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 data could be obtained from a lower number of localities (e.g. dietary exposure and biological monitoring), as well as for economic reasons.

Data on the implementation of different monitoring subsystems and on the quality of the living conditions and of the environment in different localities together with demographic data are summarized in Fig. 3.1 and Tab. 3.1 (Atlas of the Environment and Population Health in the Czech and Slovak Federal Republics, 1992). A positive result is that in the course of five years of routine operation no changes in the number of participants under monitoring have occurred. This means that the whole system can be considered to be stabilized and regular from the point of view of the scope of the monitoring activities.

3.2 Monitored factors and their limits

A set of factors (pollutants, contaminants, analytes and indicators) has been monitored in the individual subsystems. Their listing follows from the respective standards and results of the preliminary analyses completed. These factors, pollutants and contaminants and the subsystems intended for monitoring are listed in the Supplement. In addition, the critical parameters or limit values, if established, are given.

For the evaluation of results in the subsystems, several types of limits have been applied. On the one hand, they are limits given in our standards and public notices, and on the other hand, they are values adopted from presentations of international institutions (e.g. the World Health Organization) which do not always have to have normative validity in our country. In question are namely exposure limits of the acceptable daily intake type, or recommended daily intake in the evaluation of exposure to contaminants or trace elements from foodstuffs or drinking water, or tolerable internal doses in evaluating the content of toxic substances in biological material. In the course of the existence of the Monitoring System a natural development in the formulation of these critical quantities is taking place, just as in the determination of their numerical values, and therefore their changes are reflected in the Special Reports and in the Summary Report.

3.3 Information system of the Monitoring System and processing of results

The structure of databases and sets of corresponding computer codes ensures the collection of results at the end users of the information system (measuring laboratories), their transport to the directors of the individual subsystems, and their independent processing according to the requirements of the users of the Monitoring System. The directors archive all original data in special databases to enable their reprocessing according to other criteria. The databases are designed as standard products allowing data processing to the usual extent. They 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 (arithmetic and geometric mean, standard deviation) or the nonparametric ones (median, quantile). Most data on pollutant concentrations in an environment showing a statistical distribution close to the lognormal one are processed in this way. Both the detection limit of the analytical method used and the extreme values due to a specific high burden in 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 appropriately. Therefore it seems more appropriate and more objective to use the nonparametric sample characteristics (median, quantile), thus avoiding any wrong assumptions as for the statistical distribution of the processed data. It should be noted that the calculation of individual statistical characteristics is limited by the number of values in the sample processed. In cases of their small numbers the mean value (mean and median resp.) is presented only.

Nevertheless, the application of the nonparametric characteristics has not yet been generalized. The reason is that some standard or reference data are still presented as arithmetic mean, thus giving overestimated values. In the monitoring data databases, the characteristics of all types are available and one of the goals is to achieve a progressive transition to a nonparametric way of expressing the results.

In many cases, in a series of values obtained on the concentration of a contaminant (analyte) in some medium (the environment or biological material) there is a greater number of results below the detection limit (so called “negative results” or “trace amounts”). It is difficult to evaluate such a situation quantitatively. As far as a measured concentration being below the detection limit, for the calculation of sample characteristics a value equaling one-half of the detection limit is used. Often, there also occurs a situation in which in a series of values measured there is a greater number of results falling below respective detection limits. Further processing of such data can be loaded with an error which, from the point of view of the value of exposure, is not substantial because, in principle, it is presented at the bottom of the exposure limit range. In the cases where the number of negative measuring exceeds 50% of the total number of analyses, such trace amounts are usually described verbally only and a quantitative evaluation of the results is not always performed.

Results presented in previous Summary Reports were accompanied by information on previous years. In the present Summary Report, for greater clarity, previous data are summarized under the term “Range 1994/8” giving the maximum and minimum concentration or exposure values registered in the years 1994 through 1998 in charts for each specific contaminant. Along with current characteristics (e.g. median and 90% quantile) for the year 1998 one can get an idea of the exposure of the population to individual contaminants during the whole period of routine operation of the Monitoring System.

For this year’s Summary Report there was carried out for the first time an evaluation of the trends of factors under follow-up in each of the environmental components studied in the mentioned period of 1994 through 1998. The evaluation was materialized through the correlation coefficient for an isolated assessment of data series, e.g. on the development of the concentration of a certain contaminant over time, or by analysis of variance in more complicated situations. Evaluations are usually carried out at the 5% level of significance (p < 0.05) when not indicated otherwise. In retrospective, graphic illustrations, a positive or negative trend (a statistically significant rise or fall in values over time) is indicated by a symbol (“+” or “-”) above or below the range of evaluated data. Situations when the hypothesis of random distribution of the values is not ruled out, no symbol is given.

3.4 QA/QC system

Quality assurance (QA) and quality control (QC) are ensured by independent measuring laboratories or organizations to which they belong. Independent activities in this field of interest are conducted by the directors of each subsystems. Detailed information is presented in the Technical Reports of each subsystem. A significant component of assurance of the quality of analyses is the participation of laboratories in comparative interlaboratory tests, application of reference materials and appropriate keeping of documentation.

Adequate ensuring of QA/QC programs by measuring laboratories is controlled by an independent working group that conducts independent assessments. Assessment of the quality of analyses in the laboratories and the credibility and accuracy of presented results that follow are anonymous in principle and conclusions of such check-ups are not published routinely. They are accessible only to the laboratory itself and the ordering authority. The objective of the procedures applied in the control activities is to direct the laboratories towards results that can be easily studied and checked up on.

Activities of the working group in 1998 were aimed at the amending of the Manuals for Controls of QA of Analyses, BIOLMON (further as MC only) and on active collaboration with laboratories in upping the standards of their work.

Collaborating measuring laboratories gradually update the MC according to changing conditions in their work from the technical as well as organizational points of view. Currently, about 30% of the laboratories are updating, on a regular on-going basis (usually with a frequency of one year), otherwise updates are carried out on an appeal or notice before an announced audit. This activity should be rated positively because it is a relatively considerable and mostly administrative burden for the laboratories. Nevertheless, in question is an important and beneficial task that is necessary to follow regularly.

The laboratories are also gradually preparing Standard Operation Procedures (SOP) for sampling and for the transfer of results for the further processing. The objective of such SOP (which may, in a way, be simple) is to standardize the mechanisms of checking up on the flawless transfer of final results from the laboratory after completing the analyses. The working group sees to the elaboration of these special SOPs for handing over results.

In Subsystem 2, “Drinking Water”, 80% of the laboratories have handed in these SOPs. In Subsystem 5, “Biological Monitoring”, designed for the selection of subjects for follow-up and for the taking, transporting, distribution and transfer of biological material, a single SOP (the so-called Protocol) was elaborated, which is generally valid for the whole subsystem. This type of SOP shall contribute in principle to better communication between responsible workplaces and thereby for the checking and elimination of potential errors in the results. Subsystem 4, “Dietary Exposure” is directed from one workplace and from the beginning has its own system of collecting samples and preparation for their analysis. In both audits that have taken place, this procedure was found to be adequate.

The participation of laboratories in programs of external control (so-called interlaboratory comparison of tests) has improved. In Subsystem 1, “Air”, 100% of the laboratories are participating in the external control program. Professionally controlled in this way is the analysis of samples taken at manual units concerning levels of sulphur dioxide, sum of nitrogen oxides, and polycyclic aromatic hydrocarbons. The laboratories are at least 90% successful. The function of automatic units is checked on and stabilized by the Calibration Laboratory at the NIPH. Of course, even that workplace should be under the supervision of an appropriate accreditation authority. Documentation is being prepared for a Manual for checking up on QA of analyses for monitoring the indoor air. In Subsystem 2, “Drinking Water”, 100% of the laboratories are participating in the program of external control, at least 80% of them were successful in 55 indicators under follow-up (there has yet to be check for some indicators). In Subsystem 5, “Biological Monitoring”, external control of laboratories collaborating in the analysis of elements is ensured by a system of ring samples, for the microscopic evaluation of chromosomal aberrations within the framework of the project through the aid of the reference laboratory. Laboratories conducting analyses on a commercial basis as well as certain laboratories of the Public Health Service have been accredited by the Czech Institute for Accreditation (ČIA). The workplace of Subsystem 4 has been accredited for methods which it applies in its activities within the framework of the Monitoring System. Several laboratories have received a certificate of accreditation from the ČIA. In summary, it may be stated that there still remain findings that need on-going attention and financial means:

As significant progress can be considered the fact that there are already laboratories that routinely work with SOP for taking and transport of samples, and for handing over of results for further processing and that there are ready conditions for the stabilization of results of routine monitoring of the indoor environment.

Tab. 3.1 Participants of the System of monitoring the environmental impact on population health

City

Implementation
in subsystem:

Living
condition
areas

Environ-
ment
cities

Code
IISŽP

Number of inhabi-
tants in [1000]

city/
/district
[%]

1

2

3

4

5

district

city

Basic participants:

Benešov

x

x

 

x

x

A

3

BN

88.7

15.9

17.9

Brno

x

x

x

x

 

C

3

BM

386.9

385.9

99.7

České Budějovice

x

x

x

x

 

B

4

CB

177.9

99.5

55.9

Děčín

x

x

x

   

C

5

DC

133.6

53.3

39.9

Havlíčkův Brod

x

x

x

   

A

2

HB

95.8

24.7

25.8

Hodonín

x

x

     

A

4

HO

161.7

28.1

17.4

Hradec Králové

x

x

x

x

 

C

3

HK

161.6

99.8

61.8

Jablonec n/N

x

x

x

x

 

B

4

JN

88.6

46.1

52.0

Jihlava

x

x

x

   

A

3

JI

109.1

52.4

48.0

Jindřichův Hradec

 

x

     

A

1

JH

93.9

23.0

24.5

Karviná

x

x

     

C

5

KI

284.7

66.4

23.3

Kladno

x

x

x

   

D

4

KL

150.1

71.7

47.8

Klatovy

x

x

     

B

2

KT

88.6

23.2

26.2

Kolín

x

x

x

   

C

5

KO

95.7

31.1

32.5

Kroměříž

x

x

     

B

3

KM

108.8

29.9

27.5

Liberec

x

x

x

   

C

3

LB

159.5

100.0

62.7

Mělník

x

x

     

C

4

ME

94.9

19.6

20.7

Most

x

x

     

D

5

MO

119.8

70.6

58.9

Olomouc

x

x

x

   

A

3

OL

225.9

103.8

45.9

Ostrava

x

x

x

x

 

D

5

OS

323.2

323.2

100.0

Plzeň

x

x

x

x

x

D

4

PM

169.4

169.4

100.0

Praha

x

x

x

x

 

C

5

AB

1 200.5

1 200.5

100.0

Příbram

x

x

x

   

B

4

PB

107.6

37.0

34.4

Sokolov

x

x

     

D

4

SO

94.9

25.9

27.3

Svitavy

x

x

     

B

2

SY

102.5

17.4

17.0

Šumperk

x

x

 

x

 

A

2

SU

127.3

30.2

23.7

Ústí n/L

x

x

x

x

x

D

5

UL

118.7

96.9

81.6

Ústí n/O

x

x

x

   

B

2

UO

139.1

15.3

11.0

Znojmo

 

x

x

x

 

B

2

ZN

114.2

36.2

31.7

Žďár n/S

x

x

x

x

x

A

2

ZR

125.8

24.5

19.5

Associated participants:

Frýdek-Místek

x

       

C

4

FM

228.7

62.5

27.3

Litoměřice

 

x

     

C

4

LT

114.1

25.8

22.6

Pardubice

 

x

     

C

4

PU

162.4

93.0

57.3

Uherské Hradiště

 

x

     

A

3

UH

145.6

27.5

18.9

Remark:

IISŽP - Integrated information system of environment.
City/district - quotient of inhabitants living in the city and in the district.
Codes AB1 - AB10 (A1 - A10 from tech. reasons respectively) are used for individual districts of Prague.
Evaluation of quality of living conditions and quality of environment, see Chapter 11.
Number of citizens is actualized at 1. 1. 1998 (Statistical Environmental Yearbook of the CR 1998).


Fig. 3.1 System of monitoring the environmental impact on population health - Participants


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