3. ORGANIZATION OF THE MONITORING SYSTEM |
3.1 Scope of the Monitoring System
The Monitoring System has been implemented in 30 cities including the capital Prague, regional capitals and selected former district cities. Not all subsystems of the Monitoring System have been in operation in all cities for economical and technical reasons. On the other hand, other subsystems require additional involvement of collaborating participants.
The cities participating in each of the monitoring subsystems are shown in Fig. 3.1 and the data on the implementation of monitoring subsystems, quality of living conditions and the environment and population numbers are summarized in Tab. 3.1. What is positive is that in the course of ten years of routine operation of the Monitoring System, both the number and structure of its participants have remained unchanged, meaning that the system can be considered as stabilized and regular in terms of the scope of the monitoring activities.
3.2 Monitored factors and indicators and their limits
Various factors (pollutants, contaminants, analytes and indicators) have been monitored within the individual subsystems. Their list is based on the respective regulations and analyses carried out both prior to the actual start and during the routine operation of the Monitoring System. These factors together with the respective subsystems used for their monitoring are listed in the Supplement. In addition, respective limit or reference values, if established, are given for each of the factors.
For evaluation of the results, several types of limits have been applied. On the one hand, these are limits given in Czech standards and regulations, and, on the other hand, these are values taken from documents of supranational institutions (e.g. the World Health Organization and US Environmental Protection Agency), which usually do not have the force of standards in the Czech Republic. This is true namely of the exposure limits such as the acceptable daily intake (ADI) or recommended daily intake (RDA) applicable to contaminants or trace elements from foodstuffs or drinking water, or tolerable internal doses applicable to the toxic substances content of biological material. These limits and values are being adjusted to keep up to date with the latest developments and the changes are reflected in the Technical Reports and the Summary Report.
3.3 Information system and data processing
The structure of the databases and corresponding computer programs enable the collection of results from the information system end users (measuring laboratories), their transport to the directors of the individual subsystems, and independent processing according to the requirements of the Monitoring System users. The directors archive all original data in databases for possible reprocessing according to other criteria, if needed. The databases are designed as standard products allowing data processing to the usual extent, are compatible with other database systems and allow additional data processing and evaluation, if required.
The quantitative data processing is based on the calculation of the parametric sample characteristics (e.g. arithmetic mean) or the nonparametric ones (median, percentile). Most data on environmental pollutant concentrations show a statistical distribution close to the lognormal one. Both the detection limit of the analytical method used and the extreme values due to a specific burden of a locality or population (so called non-systematic fluctuations) are to be taken into account. If the burden does not show a normal distribution, an arithmetic mean of the values obtained cannot reflect the situation properly. Therefore, it seems more appropriate and more objective to use the nonparametric sample characteristics (median, percentile) thus avoiding possible unrealistic assumptions about the statistical distribution of the data processed. Nevertheless, general application of the nonparametric characteristics has not yet been possible. The reason is that some standard or reference data are still presented as arithmetic means, the use of which gives overestimated results. In the Monitoring System databases, characteristics of all types have been currently available.
It should be noted that the calculation of individual statistical characteristics is limited by the number of values in the sample processed. In case of small numbers, only their mean value (arithmetic mean or median) is presented. Some data on a contaminant (analyte) concentration in an environmental component or biological material may fall below the detection limit of the analytical methods used (so called “negative results” or “trace amounts”). If the concentration measured is below the detection limit, a value equalling one-half of the detection limit is used for the calculation of sample characteristics (based on the assumption of an even distribution of the values below the detection limit). This may lead to overestimated results; nevertheless, such an approach is safer than considering the values to be zero. Frequently, a greater number of the results can fall below the detection limit and their processing may be subject to error, which, from the point of view of exposure to the factor studied, is not substantial since this principally concerns exposure close to the lower allowable limit. If the number of the negative measurement results exceeds 50 %, such trace amounts are usually described only verbally and their quantitative assessment is not routinely performed.
The trends in environmental quality and population health are established for the given time intervals in each of the subsystems; their evaluation reflecting both linear and non-linear development of concentrations or population exposures to environmental contaminants is being regularly presented within each of the subsystems.
3.4 QA/QC system
Quality assurance (QA) and quality control (QC) in analytical laboratories taking part in the Monitoring System have been included in the activities of the laboratories as well as their supervising organizations. This means analytical laboratories as part of the public health institutes after reorganization of the Public Health Service, private laboratories and laboratories of other institutions.
The main parts of the QA system for analyses in the Monitoring System laboratories are the accreditation procedure steps focused on:
Information on QA/QC activities of the directors of different subsystems is presented in the Technical Reports.
Most collaborating laboratories of the Public Health Service use accredited methods according to CSN EN ISO/ICE 17025. As in previous years, the QA control for analyses included sampling reliability, observance of good sampling practice and adequate data submission. The Centre for Quality Control and Management in Health Care as part of the NIPH conducts laboratory accreditation audits.
Tab. 3.1 Participants of the Environmental Health Monitoring System in the Czech Republic
City |
Implementation in subsystem: |
City code |
Number of inhabitants |
||||||
1 |
2 |
3 |
4 |
5 |
6 |
8 |
|||
Basic participants: |
|||||||||
Benešov |
x |
x |
|
x |
x |
x |
|
BN |
16,277 |
Brno |
x |
x |
x |
x |
|
x |
|
BM |
370,505 |
České Budějovice |
x |
x |
x |
x |
|
x |
|
CB |
95,986 |
Děčín |
x |
x |
x |
|
|
x |
|
DC |
52,155 |
Havlíčkův Brod |
x |
x |
x |
|
|
x |
|
HB |
24,320 |
Hodonín |
x |
x |
|
|
|
|
|
HO |
26,575 |
Hradec Králové |
x |
x |
x |
x |
|
x |
x |
HK |
95,755 |
Jablonec nad Nisou |
x |
x |
x |
x |
|
x |
|
JN |
44,991 |
Jihlava |
x |
x |
x |
|
|
x |
|
JI |
50,174 |
Jindřichův Hradec |
|
x |
|
|
|
x |
|
JH |
22,795 |
Karviná |
x |
x |
|
|
|
x |
x |
KI |
64,146 |
Kladno |
x |
x |
x |
|
|
x |
|
KL |
70,328 |
Klatovy |
x |
x |
|
|
|
x |
x |
KT |
22,873 |
Kolín |
x |
x |
x |
|
|
x |
|
KO |
29,817 |
Kroměříž |
x |
x |
|
|
|
x |
x |
KM |
29,180 |
Liberec |
x |
x |
x |
|
|
x |
|
LB |
97,677 |
Mělník |
x |
x |
|
|
|
x |
|
ME |
19,077 |
Most |
x |
x |
|
|
|
x |
|
MO |
68,028 |
Olomouc |
x |
x |
x |
|
|
x |
x |
OL |
101,624 |
Ostrava |
x |
x |
x |
x |
|
|
|
OV |
314,102 |
Plzeň |
x |
x |
x |
x |
x |
x |
|
PM |
164,703 |
Prague |
x |
x |
x |
x |
|
x1) |
|
A |
1,161,938 |
Příbram |
x |
x |
x |
|
|
x |
|
PB |
35,508 |
Sokolov |
x |
x |
|
|
|
|
|
SO |
24,999 |
Svitavy |
x |
x |
|
|
|
x |
|
SY |
17,538 |
Šumperk |
x |
x |
|
x |
|
x |
|
SU |
29,073 |
Ústí nad Labem |
x |
x |
x |
x |
x |
x |
|
UL |
94,544 |
Ústí nad Orlicí |
x |
x |
x |
|
|
x |
|
UO |
15,082 |
Znojmo |
|
x |
x |
x |
|
x |
|
ZN |
35,552 |
Žďár nad Sázavou |
x |
x |
x |
x |
x |
x |
|
ZR |
24,028 |
Associated participants: |
|||||||||
Litoměřice |
|
x |
|
|
|
|
|
LT |
24,608 |
Pardubice |
|
x |
|
|
|
|
|
PU |
89,725 |
Remarks:
1) Prague 10
Codes A1–A10 are used for individual districts of Prague.
Number of inhabitants is actualized up to 1. 1. 2003
(Statistical Yearbook of the Czech Republic, Czech Statistical Office, 2004)
Subsystem 7 is implemented nationwide.
Fig. 3.1 | Environmental Health Monitoring System in the Czech Republic – participant cities |