3. ORGANIZATION OF THE MONITORING SYSTEM |
3.1 Scope of the Monitoring System
The Monitoring System has been implemented in 30 localities including the capital Prague, selected district cities and the former regional capitals. Not all subsystems of the Monitoring System have been in operation in all cities since, in some cases, representative information can be obtained from a lower number of localities (e.g. for the subsystems of dietary exposure and biological monitoring), which also leads to cost savings. On the other hand, other subsystems require additional involvement of collaborating participants.
The data on the implementation of different monitoring subsystems, quality of living conditions and the environment and demographic statistics for all participating localities are summarized in Fig. 3.1 and Table 3.1 (Atlas of the Environment and Population Health in the Czech and Slovak Federal Republic, 1992). What is positive is that in the course of eight 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, as regards 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 standards and analyses carried out prior to the actual start of the Monitoring System and was last optimised in the “Amendment to the monitoring subsystem projects in 1999”. These factors together with the respective subsystems used for their monitoring are listed in the Supplement. In addition, the critical parameters or limit values, if established, are given.
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. 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 toxic substances content in biological material. By a temporal development, these critical quantities and their numerical values are being adjusted and the resulting changes are reflected in the Special 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 does not 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. 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 their small number, only the mean value (arithmetic mean or median) is presented.
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.
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”). Consequently, the quantitative assessment is difficult. 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 more safe 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. In 2001, prevalence rates of allergic diseases in children were compared for 2001 and 1996, trends in PAH concentrations in air were analyzed for the five-year period 1997–2001 and trends in PCB concentrations in human milk were studied for the interval 1994–2001.
3.4 QA/QC system
Quality assurance (QA) and quality control (QA) in analytical laboratories taking part in the Monitoring System has been included in the activities of the laboratories individually as well as their supervising organizations (Public Health Institutes, private laboratories). Information on QA/QC activities of the directors of different subsystems is presented in the Special Reports. Quality assurance in the laboratories of the Monitoring System is based on the interlaboratory comparison of sample analyses (circular sample analyses), use of reference materials for internal controls, regulatory diagrams and appropriate keeping of documentation records.
The QA/QC program is supervised by an independent working group, which carries out audits. Conclusions of these audits are not commonly published and are intended for use by participating laboratories to improve their work. The working group proceeds the way to induce the laboratory staffs to obtain controllable results. If accredited methods are used by a laboratory prior to the audit, their suitability for use within the monitoring is analysed.
To audit the QA in the laboratories, the working group uses the Manual for Control of QA laboratory audits that gives guidance to the laboratory staff in creating conditions for their activities to be transparent, providing high quality results and tracing the samples processed in the past to make them available e.g. for possible arbitration procedures.
In anticipation of accreditation standards (CSN EN ISO/ICE 17025), the QA/QC working group started requiring the standard operation procedures (SOPs) for sampling, sample storage and transportation and submission of the obtained results to the Monitoring System Headquarters to be available as an annex to the Manual for Controls of QA laboratory audits. Most laboratories have already been able to present SOPs for sampling and data submission as part of their Manuals for Control of QA laboratory audits. The subsystem “Noise” has got its own QA/QC system and thus its own approach to the selection of the measurement sites and data handling.
By December 31, 2001, 38 laboratories took part in the Monitoring System (except Subsystem III) and 28 out of them were holders of the accreditation certificate of the Czech Accreditation Institute (several laboratories within one public health institute may be accreditation certificate holders).
Most Public Health Service laboratories that are not accreditation certificate holders or carry out analyses beyond the accreditation scope are holders of inter-laboratory comparison certificates (circular sample analyses).
The collaborating laboratories for the newly implemented Subsystem VIII (Health risks from municipal soil contamination) and laboratories involved in the Subsystem I project “Indoor Air Quality” succeeded in the audit of the Working Group for Control of QA of Analyses.
Table 3.1 Participants of the Environmental Health Monitoring System in the Czech Republic
City |
Implementation |
Living |
Environment |
Code IISE |
Number |
|||||
1 |
2 |
3 |
4 |
5 |
6 |
|||||
Basic participants: |
||||||||||
Benešov |
x |
x |
|
x |
x |
|
A |
3 |
BN |
16 154 |
Brno |
x |
x |
x |
x |
|
x |
C |
3 |
BM |
381 862 |
České Budějovice |
x |
x |
x |
x |
|
x |
B |
4 |
CB |
98 186 |
Děčín |
x |
x |
x |
|
|
x |
C |
5 |
DC |
52 758 |
Havlíčkův Brod |
x |
x |
x |
|
|
x |
A |
2 |
HB |
24 626 |
Hodonín |
x |
x |
|
|
|
|
A |
4 |
HO |
27 720 |
Hradec Králové |
x |
x |
x |
x |
|
x |
C |
3 |
HK |
98 080 |
Jablonec n/N |
x |
x |
x |
x |
|
|
B |
4 |
JN |
45 428 |
Jihlava |
x |
x |
x |
|
|
x |
A |
3 |
JI |
51 408 |
Jindřichův Hradec |
|
x |
|
|
|
|
A |
1 |
JH |
22 986 |
Karviná |
x |
x |
|
|
|
x |
C |
5 |
KI |
65 019 |
Kladno |
x |
x |
x |
|
|
x |
D |
4 |
KL |
71 572 |
Klatovy |
x |
x |
|
|
|
x |
B |
2 |
KT |
23 100 |
Kolín |
x |
x |
x |
|
|
x |
C |
5 |
KO |
30 382 |
Kroměříž |
x |
x |
|
|
|
x |
B |
3 |
KM |
29 995 |
Liberec |
x |
x |
x |
|
|
x |
C |
3 |
LB |
99 155 |
Mělník |
x |
x |
|
|
|
x |
C |
4 |
ME |
19 514 |
Most |
x |
x |
|
|
|
x |
D |
5 |
MO |
69 588 |
Olomouc |
x |
x |
x |
|
|
x |
A |
3 |
OL |
102 702 |
Ostrava |
x |
x |
x |
x |
|
|
D |
5 |
OS |
320 041 |
Plzeň |
x |
x |
x |
x |
x |
x |
D |
4 |
PM |
166 759 |
Prague |
x |
x |
x |
x |
|
|
C |
5 |
AB |
1 181 126 |
Příbram |
x |
x |
x |
|
|
x |
B |
4 |
PB |
36 636 |
Sokolov |
x |
x |
|
|
|
|
D |
4 |
SO |
25 565 |
Svitavy |
x |
x |
|
|
|
x |
B |
2 |
SY |
17 255 |
Šumperk |
x |
x |
|
x |
|
A |
2 |
SU |
29 632 |
|
Ústí n/L |
x |
x |
x |
x |
x |
x |
D |
5 |
UL |
95 491 |
Ústí n/O |
x |
x |
x |
|
|
x |
B |
2 |
UO |
15 079 |
Znojmo |
|
x |
x |
x |
|
x |
B |
2 |
ZN |
35 778 |
Žďár n/S |
x |
x |
x |
x |
x |
x |
A |
2 |
ZR |
24 387 |
Associated participants: |
||||||||||
Frýdek-Místek |
x |
|
|
|
|
|
C |
4 |
FM |
61 322 |
Litoměřice |
|
x |
|
|
|
|
C |
4 |
LT |
25 417 |
Pardubice |
|
x |
|
|
|
|
C |
4 |
PU |
91 309 |
Remarks:
IISE – Integrated information system of environment.
Codes AB1–AB10 (A1–A10 from tech. reasons respectively) are used for individual districts of Prague.
Definition of living conditions and quality of environment, see Chapter 14.
Number of citizens is actualised at 1. 1. 2001 (Statistical Yearbook of the CZ, ČSÚ 2001)
New subsystems 7 and 8 are not in the routine operation yet, therefore
they are not involved in Table 3.1.
Fig. 3.1 Environmental Health Monitoring System in the Czech Republic – participant cities