11. HEALTH RISKS FROM SOIL POLLUTION IN URBAN AGGLOMERATIONS

11.1 Organization of monitoring activities

The subsystem consists of urban soil monitoring with the objective to assess the degree of health risk following from exposure to toxic substances through ingestion of soil and particulate matter from soil (dust). Up to and including the year 2003, the subsystem also included the assessment of exposure to microbial agents. In view of that the greatest probability of increased exposure to noxious substances from contaminated soil is in the child population of pre-school age, the project has been focused on kindergarten playgrounds.

In the year 2004 there have been carried out samplings of soil and assessments of its contaminants in 134 kindergartens in participant cities of Monitoring System, namely in the kindergartens of Ústí nad Labem, Plzeň, České Budějovice, Liberec, Jablonec nad Nisou, Šumperk as well as in the cities of Teplice, Strakonice, Rokycany, and Jeseník. Included were all kindergartens in the cadasters of the cities under follow-up. The methodology of soil sampling was the same as in previous years, namely to the depth of 10 cm from five sampling sites (points) most frequently occupied by the children in each kindergarten. Upon homogenizing the samples from the sampling sites there has been carried out an analysis of composite samples for selected contaminants. Each kindergarten was thus represented by one composite soil sample, a total of 134 samples of topsoil.

11.2 Factors under follow-up

In each sample of topsoil from kindergarten playgrounds there have been studied the following factors:

Samples of topsoil were taken and processed following Standard Operation Procedures elaborated within the framework of an accession study, namely for sampling, storage, and transport of soil, for analytical determinations of selected metals and polyaromatic hydrocarbons in soils. Samples of soil for chemical analyses were taken in the period of May through September 2004. Elemental analyses were performed by x-ray fluorescence (RTF), except for beryllium and mercury, which were assessed by atomic absorption spectrometry (AAS). Polyaromatic hydrocarbons were analyzed by high-pressure liquid chromatography (HPLC).

The concentrations found were compared with the draft of public health limits in the amendment to the Ministry of Health Decree No. 135/2004, in which there have been set public health requirements for bathing sites, saunas, and for hygiene limits of sand in sandpits. There has been made an estimate of exposure to the contaminants under follow-up through the unintentional ingestion of soil, and the degree of their significance has been evaluated.

11.3 Levels of topsoil contamination

11.3.1 Toxic metals and trace elements

Concentrations of the metals under follow-up in topsoil vacillated within a wider range of values. Results are presented in Tab. 11.1a and 11.1b, and reviewed in Fig. 11.1a and 11.1b in mg/kg dry matter; presented are basic statistical parameters of the occurrence of selected metals and metalloids in the topsoil of kindergartens under follow-up.

The highest mean concentration of arsenic in the soil of kindergartens was found in Teplice (33.6 mg/kg), somewhat lower being in Strakonice (see Tab. 11.1b). The mean values found in kindergartens in the other cities ranged below 20 mg/kg. The highest mean concentration of lead was found in Jablonec nad Nisou (90.3 mg/kg), being lower in Rokycany and Liberec. In the other cities under follow-up the mean value in kindergartens was around 50 mg/kg and less.

Most often the draft limits were exceeded in arsenic in which the vast majority of soil samples exceeded the limit; and in lead in which the limit value was exceeded in roughly one half of cases. The greatest number of kindergartens exceeded the limit for arsenic in Teplice, Strakonice, Rokycany, and Jablonec nad Nisou (that being 100 %). In Ústí nad Labem the recommended limit value of arsenic was exceeded in 84 % of kindergartens, in Plzeň and Liberec that was 80 %, in České Budějovice 24 % of kindergartens, and in the kindergartens of Jeseník and Šumperk that was 20 % of them. Exceeding the limit for lead was found most frequently in Jablonec nad Nisou (in all kindergartens), in Rokycany (in 80 % of kindergartens), and in Liberec (in 65 % of kindergartens). Supra-limit concentrations of beryllium were found in the greatest number of kindergartens of Šumperk and Jeseník. Concentrations of mercury exceeding the limit were found most often in the kindergartens of Jablonec nad Nisou, elsewhere only sporadically. Higher chromium content occurred sporadically. Supra-limit concentrations of vanadium were also found sporadically except in Ústí nad Labem and in Teplice where the recommended limit was exceeded in approximately one half of the kindergartens. From the results it follows that least often supra-limit metal concentration values in kindergarten topsoil were found in Šumperk where, except for beryllium and arsenic, there have not been found any supra-limit concentrations of metals, as compared with the recommended values. On the other hand, the greatest numbers of kindergartens exceeding the contaminant limit content were in Ústí nad Labem and in Teplice.

11.3.2 Polyaromatic hydrocarbons

Results of determinations of polyaromatic hydrocarbons in topsoil samples from kindergartens are presented in Tab. 11.2a and 11.2b that include the basic statistical parameters for polyaromatic hydrocarbons classified by US EPA as being carcinogenic.

The concentrations of benzo[a]pyrene in surface water samples from kindergartens ranged between values below the detection limit up to the maximum value of 2 mg/kg found in a kindergarten in Jablonec nad Nisou. In Jablonec there has also been found the highest mean value for benzo[a]pyrene (0.62 mg/kg). On the other hand, the lowest content of this polyaromatic hydrocarbon was found surprisingly in the soil of kindergartens in Plzeň. The recommended maximum content of benzo[a]pyrene 0.1 mg/kg has been exceeded in the majority of kindergartens (Fig. 11.2).

In view of the lower health risk posed by benzo[a]anthracene and its higher recommended limit concentration in comparison to benzo[a]pyrene, the situation concerning contamination with this PAH representative, looks relatively favorable. The recommended content in uncontaminated soils, according to the amendment of Decree No. 135/2004, has been exceeded in only three kindergartens in České Budějovice and in Strakonice, in two kindergartens in Jablonec nad Nisou, and in one in Liberec and in Teplice. Thus, in Plzeň and in Rokycany the recommended limit of 1 mg/kg for benzo[a]anthracene was not exceeded by the values found in any of the kindergartens.

The content of chrysene found in the soil of kindergartens looks unfavorable in view of the draft limit that has been set very low. In as the draft value is below the detection limit of the analytical method used, it is difficult to express exactly the number of kindergartens meeting that value. In comparison with the draft limit of the most studied and healthwise most serious PAH, benzo[a]pyrene, the question arises whether the limit value for chrysene should not be revised.

11.4 The health risk of unintentional ingestion of soil

The concentrations of selected PAHs found in the soil of kindergartens within the framework of Subsystem VIII served as documentation for the evaluation of the health risk posed by contaminated soil through its unintentional ingestion by the child population of pre-school age. For an estimation of each indicator there have been used the median and maximum values found for metals and PAHs in the soil of kindergartens in each city.

The seriousness in relation to health, of the contamination of soil with metals can be expressed as the potential share in the overall oral exposure through unintentional ingestions of soil and particulate matter (dust) from soil, i.e. by the contribution to dietary exposure. The relation between the estimated exposure and the exposure limit (recommended by the WHO – PTWI, PMTDI, TDI, etc.) or reference dose RfD (set by US EPA) expresses also the so-called Hazard Index (HI), when the exceeding of the value “1” signifies a higher intake of a given substance than is acceptable. For the calculation of HI, for all metals there has been applied the reference RfD value (except for lead for which the RfD has not been set). In the estimate of potential exposure there have been applied exposure factors elaborated by US EPA (1998): unintentional ingestion of soil and particulate matter from soil – 200 mg per day, 210 days a year for a child of 15 kg mean body weight, the contemplated duration of exposure being 6 years.

For the calculation of a theoretical increase in the probability of contracting cancer due to exposure to a contaminant through unintentional ingestion of soil, there has been applied the method of health risk assessment or the linear non-threshold model of the relation between dose and effect following US EPA methodology. Calculations have been carried out for arsenic for which there are available guidelines, carcinogenic oral slope factor; and for polyaromatic hydrocarbons classified as carcinogenic by US EPA. As an acceptable level of theoretical risk of contracting cancer there has been considered 1*10-6, i.e. one additional case per 1 million of the population.

11.4.1 Exposure assessment – metals

In no kindergarten in any of the cities under follow-up has there exceeded the estimated intake of metals through soil ingestion the daily acceptable or tolerable intake recommended by the WHO. The highest tapping of the WHO daily exposure limit was found in all the cities in lead, only in Teplice and Strakonice the proportion of tapping the exposure limit in lead and of that in arsenic were almost equal. The tolerable weekly intake of lead by the organism (PTWI) is recommended by the WHO to be 25 µg/kg/wk. This exposure limit represents for a child of 15 kg mean body weight, a maximum tolerable intake of approximately 53.6 µg/day. The highest tapping share in the PTWI of lead through ingestion of soil and particulate matter from soil, was found in the kindergartens in Rokycany an Jablonec nad Nisou, and on the other hand, the lowest in Šumperk, Jeseník, as well as Ústí nad Labem. An estimate of the degree of tapping the exposure limit for lead in each of the cities is presented in Tab. 11.3a.

The tapping of the exposure limit for lead was followed by the PTWI of arsenic. For arsenic, i.e. for its inorganic (toxic) form, there has been recommended a maximum PTWI of 15 µg/kg per week (in children weighing 15 kg, that being about 32 µg/day). For the mean and maximum arsenic content in soil the share of intake was in the range of percentage units of the exposure limit, with the exception of Teplice where the intake of arsenic in PTWI from soil ingestion is higher (see Tab. 11.3a). For comparison, according to the monitoring data of subsystem IV, the average adult has an intake of toxic arsenic from foodstuff at the level of 4 % PTWI (27 % RfD), while along with PCBs, arsenic in the diet represents the greatest share in the carcinogenic risk from foodstuffs.

The estimated exposure in the other metals under monitoring was low. The tapping of the exposure limits recommended by the WHO was in the range of tenths of a percent.

A comparison of exposure with mostly considerably lower, i.e. more strict, exposure limits in the form of daily reference doses (RfD US EPA) has revealed that the intake from soil represents the greatest share in the overall reference dose for arsenic. The RfD of arsenic represents a considerably lower exposure limit than PTWI does, namely 0.3 µg/kg/day. From the point of view of assessing according to US EPA the share of arsenic intake through soil and dust ingestion in the overall daily reference dose is considerable in all the cities. The greatest intake has been estimated to be in Teplice where at the maximum value of arsenic concentrations in the soil the estimated intake of arsenic from soil exceeded the reference daily intake by 33 %. Data on the tapping of the exposure limit through soil ingestion for lead and arsenic are presented in Tab. 11.3a.

According to the magnitude of the estimated exposure in comparison with the reference value RfD with the aid of the Harm Index (HI), all the values for all the metals under surveillance in all of the cities were below the value of 1, around one third of the reference daily intake at the mean concentration of arsenic in the soil, and around one half in the case of the maximum concentrations found. An exception were Teplice and Strakonice where there have been found higher HI values; at the highest found arsenic content in the soil of a kindergarten in Teplice there has been found an HI exceeding the value of 1 (i.e. the estimated exposure exceeded the daily reference dose). As compared with the US EPA overall oral reference dose, there has been found a theoretically increased share in the intake of arsenic from soil in children in all the cities (Fig. 11.3).

11.4.2 Exposure assessment – polyaromatic hydrocarbons

In recent years there is an increasing frequency of studies on the relation between the ingestion of soil contaminated with organic substances (PAHs, PCB, PCDF, etc.) and the impact on the health of the child population. The ingestion of contaminated soil has been described in several studies as being one of the major pathways of exposure of small children to polyaromatic hydrocarbons (PAHs). Hitherto published studies on those problems point out the significance of the contamination of soil with carcinogenic PAHs and indicate the need to study the problem in more detail.

In the PAHs under follow-up that have been classified as non-carcinogenic, the fraction of the estimated intake through soil ingestion has been found in all the cities under follow-up to be overwhelmingly in hundredths, exceptionally tenths of a percent of the daily reference dose (RfD), the HI values ranging between 10-5 and 10-6, exceptionally in the order of 10-4.

11.4.3 Assessment of the carcinogenic risk

The estimate of the theoretical increase in the probability of the appearance of tumor diseases caused by exposure to arsenic in consequence of unintentional soil ingestion is in the majority of cities under follow-up in the order of 10-5, namely at the median and maximal concentrations of arsenic in kindergarten soil. The highest values have been found in Teplice, namely up to 5.14 additional cases per 100,000 of the population (5.14*10-5) at the maximum estimate, i.e. in the case of the kindergarten having the highest concentration of arsenic in its playground soil. For the median arsenic content in soil the estimate would be 3.36*10-5. On the other hand, the lowest risk of exposure to arsenic has been found in České Budějovice, 6.6*10-6, and in Jeseník and Šumperk where the additional risk in the order of 1*10-5 only in the case of the maximum local concentration in soil (see Tab. 11.3b).

The risk of contracting cancer due to exposure to polyaromatic hydrocarbons in consequence of unintentional soil ingestion is lower than that in the case of arsenic. Those values are in the range of 10-7 to 10-6. In carcinogenic PAHs the acceptable level of risk has been moderately exceeded in most cities as regards benzo[a]pyrene; and in the case of benzo[a,h]anthracene (Liberec, Plzeň, Rokycany), and benzo[b]fluoranthene (Jablonec nad Nisou). Values of the carcinogenic risk due to the intake of benzo[a]pyrene through the unintentional ingestion of soil in kindergartens of the cities under follow-up are presented in Tab. 11.3b.

Calculations of exposure and risk have been carried out following the standard US EPA procedure, nevertheless, the factors applied that determine exposure, are always biased by a certain degree of uncertainty that may in a given case lead to the overrating of the risk. Among the factors that could lead to overrating the risk is the varying measure of biological availability of the contemplated contaminants. The average daily potential dose is simultaneously considered as the dose absorbed (i.e. absorbed 100%) because the degree of biological availability of substances present in soil has not been studied in detail yet. In the estimation of the degree of carcinogenic risk and exposure to arsenic there joins in the fact that in soil there is being determined total arsenic, while exposure limits and guidelines on cancer risk are determined for the toxic form of arsenic, i.e. inorganic compounds. Organic compounds of arsenic are considered to be substantially less toxic or even not at all. Among the factors of uncertainty there are also the individual amounts of unintentionally ingested soil and particulate matter from the soil by children, as well as dermal exposure (absorption through the skin) described in several studies.

11.5 Partial conclusions

From the results it is apparent that arsenic and lead can be healthwise significant inorganic contaminants, the concentrations of which in most kindergartens of all the cities under follow-up exceeded the draft limits for uncontaminated soil. For those metals there has also been determined the theoretically maximum daily intake through unintentional soil ingestion by children. A relatively greater potential load with lead has been found in Rokycany, Jablonec nad Nisou, and Teplice. A greater arsenic burden has been found in Teplice, followed by Strakonice.

The health risk of exposure to PAHs not classifiable as carcinogenic by US EPA, has been found to be low. The recommended maximum content of benzo[a]pyrene in uncontaminated soil, that healthwise is considered to be the most significant carcinogenic polyaromatic hydrocarbon, has been exceeded in most of the kindergartens. The recommended benzo[a]anthracene content in soil has been exceeded only sporadically.

On the basis of a calculation of the theoretical increase in the probability of the appearance of tumor diseases in consequence of exposure to arsenic through unintentional soil ingestion there have been obtained values in the order of 10-5, i.e. higher than the acceptable level of risk, in all the cities under follow-up except for České Budějovice where there have been obtained borderline values. Also the degree of probability of an increase in tumor diseases due to exposure to carcinogenic PAHs was found to be borderline in all ten cities under assessment. Of the PAHs assessed, significant was namely benzo[a]pyrene, in several cases di-benzo[a,h]anthracene and benzo[b]fluoranthene.

Tab. 11.1a Concentration of elements in the kindergartens upper soil, cities of the Monitoring System

 

Concentration of element [mg/kg]

Lead

Chromium

Arsenic

Beryllium

Vanadium

Mercury

Copper

Recommended limits
for non-contaminated soil

50

85

10

1.5

80

0.3

45

Ústí nad Labem N = 19

Median

37.9

73.9

16.0

0.64

108.0

0.23

39.3

Arithmetic mean

38.7

81.3

16.4

0.63

109.3

0.25

41.4

Xmax

99.9

152.0

27.2

0.95

224.0

0.78

87.2

Xmin

18.5

34.1

7.9

0.36

37.5

0.06

16.5

Standard deviation

18.7

33.2

5.5

0.15

49.5

0.16

17.1

Standard deviation [%]

48.4

40.8

33.8

23.82

45.3

62.39

41.2

Šumperk N = 10

Median

30.3

47.4

9.0

2.04

46.8

0.08

17.6

Arithmetic mean

31.0

44.7

8.3

2.00

46.4

0.09

18.3

Xmax

44.9

60.2

10.9

2.48

63.4

0.21

28.2

Xmin

21.7

21.6

4.0

1.47

26.3

0.05

11.5

Standard deviation

7.5

9.8

2.0

0.31

10.8

0.04

4.8

Standard deviation [%]

24.2

21.9

24.0

15.73

23.3

45.38

26.6

Jablonec nad Nisou N = 10

Median

90.3

34.0

13.1

0.36

43.4

0.39

63.0

Arithmetic mean

97.7

35.3

13.9

0.46

45.7

0.40

72.3

Xmax

163.0

56.8

18.3

1.19

64.6

0.59

169.0

Xmin

53.0

27.7

11.0

0.05

30.0

0.19

18.5

Standard deviation

29.1

8.0

2.3

0.39

9.5

0.12

43.1

Standard deviation [%]

29.8

22.7

16.8

85.95

20.8

31.03

59.6

Liberec N = 20

Median

57.6

32.4

14.9

0.05

36.2

0.24

22.2

Arithmetic mean

58.8

35.3

17.5

0.09

39.2

2.45

27.3

Xmax

119.0

60.5

78.8

0.83

71.5

26.00

115.0

Xmin

29.8

17.8

8.0

0.05

13.0

0.11

9.8

Standard deviation

21.1

10.4

14.6

0.17

14.1

6.78

21.7

Standard deviation [%]

35.8

29.5

83.6

191.01

36.0

276.71

79.5

Plzeň N = 25

Median

46.3

44.8

17.2

1.48

65.7

0.19

30.5

Arithmetic mean

48.6

45.4

16.4

1.38

64.4

0.21

31.8

Xmax

88.2

82.7

28.0

2.24

117.0

0.43

64.3

Xmin

25.3

24.4

5.2

0.84

33.6

0.07

10.8

Standard deviation

15.6

13.0

6.4

0.35

18.0

0.09

12.5

Standard deviation [%]

32.1

28.6

38.8

25.45

27.9

42.26

39.3

České Budějovice N = 21

Median

40.6

39.2

6.1

8.00

36.2

0.16

17.7

Arithmetic mean

49.1

39.5

8.6

7.82

40.4

0.56

23.2

Xmax

97.9

64.3

27.3

9.63

73.0

7.20

60.3

Xmin

28.8

18.8

0.6

2.64

15.3

0.07

6.4

Standard deviation

19.4

10.7

6.4

1.21

14.3

1.50

15.6

Standard deviation [%]

39.5

27.1

74.8

15.46

35.3

266.87

67.5

N – number of kindergartens
Xmax – maximum pollutant concentration of monitored kindergartens
Xmin – minimum pollutant concentration of monitored kindergartens

Tab. 11.1b Concentration of elements in the kindergartens upper soil, associated cities

 

Concentration of element [mg/kg]

Lead

Chromium

Arsenic

Beryllium

Vanadium

Mercury

Copper

Recommended limits
for non-contaminated soil

50

85

10

1.5

80

0.3

45

Teplice N = 10

Median

51.7

66.4

33.6

1.66

94.6

0.23

42.2

Arithmetic mean

65.5

89.2

34.7

1.89

98.6

0.24

43.2

Xmax

187.0

286.0

52.1

3.17

181.0

0.40

64.1

Xmin

33.0

52.5

26.8

1.37

56.1

0.19

29.8

Standard deviation

42.4

66.4

7.4

0.61

36.5

0.06

9.5

Standard deviation [%]

64.8

74.5

21.2

32.36

37.1

24.70

21.9

Jeseník N = 5

Median

27.6

60.3

7.8

1.83

78.0

0.09

34.0

Arithmetic mean

30.3

51.9

7.5

1.89

83.3

0.14

31.5

Xmax

41.4

69.0

12.7

2.47

120.0

0.37

40.0

Xmin

16.2

28.0

3.6

1.40

35.6

0.05

16.8

Standard deviation

9.0

17.0

3.3

0.36

29.0

0.11

8.5

Standard deviation [%]

29.9

32.8

43.5

19.02

34.8

79.20

27.1

Rokycany N = 5

Median

76.7

56.5

16.3

1.72

73.1

0.20

50.8

Arithmetic mean

166.8

67.0

14.9

1.65

65.8

0.22

69.1

Xmax

584.0

136.0

20.9

1.98

87.4

0.31

176.0

Xmin

40.5

35.0

10.1

1.22

35.1

0.14

24.5

Standard deviation

209.1

35.8

4.0

0.28

19.6

0.06

55.5

Standard deviation [%]

125.4

53.5

26.7

17.18

29.7

25.87

80.3

Strakonice N = 9

Median

43.2

57.1

22.4

*

66.8

0.13

28.7

Arithmetic mean

44.0

56.8

24.0

 

66.9

0.16

32.2

Xmax

56.3

65.2

40.2

 

88.1

0.36

64.6

Xmin

29.2

45.5

13.4

 

52.5

0.06

19.9

Standard deviation

9.1

5.9

7.9

 

10.5

0.09

13.3

Standard deviation [%]

20.6

10.3

32.9

 

15.6

58.85

41.3

N – number of kindergartens
* not measured
Xmax – maximum pollutant concentration of monitored kindergartens
Xmin – minimum pollutant concentration of monitored kindergartens

Tab. 11.2a Concentration of PAHs in the kindergartens upper soil classified by US EPA as human carcinogens and probable or possible human carcinogens (Group A–C), cities of the Monitoring System

 

Concentration of PAHs [mg/kg]

Benzo[a]-
anthracene

Benzo[b]-
fluoranthene

Benzo[k]-
fluoranthene

Benzo[a]-
pyrene

Indeno-
[1,2,3-c,d]-
pyrene

Di-
benzo[a,h]-
anthracene

Chrysene

Recommended limits
for non-contaminated soil

1.00

L

L

0.10

L

L

0.01

Ústí nad Labem N = 19

Median

*

0.18

0.09

0.16

0.13

*

*

Arithmetic mean

 

0.20

0.10

0.19

0.14

 

 

Xmax

 

0.60

0.30

0.57

0.45

 

 

Xmin

 

0.04

0.01

0.03

0.03

 

 

Standard deviation

 

0.16

0.08

0.17

0.12

 

 

Standard deviation [%]

 

82.68

88.18

88.86

88.70

 

 

Jablonec nad Nisou N = 10

Median

0.47

1.50

0.60

0.62

0.61

0.25

0.67

Arithmetic mean

0.63

1.43

0.55

0.96

0.77

0.38

0.89

Xmax

1.50

3.00

0.90

2.10

1.90

1.50

1.70

Xmin

0.05

0.11

0.06

0.09

0.04

0.04

0.07

Standard deviation

0.47

0.93

0.28

0.70

0.56

0.43

0.61

Standard deviation [%]

73.85

65.27

51.72

73.52

73.44

112.05

68.94

Liberec N = 10

Median

0.26

0.39

0.20

0.38

0.22

0.32

0.29

Arithmetic mean

0.37

0.62

0.28

0.42

0.36

0.48

0.41

Xmax

1.20

3.00

0.70

1.19

1.01

1.50

1.30

Xmin

0.05

0.11

0.05

0.06

0.01

0.01

0.05

Standard deviation

0.29

0.64

0.19

0.33

0.30

0.41

0.37

Standard deviation [%]

80.07

102.58

68.93

78.54

82.39

84.61

90.16

Plzeň N = 25

Median

0.17

0.08

0.12

0.09

0.15

0.25

0.07

Arithmetic mean

0.22

0.14

0.13

0.11

0.19

0.28

0.11

Xmax

0.68

0.54

0.44

0.33

0.72

0.80

0.48

Xmin

0.01

0.03

0.01

0.02

0.02

0.06

0.01

Standard deviation

0.16

0.13

0.10

0.09

0.16

0.18

0.10

Standard deviation [%]

75.16

95.85

80.25

80.54

87.94

62.72

90.49

České Budějovice N = 21

Median

0.35

0.45

0.15

0.31

0.47

0.08

0.34

Arithmetic mean

0.51

0.60

0.19

0.41

0.57

0.09

0.44

Xmax

1.71

1.89

0.50

1.34

1.82

0.28

1.14

Xmin

0.02

0.07

0.02

0.01

0.06

0.01

0.04

Standard deviation

0.46

0.52

0.15

0.35

0.48

0.08

0.35

Standard deviation [%]

89.71

86.67

80.61

85.76

84.67

82.35

80.55

N – number of kindergartens
L – limit is not set
* not measured
Xmax – maximum pollutant concentration of monitored kindergartens
Xmin – minimum pollutant concentration of monitored kindergartens

Tab. 11.2b Concentration of PAHs in the kindergartens upper soil classified by US EPA as human carcinogens and probable or possible human carcinogens (Group A–C), associated cities

 

Concentration of PAHs [mg/kg]

Benzo[a]-
anthracene

Benzo[b]-
fluoranthene

Benzo[k]-
fluoranthene

Benzo[a]-
pyrene

Indeno-
[1,2,3-c,d]-
pyrene

Di-
benzo[a,h]-
anthracene

Chrysene

Recommended limits
for non-contaminated soil

1.00

L

L

0.10

L

L

0.01

Teplice N = 10

Median

*

0.46

0.22

0.45

0.32

*

*

Arithmetic mean

 

0.48

0.23

0.48

0.35

 

 

Xmax

 

1.11

0.53

1.16

0.80

 

 

Xmin

 

0.06

0.03

0.06

0.04

 

 

Standard deviation

 

0.29

0.14

0.32

0.22

 

 

Standard deviation [%]

 

60.90

61.60

65.20

61.50

 

 

Rokycany N = 10

Median

0.48

0.23

0.23

0.23

0.23

0.43

0.28

Arithmetic mean

0.58

0.32

0.28

0.40

0.22

0.46

0.40

Xmax

0.96

0.80

0.65

1.01

0.33

0.84

0.79

Xmin

0.38

0.09

0.07

0.05

0.03

0.14

0.26

Standard deviation

0.21

0.25

0.20

0.34

0.10

0.23

0.20

Standard deviation [%]

35.70

79.40

70.00

85.60

47.40

49.10

50.80

Strakonice N = 10

Median

0.62

0.74

0.24

0.50

0.69

0.10

0.63

Arithmetic mean

0.65

0.78

0.25

0.50

0.66

0.08

0.51

Xmax

1.29

1.50

0.44

0.93

1.21

0.15

0.83

Xmin

0.08

0.10

0.06

0.04

0.14

0.01

0.07

Standard deviation

0.42

0.48

0.14

0.31

0.37

0.05

0.27

Standard deviation [%]

65.10

61.80

57.30

62.60

56.00

56.90

53.50

N – number of kindergartens
L – limit is not set
* not measured
Xmax – maximum pollutant concentration of monitored kindergartens
Xmin – minimum pollutant concentration of monitored kindergartens

Tab. 11.3a Estimate of share of soil ingestion on the total oral daily intake [in % of exposure limit]

 

Lead [% PTWI]

Arsenic [% PTWI]

Arsenic [% RfD]

Median
estimate

Maximum
estimate

Median
estimate

Maximum
estimate

Median
estimate

Maximum
estimate

Ústí nad Labem

7

11

6

8

39

54

Šumperk

6

11

3

5

21

31

Jablonec nad Nisou

20

33

5

8

35

54

Liberec

20

17

5

7

38

52

Plzeň

20

14

5

7

38

50

České Budějovice

20

17

2

3

17

23

 

 

Teplice

12

20

12

19

87

133

Jeseník

6

13

2

5

19

32

Rokycany

20

42

5

10

37

67

Strakonice

9

16

8

13

58

92

Tab. 11.3b Carcinogenic risk estimate from soil ingestion

 

Individual lifetime cancer risk – arsenic

Individual lifetime cancer risk – benzo[a]pyrene

Median estimate

Maximum estimate

Median estimate

Maximum estimate

Ústí nad Labem

1.52*10-5

2.08*10-5

6.24*10-7

1.15*10-6

Šumperk

7.92*10-6

1.21*10-5

2.16*10-6

5.14*10-6

Jablonec nad Nisou

1.35*10-5

2.07*10-5

3.22*10-6

7.63*10-6

Liberec

1.47*10-5

1.99*10-5

1.39*10-6

2.59*10-6

Plzeň

1.48*10-5

1.94*10-5

3.84*10-7

6.72*10-7

České Budějovice

6.59*10-6

8.85*10-6

1.15*10-6

2.11*10-6

 

 

Teplice

3.36*10-5

5.14*10-5

1.78*10-6

4.27*10-6

Jeseník

6.69*10-6

1.22*10-5

1.92*10-6

6.53*10-6

Rokycany

1.42*10-5

2.60*10-5

1.25*10-6

4.18*10-6

Strakonice

2.25*10-5

3.53*10-5

1.68*10-6

4.18*10-6

Legend for Tables 11.3a, b:
Median estimate – based on the median value of pollutant concentration in kindergartens
Maximum estimate – based on the maximum value of pollutant concentration out of monitored kindergartens

Fig. 11.1a Lead concentration in upper soil of kindergartens
Fig. 11.1b Arsenic concentration in upper soil of kindergartens
Fig. 11.2 Benzo[a]pyrene concentration in upper soil of kindergartens
Fig. 11.3 Hazard index of arsenic intake from soil ingestion

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