The periodically published Tabular Survey is a result of the processing of air quality data that is systematically stored over the calendar year in the air quality database from all significant networks monitoring air pollution in the country. From the table Air pollution monitoring sites based on the owner and location in the administrative region of the Czech Republic - 2000 it is apparent from how many monitoring (active) stations of the overall number of the stations data were stored and processed.

Since 1992, the current information technology was utilized to prepare the Air Quality Information System (ISKO) and the restructured former Imission Information System (IIS) became an integral component, along with other information programs for evaluating air quality.

The Air Quality Information System collects and generally provides access to data gathered within significant air pollution monitoring networks. It thus allows more effective general utilization of this expensive data. The integrated regionalised evaluation of air pollution levels, and analysis of the development over time of the status of air pollution in this country would not be feasible without collecting and archiving systematically at one place all the air pollution data available. The continuous need to make this assessment objective also necessitates simultaneous accessibility of emission, meteorological and climatic data and geographic information on the locations of pollution sources, the extent and location of forest growth, residential areas, roadways and similar information.

Fig. 1 schematically depicts ISKO´s links to data sources and co-operating systems. The scheme outlines the interconnection of air quality monitoring networks and sources of data on emissions with data processing and information layers represented by ISKO, and the linkage to a higher-level layer - cross-sectional information systems. The actual interconnection is carried out through exchange of data on magnetic media, over switched data lines and, in case of data from the AIM network, also over fixed circuits of the CHMI´s private data network.

Computer System

Since 1993, both the Tabular Survey and the Graphic Yearbook have been completely prepared on an innovated computer system. It consists of a computer network around an SUN ENTERPRISE 450 database server with the installed Ingres multi-user relative database system under the Solaris operating system. The data core of the information system is implemented under RDBMS Ingres with predominant utilization of client-server architecture. The concept of the system is based on distributed processing in the local network at Sun SPARC working stations and personal computers with direct access of processing and analytical programs, such as the ARC/INFO geographical information system on Sun ULTRA, the statistical programs SPSS, Systat, tabular and graphical programs Excel and Harvard Graphics, etc., to the data in the central database on SUN ENTERPRISE 450 with features of uninterrupted and backed-up operation.

The Czech Hydrometeorological Institute has its regional offices in all the former regional capitals, which are mainly concerned with measurements, data collection and initial processing within their respective regions. The offices are connected to the central system in Prague via CHMI´s private data network. This Institute´s organizational structure and current technical facilities, as well as a growing need to ensure that the regional offices and cooperating organizations can manage a matching scope of data processing and utilization for their areas, indicate the need for a gradual transition to some form of a more thoroughly allocated concept of the entire Air Quality Information System.

Air pollution assesment

Assessment of the status of the air pollution is based on air pollution limit values as specified in the Decree of the Federal Committee for the Environment of October 1, 1991, attached to Act No. 309/1991 Coll., the Clean Air Act in wording of Act No. 211/94 Coll. (This Table has been copied over from the above Decree, with some formal modifications).

Limit values for the Czech Republic
Pollutant Expressed as Limit values [µg.m-3]
IHr IHd IH8h IHk General requirement**
Suspended particulate matter SPM 60 150   500 IHd and IHk must not be exceeded in more than 5% of measurements annually.
Sulphur dioxide SO2 60 150   500
Sulphur dioxide and suspended particulate matter SO2 + SPM   250*      
Nitrogen oxides NO2 80 100   200 IHd and IHk must not be exceeded in more than 5% of measurements annually.
Carbon monoxide CO 5000 10 000
Ozone O3  160  
Lead in suspended particulate matter Pb0.5    
Cadmium in suspended particulate matter Cd 0.01    

Legends
*
Calculated as the arithmetic sum of average daily concentrations of the two components
**
i.e. the 95th percentiles of daily concentrations must not exceed IHd and the 95th percentiles of the half-hour concentrations must not exceed IHk
IHr
average annual pollutant concentration. Average concentration is understood to be the mean value of concentration, determined at a given site over a time period of one year as the arithmetic mean of average 24-hour concentrations
IHd
average daily pollutant concentration. Average concentration is understood to be the mean value of concentration, determined at a given site over a time period of 24 hours. Average daily concentration is also understood to be the mean value of at least twelve evenly distributed measurements of average half-hour concentrations over a time period of 24 hours (arithmetic mean)
IH8h
 average eight-hour pollutant concentration. Average eight-hour concentration is understood to be the mean value of concentration, as determined at a given site over a time period of eight hours
IHk
average half-hour pollutant concentration. Average half-hour concentration is understood to be the mean value of concentration as determined at a given site over a time period of 30 minutes



Currently, a new Clean Air Act is under preparation along with its implementing regulations. New legislation reflecting the requirements of the European Union will come into force in 2002. The following tables show the limit values and margins of tolerance set by the newly prepared Decree of the Ministry of the Environment of the Czech Republic on air pollution limit values. These values are used for the assessment of pollutants in the ambient air for the year 2000 and their exceedences are shown in the Yearbook's supplement.

The prepared limit values for the protection of health, vegetation and ecosystems pursuant to the draft Decree of the Ministry of the Environment of the Czech Republic setting the air pollution limit values, conditions and requirements for air quality assessment, evaluation and management and implementation of air protection regulation measures, and setting the accessible level of odor nuisance and the way of its detection and the volume of and access to information on air quality.

Limit values for health protection
Pollutant Averaging Interval Limit value Margin of tolerance 1)
(for the year 2000) 		Maximum tolerated
number of exceedences
per calendar years
SO2
 calendar year
50 μg·m-3
without margin
of tolerance
0
24 hours
125 μg·m-3
without margin
of tolerance
3
1 hour
350 μg·m-3
150 μg·m-3
24
NO2
 calendar year
40 μg·m-3
20 μg·m-3
0
1 hour
200 μg·m-3
100 μg·m-3
24
PM10
 calendar year
40 μg·m-3
8 μg·m-3
0
24 hours
50 μg·m-3
25 μg·m-3
35
CO
 max. daily
8h moving
average
10 000 μg·m-3
6 000 μg·m-3
0
Benzen
 calendar year
5 μg·m-3
5 μg·m-3
0
O3
 max. daily
8h moving
average
120 μg·m-3
without margin
of tolerance
25,
3-year average
Pb
 calendar year
0.5 μg·m-3
0.5 μg·m-3
 
Cd
 calendar year
0.005 μg·m-3
0
0

Legends
1 The margin of tolerance is the per cent of air pollution limit or a part of its absolute value, by which the limit value may be exceeded. This value is reduced regularly in subsequent years until it reaches zero value.


Limit values for the protection of ecosystems
Pollutant Averaging Interval Limit value Margin of tolerance 1)
(for the year 2000) 		Maximum tolerated
number of exceedences
per calendar years
SO2
 calendar year
and witnter
period (1.10.-31.3.)
20 μg·m-3
without margin
of tolerance
0
NOx
 calendar year
30 μg·m-3
without margin
of tolerance
0
O3
 AOT402) calculated from
1h values between May
and July, 5-year average
18 000 μg·m-3
without margin
of tolerance
0

Legenda
1 The margin of tolerance is the per cent of air pollution limit or a part of its absolute value, by which the limit value may be exceeded. This value is reduced regularly in subsequent years until it reaches zero value.
2 AOT40 is the sum of differences between hourly concentrations higher than the threshold concentration 80 μg·m-3 and the value 80 μg·m-3, in the period from 8 a.m. to 8 p.m. CET.