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Acid Deposition Case Studies


Background Information

Since 1st January 1993, the Czech Republic has become a separate state along with Slovakia, both states being previously known as Czechoslovakia.

Key Facts on the Czech Republic

10.3 million (Dec 1999)

78 866km²

Prague (1.2m population)

Germany, Austria, Slovakia, Poland

Four seasons, coldest January (-2C), warmest July (20C)

Average altitude:
450m above sea level

Air Quality:
Generally poor, particularly during winter months

Acid Deposition:
One of the highest acid deposition levels in Europe

Czech Republic, 2001

Source: The Perry-Castañeda Library Map Collection, The General Libraries, The University of Texas at Austin, Austin, TX 78713-8916, USA

Acidic Pollutant Emissions

The main acidic pollutants are sulphur dioxide and oxides of nitrogen and during 1998, the Czech Republic emitted 0.44 million tonnes of sulphur dioxide and 0.41 million tonnes of nitrogen oxides. This is a sizeable output considering the relatively small population of 10.3 million, although sulphur dioxide emissions have fallen by 76% since 1990. Emissions of nitrogen oxides have also been falling in the Czech Republic, by nearly half between 1990 and 1998. Nevertheless, air quality in Czech Republic is still considered to be a problem.

The Czech Republic is an important industrial nation in Europe with its main economic sector being industry, employing more than 2 million and generating 62% of national income. There are several heavily polluted areas within the Czech Republic, such that a large percentage of the population live in severely polluted air. In Prague, winter concentrations of sulphur dioxide and particulates are often more than twice the World Health Organisation (WHO) Air Quality Guidelines (AQG). At these times the long term guidelines set by WHO for exposure to these pollutants are exceeded.

The most polluted area of the Czech Republic is in northern Bohemia which stretches for 60km from Chutomov to Literomice (see map). Here, power stations are fuelled by lignite, otherwise known as brown coal, which has a high sulphur content and when burnt produces large quantities of sulphur dioxide. Additionally, because the coal has a low calorific value, large quantities are required to obtain the power. The low energy value of the coal also means that it has to be burnt near the mines. Hence the industrial areas are situated in the valley of the Ore Mountains where mining takes up almost 10 000 hectares of land.

The towns in the valleys of northern Bohemia are further troubled by temperature inversions which trap the pollutants in the cold air of the valley bottom. This prevents normal air currents from dispersing the pollutants. The towns become enveloped in a cold and smelly smog, whereas up on the hill tops the air is warm and clear. The valley is thus known as the Bohemian basin.

Acidic Pollutant Depositions

The Czech Republic also receives acidic pollutants from other countries, as shown in Table 3.1.

Table 3.1: Originating countries of sulphur deposition on Czech Republic


Sulphur Deposition, 000 tonnes 1998 (weight of sulphur)

Czech Republic
















Total sulphur deposition


Total deposition of sulphur on the Czech Republic during 1998 was around 0.14 million tonnes (by weight of sulphur). When this is compared to the amount that is emitted in the Czech Republic (0.44 million tonnes of sulphur dioxide or 0.22 million tonnes of sulphur, 1998) it becomes apparent that much of the sulphur produced within the Republic is transported to other countries. Most of this pollution is exported to Poland, Germany, and the Russian Federation, as shown in Table 3.2.

Table 3.2. Selected countries receiving sulphur from the Czech Republic (1998)

Country receiving sulphur pollution
from Czech Republic

Sulphur deposition, '000 tonnes,
originating from Czech Republic
(weight of sulphur)





Russian Federation








The Czech Republic, along with other countries in the industrialised zone from Poland through to Germany, the Benelux countries to the UK, receive the highest levels of acid deposition in Europe. In the Czech Republic industrial sources of sulphur and nitrogen oxides account for the major emission sources, whilst in the UK for example vehicles are a more important source of nitrogen oxides due to much higher car ownership.

Effects of Acid Deposition on Forests

Around one third of the Czech Republic is covered in forest and so timber is a major economic resource. The high levels of acid deposition experienced over recent decades have had serious damaging effects on both broadleaf and coniferous trees in the Czech Republic. The European Forest Damage Survey results for 2000 show that 52% of all trees in the Czech Republic are classified as moderately to severely damaged (trees with more than 25% loss of leaves or needles). The trees most affected are Norway spruce (Picea abies) in the mountainous area of the country where soil acidification and acidic deposition have resulted in the loss of 100,000 hectares of forest.

Trees aged over sixty years are particularly vulnerable and all trees on the forested areas of the Ore mountains and other land over 800m altitude have been affected by sulphur dioxide. The trees are additionally stressed on occasion with extreme climatic conditions.

The problem of acidification was first observed by foresters in the 1960s and 1970s when individual spruces died and crown thinning of older trees became apparent. The damage is now spreading to the valleys and is also affecting deciduous trees. More resistant species of spruce such as Picea pungens are being planted where trees have died and other areas are being replaced by grassy meadows.

Effects of Acid Deposition on Water

Water supplies in many parts of the Czech Republic are already severely polluted as a result of poor sewage treatment, industrial effluent and artificial fertilisers. The severe soil acidification problems often lead to higher pH levels in groundwaters in the Czech Republic.

Surface water acidification can be expected when acid deposition levels are high and the bedrock is sensitive to acid deposition (i.e. there is little buffering capacity). Lakes and rivers in the mountainous Erzgebirge forested areas have been identified as acidic as a result of high acid deposition levels and sandy soils with low buffering capacity.

Effects of Acid Deposition on Buildings

Many of the buildings in the Czech Republic have become blackened by air pollutants and corrosion is occurring at faster rates than through normal weathering. In the capital city of Prague, there are more than 200 large emission sources in addition to small sources and motor vehicles which contribute around 56 000 tonnes of sulphur dioxide, 24 000 tonnes of nitrogen oxides and 24 000 tonnes of particulates to the city air each year. The highest concentrations of pollutants are recorded in the historical core of the city in the 'Old Town' due to a combination of factors including topography and emission source locations. This air pollution causes high economic losses through accelerated corrosion on buildings in Prague and other buildings in the Czech Republic.

Effects of Acid Deposition on Health

The human health effects from air pollution and acidification are evident in the Czech Republic. Since the 1960s, air pollution has become an increasing problem affecting health. During smog conditions, hospital admissions increase, most relating to respiratory diseases. Those most at risk are the young, the elderly and asthmatics.

Life expectancy and infant mortality appear to be affected in areas associated with high levels of air pollutants. In northern Bohemia high levels of air pollutants are associated with high numbers of bronchial diseases. During February 1993, winter smog conditions occurred in northern Bohemia and daily mean concentrations of 825µgm-3 sulphur dioxide and 480µgm-3 particulates were recorded. These levels exceed World Health Organisation AQGs by around 4 times indicating the severity of the air quality in this region.

Control and Policy

The Czech Republic are committed to reducing sulphur emissions through the 1994 UNECE Protocol 'Further Reduction of Sulphur Emissions'. This Protocol requires the Czech Republic to reduce sulphur emissions by 50% by the year 2000, 60% by 2005 and 72% by 2010 (all based on 1980 levels). To date, the country is on target to achieve this level of emissions reduction.

The Government has also introduced counter measures to reduce air pollution during smog conditions. These include limiting car use and the use of high quality coal in power stations at such times.