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 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. What is positive is that in the course of nine 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 regulations and analyses carried out both prior to the actual start and during the routine operation of the Monitoring System and was last optimised in the “Amendment to the monitoring subsystem projects of 1998”. 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. 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 in 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 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; 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 (QA) in analytical laboratories taking part in the Monitoring System has been included in the activities of the laboratories as well as their supervising organizations (Public Health Service – analytical laboratories providing data to the Monitoring System databases have currently been part of the public health institutes, private laboratories and other institutions). 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 and keeping regulatory diagrams and 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. Most collaborating laboratories of the Public Health Service use accredited methods. Evaluation of their suitability for use within the monitoring is also part of the audit. As in previous years, the QA analyses included sampling reliability, good sampling practice and data submission.

In advance of the regulations concerning accreditation (CSN EN ISO/ICE 17 025), the QA/QC work-group now requires Standard Operational Procedure (SOP) for collection, storage and transport of samples and for presenting results from the Monitoring Central as supplements to the Control Handbook.

Subsystem III has got its own QA/QC system. As for the newly implemented subsystems, Subsystem VII (Health effects and risks related to the occupational environment) has got its own mechanism of QA analyses. Data for Subsystem VIII (Health risks related to contamination of urban soil) are submitted by the laboratories supervised by the QA/QC working group since participating in other subsystems.

Tabe 3.1 Participants of the Environmental Health Monitoring System in the Czech Republic

City

Implementation
in subsystem:

Living
conditions

Environment
quality

Code IISE

Number
of inhabitants

1

2

3

4

5

61)

8

Basic participants:

Benešov

x

x

 

x

x

x

 

A

3

BN

16 262

Brno

x

x

x

x

 

x

 

C

3

BM

373 272

České Budějovice

x

x

x

x

 

x

 

B

4

CB

96 742

Děčín

x

x

x

 

 

x

 

C

5

DC

52 333

Havlíčkův Brod

x

x

x

 

 

x

 

A

2

HB

24 327

Hodonín

x

x

 

 

 

 

 

A

4

HO

27 085

Hradec Králové

x

x

x

x

 

x

x

C

3

HK

96 408

Jablonec n/N

x

x

x

x

 

x

 

B

4

JN

45 031

Jihlava

x

x

x

 

 

x

 

A

3

JI

50 377

Jindřichův Hradec

 

x

 

 

 

x

 

A

1

JH

22 728

Karviná

x

x

 

 

 

x

 

C

5

KI

64 653

Kladno

x

x

x

 

 

x

 

D

4

KL

70 702

Klatovy

x

x

 

 

 

x

x

B

2

KT

22 988

Kolín

x

x

x

 

 

x

 

C

5

KO

30 095

Kroměříž

x

x

 

 

 

x

x

B

3

KM

29 228

Liberec

x

x

x

 

 

x

 

C

3

LB

98 380

Mělník

x

x

 

 

 

x

 

C

4

ME

19 219

Most

x

x

 

 

 

x

 

D

5

MO

68 090

Olomouc

x

x

x

 

 

x

 

A

3

OL

102 246

Ostrava

x

x

x

x

 

 

 

D

5

OS

315 442

Plzeň

x

x

x

x

x

x

 

D

4

PM

164 336

Prague

x

x

x

x

 

x2)

 

C

5

A

1 160 118

Příbram

x

x

x

 

 

x

 

B

4

PB

35 710

Sokolov

x

x

 

 

 

 

 

D

4

SO

24 968

Svitavy

x

x

 

 

 

x

 

B

2

SY

17 583

Šumperk

x

x

 

x

 

x

 

A

2

SU

29 318

Ústí n/L

x

x

x

x

x

x

 

D

5

UL

94 871

Ústí n/O

x

x

x

 

 

x

 

B

2

UO

15 074

Znojmo

 

x

x

x

 

x

 

B

2

ZN

35 691

Žďár n/S

x

x

x

x

x

x

 

A

2

ZR

24 171

Associated participants:

Frýdek-Místek

x

 

 

 

 

 

 

C

4

FM

61 018

Litoměřice

 

x

 

 

 

 

 

C

4

LT

24 762

Pardubice

 

x

 

 

 

 

 

C

4

PU

90 171

Remarks:
1) periodically since 1994, in 2002 – A10, BN, JH, JN, SU
2) Prague 10
Subsystem 7 is nationwide.
IISE – Integrated information system of environment.
Codes A1–A10 are used for individual districts of Prague.
Definition of living conditions and quality of environment, see Chapter 12.
Number of citizens is actualised at 1. 1. 2002 (Statistical Yearbook of the CZ, ČSÚ 2002).

Fig. 3.1 Environmental Health Monitoring System in the Czech Republic – participant cities


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