.2.1). The situation at urban and suburban background stations is very
similar as at the regional rural background station
Mikulov-Sedlec in the years without long periods of unfavourable
dispersion conditions (2007–2009, 2012). On the contrary, in the
years when there occurred, mainly in the winter, the long-lasting
periods with the inversion character of the weather (January
2006, January 2010, February and November 2011), the effect of
the large accumulation of sources (household heating, traffic,
industry) and of stable atmosphere is apparent. It is manifested
by higher concentrations at urban background stations as against
the regional background station. In the long term (2005–2013)
the concentrations in urban and suburban background localities
are approx. by 4 µg.m-3 higher than in the regional background
In addition to dispersion conditions and the heating season there is another important factor, and namely wind erosion with regard to the agricultural character of the landscape in the whole South Moravia region. In this region wind erosion is a potential threat to over 50 % of agricultural land area, while 13 % of this area ranks in the category of most endangered soils. The worst situation is in the districts Břeclav, Hodonín and Znojmo, but also in the surroundings of Brno there are soils heavily endangered by wind erosion. Wind erosion occurs mainly in the periods when there is not the vegetation cover yet or when the vegetation cover is over (April, May and September, October). The soil erodibility is strengthened by longer episodes without precipitation and by wind velocity sufficient for transporting the soil particles. The influence of wind erosion is most apparent in the rural locality Kuchařovice where, in the long term, the measured PM10 concentration in April is the same as that in March (still within the heating season) and in October it is higher than in November and December (Skeřil et al. 2013; Fig. V.2.2). The long-term data from the background suburban station Brno-Tuřany showed that during the periods without precipitation (at least 5 days without precipitation) the average concentrations of PM10 are by 6.1 µg.m-3 higher than the long-term average for this period (Konozová, Skeřil 2011). As concerns PM2.5 particles measured in the agglomeration of Brno territory, the limit value is exceeded in the long term only in the localities with traffic loads (Fig. V.2.3); in background localities the limit value is exceeded or the levels are close to the limit value only in the years with longer episodes of unfavourable dispersion conditions (2006, 2010).
In 2013 the limit value for 24-hour PM10 concentration was exceeded only in traffic localities, however not in all of them. The localities Brno-Výstaviště, Brno-Kroftova and Brno-Úvoz (hot-spot) did not exceed the limit value. The background locality Brno-Tuřany did not exceed the limit value in the years without longer episodes of unfavourable dispersion conditions (2007–2009, 2012–2013). In comparison with the previous year 2012, similarly as in the case of average annual concentrations, both the concentrations and the number of days with concentrations higher than 50 µg.m-3 decreased in all types of localities (Fig. V.2.4). There is one exception, and namely the locality Brno-Svatoplukova with the heaviest traffic loads, where, in spite of the insufficient amount of data for the calculation of the annual average, the number of days with concentrations of PM10 > 50 µg.m-3 increased from 55 to 72 days. It can be concluded, that in spite of moderate improvement in other localities, and in some cases the improvement was even more marked (Brnostřed decrease from 66 to 48 days, Brno-Tuřany decrease from 29 to 20 days), in the locality near the Židenice military quarters the situation has got markedly worse. This is caused by very heavy traffic loads and partly also by local heating source (during inversions the plume from this source falls straight on the station, the neighbouring public transport stop and the road).
Traffic stations exceed the limit value in almost all cases within the whole monitored period and thus confirm the main problem as concerns the ambient air quality in the agglomeration of Brno – excessive traffic loads. The situation is documented very well by the graph in Fig. V.2.6, depicting the trend of hourly PM10 concentrations in the locality Brnostřed for the period 2005–2013. Heavy traffic during the morning rush hour is apparent very well, while the concentrations in the rush hour during the weekdays are much higher than during the weekends. The difference of concentrations between weekdays and weekends is apparent mainly between 5 a.m. and 8 p.m. – in the long term the difference is approx. 10 µg.m-3.
Generally, the concentration levels are highly dependent on meteorological/dispersion conditions during the winter season. The negative influence of unfavourable dispersion conditions in the winter period together with the heating season (residential heating) is reflected also in the distribution of days with PM10 concentrations higher than 50 µg.m-3; such days occur mainly in the cold part of the year. In this regard, in 2013 the months of January and February were absolutely dominant, and as concerns the end of the year, the number of exceedances was much lower thanks to the warm winter 2013/2014 with above-the-average temperatures (Fig. V.2.5). In other months the exceedance of the concentration 50 µg.m-3 is rather exceptional, occurring at traffic stations only. The highest number of exceedances of PM10 concentration for the calendar year 2013 was recorded in the traffic locality Brno-Svatoplukova (72 days), the lowest number in the suburban background locality Brno-Soběšice (12 days).
The development of concentrations since 1996 shows that there is almost no difference between the agglomeration of Brno and the agglomeration of Prague or the North-western zone. As concerns average annual concentrations, the trends have almost identical course and very similar concentration levels, which signifies both the supra-regional influence of meteorological conditions and similar impact. The Moravia-Silesia region is the only exception due to the different type of load. The trend of the 36th highest 24-hour PM10 concentration and the trend of the average annual PM2.5 concentration have similar courses. In both cases concentrations in the agglomeration of Brno are higher than in the agglomeration of Prague, which can be caused first by generally higher background of concentrations of suspended particles in Moravia and also by higher share of traffic stations in Brno.
Nitrogen dioxide (NO2)
In the territory of the Brno agglomeration the limit value
for the average annual NO2 concentration is exceeded only in the
localities with the heaviest traffic loads. On the contrary, the
limit value for 1-hour concentration of NO2 is not exceeded. In
2013 the limit value was exceeded in the localities Brno-Úvoz (hot-spot)
and Brno-Svatoplukova similarly as in the previous year;
moreover, the concentrations increased approx. by 1 µg.m-3. All
the remaining localities recorded decreased concentrations in
comparison with the year 2012. The locality Brnostřed, which
exceeded the limit value regularly in the previous years
(2005–2011), did not exceed it in 2012 and 2013, however, the
measured concentrations were very close to the limit value (39.1
µg.m-3 and 38.9 µg.m-3 respectively). The long-term background
concentrations measured in the locality Brno-Tuřany reach the
levels around 20 µg.m-3 and in the recent years a downward trend
has been recorded; the average annual concentration in 2013
amounted to 17.4 µg.m-3 (Fig. V.2.7).
The trend of NO2 concentrations in the monitored period is relatively stable at all stations. Unlike the particles, the measured values are not so much influenced by meteorological conditions, only the intensity of traffic is significant. In this respect, however, nitrogen oxide (NO) is much more significant; nevertheless, no limit value is set for this pollutant. Graph in Fig. V.2.6 depicts the long-term situation (2005–2013) of hourly concentrations of NO in the locality Brno-střed. The trends correspond very well with the concentrations of PM10 particles in this locality. The difference between weekdays and weekends is more marked there. It can be stated that the high PM10, NO and NO2 concentrations in the locality Brno-střed are caused mainly by traffic. Similar situation can be expected in the locality Brno-Svatoplukova.
Although in selected localities in the agglomeration of Brno the limit value for the average annual NO2 concentration is exceeded, the total results for the agglomeration are very good; the average values are approximately the same as the average for the whole Czech Republic. The agglomeration of Brno has the best results in the long term in comparison with the remaining agglomerations. As concerns 1-hour concentrations, a significant increase was recorded in certain years (2006, 2010). These are the years with the marked deterioration of ambient air quality in the cold part of the year due to unfavourable dispersion conditions (2006) or due to the very long heating season (2010). Still, the concentrations measured in the agglomeration of Brno are again the lowest ones in the long term.
The polycyclic aromatic hydrocarbons (PAH) are represented in
legislation by benzo[a]pyrene – a carcinogenic substance formed
during the combustion of solid and liquid fuels. In the
territory of the Brno agglomeration PAH are measured in two
localities – in the city centre with traffic loads (Brno-Masná)
and in the background residential area (Brno-Líšeň). While the
traffic locality Brno-Masná exceeded the limit value every year
in the period 2008–2012, the concentrations in the locality
Brno-Líšeň have not been exceeded as yet. In 2013 the
concentration in the locality Brno-Masná dramatically decreased
to the level representing 70 % of the concentration measured in
the year 2012, the concentrations are even lower than in the
background locality Brno-Líšeň. With regard to significant
impact of traffic in the centre of Brno and concentration levels
of the previous years, the 2013 concentration is suspicious and
cannot be regarded as reliable (Fig. V.2.8). The daily data show
that especially in the first quarter of the year the
concentrations in the locality Brno-Masná reached from one half
to one third of the previous levels, in the warm part of the
year the concentrations were comparable, and in the last quarter
the concentrations measured in the locality Brno-Masná were
higher as those in the previous years. With regard to average
monthly concentrations the winter months are very important
again – while in summer the concentrations reach practically
zero values, in wither they move in the average even around 5 ng.m-3.
This is caused by meteorological conditions and also by higher
levels of the regional background. Residential heating is in
operation practically only during the heating season and, at the
same time, within the South Moravia region it ranks right after
traffic as concerns most important sources of particles to which
PAH are bound. The sector of residential heating increases
spatial background concentrations in the whole region during the
cold part of the year. In traffic localities even higher
concentrations are measured which is caused by traffic emissions.
The long-term development of concentrations in the agglomeration of Brno, similarly as in the agglomeration of Prague or in the North-western zone, shows the levels close to the limit value. Generally, with regard to the long-term development in Brno, the background localities record the levels below the limit value, in the city centre with traffic loads the levels slightly exceeding the limit value are recorded.
Ground-level ozone (O3)
The monitoring of ground-level ozone is carried out in two
localities in the agglomeration of Brno – background
concentrations are measured at the station Brno-Tuřany, and
ozone is also measured in the city centre influenced by traffic
loads at the station Brno-Zvonařka. Ozone is a highly reactive
molecule readily reacting with most substances in the air.
Therefore the highest concentrations of ground-level ozone are
measured in clean localities with low concentrations of other
pollutants. On the contrary, the most loaded (traffic)
localities measure the lowest concentrations of ground-level
ozone. Ozone reactivity is demonstrated also in the measured
concentrations in the territory of the Brno agglomeration. In
the year 2013 the level of 120 µg.m-3 was not exceeded at any
station. The 26th highest 8-hour running average measured in the
locality Brno-Zvonařka reached 102.5 µg.m-3, in the locality
Brno-Tuřany the 26th highest 8-hour running average reached
The long-term development of ground-level ozone concentrations is dependent on meteorological conditions, particularly in summer periods when maximum concentrations are reached, and the agglomeration of Brno is no exception. The urban localities reach lower concentrations than the rural localities, which is evident also in the two above mentioned localities. In spite of the fact that Brno-Tuřany is not a rural locality, the measured concentrations are higher than in the city centre near Zvonařka in the long term.
V.2.2 Emissions in the agglomeration of Brno
At present there are approx. 660 individually registered
plants – sources of ambient air pollution in the territory of
the agglomeration of Brno included in the REZZO 1 and REZZO 2
database. Only several dozens of them have their significant
contribution to total emissions, primarily thermal energy
sources, the incineration plant of communal waste and a small
part of plants of the formerly highly developed engineering
industry (mainly foundries). As concerns heating in households
and in the communal sector there prevail central sources of heat
energy (about 54 % of flats) and gas boiler stations and local
gas boilers (about 37 % of flats). Only in a small part of the
housing stock, primarily in the city outskirts, coal, wood and
coke are used for heating.
In the period from 2002 to 2012 the above mentioned significant sources reduced all monitored emissions. As concerns TSP emissions this decrease is connected with modernization, or with the closure of some technological branches of production, primarily foundries (e.g. Slévárna Zetor or Šmeral, a. s.). According to the current data of the summary operational records there is only one significant source of TSP emissions, and namely Eligo, a. s., specialized in the production of dried milk products, followed by foundries (primarily Královopolská foundry) where, in addition to the reported TSP emissions, we can expect also a certain share of hardly determinable fugitive emissions.
In SO2 emissions the most significant share (approx. 33 t.year-1) is contributed by the incineration plant of communal waste SAKO Brno, a. s. The marked decrease of emissions from heat supply sources results from the reduced combustion of high sulphur fuel oils and the subsequent transition to the only type of fuel, and namely the natural gas.
The decrease of NOx emissions was reached, besides the gradual modernization of heat supply sources, also by the shut down of the TEDOM unit in the company ERDING, a. s. Brno-gas boiler Kolejní, which produced more than 200 t.year-1.still in the year 2002.
As concerns ambient air quality, there is a major problem in
the agglomeration of Brno, and namely with traffic, or rather
with the presence of pollutants in the ambient air, caused in
the most part by traffic. With regard to the location of Brno as
the highway intersection including a high percentage of transit
traffic passing through the city centre, this problem will not
be probably solved in the near future. First, similarly as in
Prague, it will be necessary to invest in the construction of
bypasses (displacement of emissions out of the city centre and
their marked reduction as a result of smoother traffic flow) and
thereafter take further traffic and organizational measures
until the situation improves. The situation out of the city
centre is a little better, the exceedances of the limit values
in the background localities such as Brno-Líšeň, Brno-Soběšice
or Brno-Tuřany occur only in the years with longer periods with
unfavourable dispersion conditions.
The agglomeration of Brno does not meet the limit values as concerns suspended particles (both PM10 and PM2.5), NO2 and benzo[a]pyrene. All these pollutants are closely connected with traffic in the agglomeration of Brno.
Other pollutants listed in the legislation comply with the limit values. In case of sulphur dioxide (both daily and hourly limit values), carbon moxide, lead, arsenic, cadmium and nickel the concentrations even remain below the lower assessment threshold in the long term. Benzene concentrations reach the levels close above the lower assessment threshold.
Fig. V.2.1 Average annual PM10 concentrations in selected
localities and at individual types of stations, agglomeration of
Fig. V.2.2 Average monthly PM10 concentrations, Kuchařovice, 2005–2013
Fig. V.2.3 Average annual PM2.5 concentrations, agglomeration of Brno, 2004–2013
Fig. V.2.4 Number of exceedances of 24-hour PM10 limit value
in selected localities and 36th highest 24-hour concentration of
PM10 at individual types of stations, agglomeration of Brno,
Fig. V.2.5 Number of days with concentrations of PM10 > 50 μg.m-3
in individual months, incl. total number of exceedances,
agglomeration of Brno, 2013
Fig. V.2.6 10 Trend of hourly PM10 and NO concentrations in the
locality Brno-střed, division into weekdays and weekends,
averages for the years 2005–2013
Fig. V.2.7 Average annual NO2 concentrations in selected
localities and at individual types of stations, agglomeration of
Fig. V.2.8 Average annual benzo[a]pyrene concentrations,
agglomeration of Brno, 2006–2013
Fig. V.2.9 Field of the annual concentration of NO2, Brno
Fig. V.2.10 Field of the 36th highest 24-hour concentration of PM10, Brno agglomeration, 2013