Free air

      Free air is the element of the environment in which most important life processes of living organisms take place, among them processes of assimilation and respiration, and also processes of oxidation (combustion).
      The Earth's atmosphere is a mixture of gases of constant proportions: in its pure state air contains 78% nitrogen, 21% oxygen and the remaining 1% is carbon dioxide, argon, neon, helium, methane and krypton. Air also contains other compounds and substances which, if occurring in excessive quantities are called pollutants. Sources of air pollution can generally be divided into natural sources resulting from nature's activities (forest fires, volcano eruptions, soil erosion and others) and artificial (anthropogenic) ones resulting from the activities of man.
      Excessive quantities of substances and compounds contained in the air have harmful effects on other environmental elements like soil, water, vegetation, animals and also human health and life. Air pollution is one of the most dangerous threats to the environment. It is worth remembering, however, that harmfulness of pollution does not depend only on the concentration of the substance in the air, but also on its chemical and toxic qualities, state of aggregation and reaction time.

The main sources of air pollution in urban areas are:
• power stations and thermal power stations
• transport
• industry, manufacturing and processing
• residential heating
• burning of waste materials

Sources of air pollution in Cieszyn

      The quality of air in Cieszyn is influenced both by local emissions generated at concentrated points (industrial plants), scattered sources (numerous household boiler-rooms, ovens and furnaces), linear sources (transport) and also pollutants originating from industrial areas located in the distance of 25 to 60 kilometres from the city like Rybnik Coal Field (north of Cieszyn), Upper-Silesian Industrial District (in the north-east) and Karvina-Ostrava Industrial District (in the north-west). Also the Metallurgical Industrial Complex in Třinec should be counted as a concentrated point.
      Emission of pollutants is balanced on basis of annual reporting that plants specified as 'significantly burdensome to air cleanness' are obliged to carry out. In 2001 1 725 plants throughout the country, of which 341 are located in Silesian Voivodeship, were included in this kind of reporting. According to the data of Central Bureau of Statistics in 2001 about 32,800 tonnes of dust pollution (over 20% of the country's emission) and about 34,095 tonnes of gaseous pollution (about 30% of the country's emission excluding carbon dioxide) were released.

Quality of air in Cieszyn

      The magnitude of pollution measured in a given area depends mainly on local weather conditions and topographic profile. The significantly varied topographic profile of Cieszyn; characterised by; numerous river and creek valleys, hills, valley slopes results in the fact that different areas of Cieszyn have different microclimate conditions (e.g. air temperature, speed and direction of wind); which explains local differences in concentrations of individual air pollutants.
      In the Cieszyn area there are two points for the continuous monitoring of concentrations of air pollutants whose findings are used to analyse and define the quality of air.
      The Air Pollutant Monitoring Station at the Cieszyn Branch of Silesian University has been in operation since summer 1997. The setting up of the station and the purchase of the necessary equipment was subsidised from the town's budget (total sum of PLN 270,000 between 1995 and 1997). The measuring point was located on the roof of a hall of residence at ul. Niemcewicza. Since December 1996 the station has been carrying out fully automated measuring of basic air pollutants: particulate matter, sulphur dioxide, nitrogen oxides, tropospheric ozone and also basic meteorological parameters.
      The measurement of air pollutants in the city centre is carried out by the Silesian Medical Bacteriological Station: the measuring point has been located in Górny Rynek since 1995; purchase of measuring equipment for the point has also been subsidised from the town's budget (PLN 5,900 in 1998).