11. HEALTH RISKS FROM URBAN SOIL POLLUTION |
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 and microbial agents through ingestion of soil and soil dust. In view of that the greatest probability of increased exposure to noxious substances from contaminated soil is in the child population, the project is focused on kindergarten playgrounds.
In the year 2002 there have been carried out samplings of soil and assessments of its contamination in 47 kindergartens in selected towns and cities, namely in 10 kindergartens of Klatovy, in 10 of Kroměříž, and in 27 of Hradec Králové. There have thus been covered all kindergartens within the cadasters of the cities under monitoring. The methodology of upper soil sampling was the same as in previous years, namely to a depth of 10 cm at five sampling points at each kindergarten site, which had been selected in view of the most frequent presence of the children there. Upon homogenization of the samples from the sampling points the samples were analyzed for selected noxae.
In the year 2002 there have been also carried out repeated samplings and analyses of soil samples for microbiological and parasitological determinations at 19 kindergartens in Olomouc and 2 in Karviná. Those kindergartens were selected on the basis of microbial and parasite contamination found within the framework of monitoring in the year 2001. In the repeated samplings there have been analyzed composite as well as individual samples.
11.2 Monitored factors
In the upper soil of kindergarten playgrounds the following factors were followed up:
Samples of upper soil were taken and processed according to Standard Operational Procedures elaborated within the framework of an associative study, namely for taking, storage and transport of samples of soil and particulate fall-out matter, for the analytical determination of selected metals and organic substances in soil, for microbiological determinations of selected microorganisms and for the parasitological investigation of soil. Soil samples for chemical, microbiological and parasitological analyses were taken in the period of May–September 2002. Elemental analyses were carried out by x-ray fluorescence (RTF) except for beryllium and mercury which were assessed by atomic absorption spectrometry (AAS). Polycyclic aromatic hydrocarbons were analyzed by high-pressure liquid chromatography (HPLC).
11.3 Levels of upper soil contamination
11.3.1 Toxic metals and trace elements
The concentrations of metals in upper soil layers in kindergartens vacillated within a wide range of values. Results are presented in Table 11.1, wherein there are presented basic statistical parameters of the presence of the elements under follow-up in upper soil at all the kindergartens under study. For comparison there are also presented the parameters in kindergartens followed up in the previous period of monitoring.
In Klatovy the cadmium level has been found to exceed the recommended limit set in the bill of the Decree of the Ministry Of Health No. 464/2000 Dig amendment, in all 10 kindergartens; that of arsenic in 9 kindergartens (i.e. 90 %), that of lead in 4 kindergartens (40 %), and that of vanadium in 6 kindergartens (60 %). The other elements ranged below the recommended limit. Likewise, in Kroměříž the detected upper soil cadmium levels exceeded the limit in all 10 kindergartens, lead levels in two (20 %), beryllium and arsenic in one (10 %). The other elements ranged below the recommended limit value. In Hradec Králové, in 23 kindergartens (85 %) was exceeded the recommended limit for upper soil cadmium, in 9 kindergartens (33 %) for arsenic, and in one (4 %) for lead. The other elements ranged below the recommended limits. The share of kindergartens with findings exceeding the recommended limits for cadmium, arsenic, and lead in their upper soil in the above-mentioned cities and in kindergartens followed up in the year 2001 – Olomouc and Karviná – is presented in Fig. 11.1. From that Figure it is apparent that from the point of view of kindergartens with above-limit findings, the most unfavorable situation is in Karviná followed by Klatovy. On the other hand, the most favorable situation in that respect is in Hradec Králové.
The characteristics of levels of selected elements in the soil of kindergartens in Klatovy, Kroměříž, Hradec Králové, Olomouc and Karviná have been treated in Fig. 11.2a-c. Concerning the levels of cadmium (Fig. 11.2a), in all the cities even the lowest values found exceeded the recommended limit. The highest levels were found in the kindergartens of Karviná and Kroměříž. In Karviná the median of the levels found reaches twice the limit, in Kroměříž and Klatovy the median of the levels found approximate twice the limit. In arsenic (Fig. 11.2b) the highest average load was found in the kindergartens of Klatovy, however, the highest levels were found in several kindergartens of Hradec Králové and Olomouc. As far as lead contamination of the upper soil is concerned (Fig. 11.2c), the most unfavorable situation was found in Olomouc where several kindergartens with high levels have been found, followed by Karviná and Klatovy.
11.3.2 Polycyclic aromatic hydrocarbons (PAHs)
Results of PAHs determination in the upper soil at kindergartens are presented in Tab. 11.2 which includes basic statistical parameters for polycyclic aromatic hydrocarbons classified by the US EPA as carcinogenic. The values found for benzo[a]pyrene and benzo[a]anthracene in the kindergartens followed up in 2002 as well as those in the year 2001 (Olomouc, Karviná) have been processed in Figs. 11.3a and 11.3b.
In Klatovy, in the case of naphthalene, acenaphthylene, phenanthrene, pyrene, fluorene, chrysene, indeno[1,2,3-c,d]pyrene, and di-benz[a,h]anthracene the values in all the kindergartens were below their detection limits; acenaphthylene was in the range of 0.147–0.0025 mg/kg, anthracene 0.0025–0.206, benzo[a]anthracene 0.0137–2.33, benzo[b]fluoranthene 0.091–2.251, benzo[k]fluoranthene 0.027–0.623, benzo[a]pyrene 0.051–1.917, benzo[g,h,i]perylene 0.04–0.674 mg/kg. In Kroměříž the levels of acenaphtylene in all the kindergartens were below the detection limit; naphthalene ranged 0.105–2.13, acenaphthene 0.025–0.297, fluorene 0.137–0.025, phenanthrene 0.132–2.00, anthracene 0.0087–0.2, fluoranthene 0.202–4.1, pyrene 0.104–2.17, chrysene 0.041–0.867, benzo[a]anthracene 0.073–1.37, benzo[b]fluoranthene 0.107–1.54, benzo[k]fluoranthene 0.0423–0.812, benzo[a]pyrene 0.119–1.3, indeno[1,2,3-c,d]pyrene 0.064–0.942, di-benz[a,h]anthracene 0.014–0.239, and benzo[g,h,i]perylene 0.041–0.586 mg/kg. In Hradec Králové, in all the kindergartens the levels of naphthalene, acenaphthylene, acenaphthene, and fluorene were lower than their detection limits. The levels of phenanthrene ranged 0.005–1.06, anthracene 0.005–0.429, fluoranthene 0.023–1.47, pyrene 0.028–1.45, chrysene 0.019–0.628, benzo[a]anthracene 0.02–0.637, benzo[b]fluoranthene 0.027–0.637, benzo[k]fluoranthene 0.005–0.411, benzo[a]pyrene 0.016–0.384, indeno[1,2,3-c,d]pyrene 0.005–0.496, di-benz[a,h]anthracene 0.005–0.295, and benzo[g,h,i]perylene 0.005-0.614 mg/kg.
The concentration characteristics of selected PAHs are presented in Fig. 11.3a-b. The most unfavorable situation in kindergarten soil pollution with benzo[a]pyrene (11.3a) was found in Olomouc, namely in quantity as well as in the frequency of exceeding the recommended limit value. In Karviná and Klatovy the situation is characterized by the same value of the arithmetical mean. The lowest benzo[a]pyrene load was found in Hradec Králové. In view of the ten-fold recommended limit for benzo[a]anthracene the situation in the pollution with this substance is more favorable (Fig. 11.3b). Just as with the other polycyclic aromatic hydrocarbons, the most contaminated kindergarten soil with benzo[a]anthracene is in Olomouc, somewhat less in Karviná and Klatovy.
11.3.3 Indicators of microbial contamination
In the year 2002 there have been performed upper soil analyses for microbial pollution indicators in 9 kindergartens in Klatovy, in 10 kindergartens in Kroměříž, and in 10 kindergartens in Hradec Králové. The analyses were performed with composite samples. Sampling took place in the period April through October 2002. Followed up was the presence of salmonellae, thermotolerant coliforms, enterococci, geohelminth ova, as well as yeast and mould counts.
The classification of the kindergartens according to soil contamination levels on the basis of composite samples from upper soil in their playgrounds within the framework of monitoring (Hradec Králové, Klatovy, Kroměříž) is presented in Tabs. 11.3 and 11.4a, b, c, (for comparison supplemented with data from kindergartens in Olomouc and Karviná that were under monitoring in the two preceding years). The limit values for indicator levels of fecal microbial and parasitic pollution in the three cities under follow-up in 2002 were exceeded in 47.8 % of all kindergartens under study. The limit value of 102 CFU/g dry matter for thermotolerant coliforms was exceeded in 8 (17.4 %) kindergartens, for enterococci in 14 (30.4 %) of them. Findings for moulds and yeasts in the kindergartens under follow-up varied in 23.9 % soil samples from kindergartens in the range 102 to 103 CFU/g dry matter, in 76.1 % soil samples that being in the range of 103–104 CFU/g dry matter. Contamination with geohelminths pathogenic to humans was found in 17.4 % of kindergartens under follow-up. Salmonella pollution has not been detected.
The task of the partial study was the assessment a sampling strategy of sand and soil from children’s playgrounds for the determination of geohelminths and microbial indicators of fecal pollution with the aim of verifying the duration of contamination and to assess to what degree an individual sample can influence the results derived from a composite sample taken from the kindergarten environs. There have been made composite samplings at 19 kindergartens in Olomouc where there had been recorded microbial and parasitic pollution in previous investigations, and at 2 where there had not been detected any. Simultaneously, there have been analyzed in 11 kindergartens (10 polluted and one not polluted) 4 additional individual samples for comparison of the degree of pollution in the individual and in the composite soil samples. In Karviná there has been tested for an assessment of the degree of contamination of individual and composite samples at one kindergarten that had in the past been found to be contaminated with parasites, and at one that had in the past been found to be polluted with a microbial agent. Ten individual soil samples and one composite sample were analyzed. Through composite samples a persisting contamination after a year (2001) or after two years (2000) has been confirmed in 9 cases out of the 19 contaminated localities under follow-up in Olomouc. Likewise, persistent contamination has been found in the kindergartens in Karviná. A study in which there is being followed up an assessment of the degree of pollution of individual samples and of composite samples shall continue and its evaluation shall be carried out upon the finalization of the follow-up in the remaining cities. There have been taken into account the conclusions of a comparative study (Carabin et al., 1998, see Chapter 14) focused on the assessment of three different strategies in sand and soil sampling from children’s playgrounds for the determination of Toxocara spp. ova and fecal coliform counts. Sampling was conducted by the method of random selection along with the application of two resolving methods. The first resolving method was based on the selection of sites where there was expected the greatest frequency of voidung by animals, the second one was based on the selection of sites where children played most frequently. The authors of that study found that the most representative results were obtained by analyzing composite samples, namely of samples taken from the whole surface of the facility. Results of analyses of individual samples or samples taken on the basis of discrimination analysis were less representative.
11.4 Partial conclusions
Significant exceeding of the recommended levels for non-contaminated soil was found in the upper soil of playgrounds at kindergartens in the cities under follow-up with regard to cadmium, arsenic and lead. As regards cadmium, that was exceeded in all the kindergartens under study in Klatovy and Kroměříž and in 85 % of them in Hradec Králové. As to arsenic, the recommended limit concentrations were exceeded in 90 % of kindergartens in Klatovy, in 33 % of them in Hradec Králové, the least contamination with arsenic being found in Kroměříž with only one kindergarten having the limit exceeded. Likewise, the limit value of lead was exceeded the most in Klatovy (in 40 % of kindergartens). Also higher levels were found of vanadium in Klatovy. As to other metals, higher levels were found only singularly.
The contamination of upper soil with polycyclic aromatic hydrocarbons in the urban environment is significant from the point of view of importance to health in unintentional ingestion of soil. Markedly higher contamination levels of the soil in all the cities under follow-up were found as regards benzo[a]pyrene which is considered to be the most serious health hazard of the PAH group of compounds. Levels exceeding the recommended limits were found in benzo[a]pyrene in the upper soil of about 90 % of the kindergartens, in benzo[a]anthracene in 20 %, and in anthracene in 60 % of the kindergartens under study. Markedly higher contamination levels of the soil with PAHs were found in Kroměříž. There have been found levels of all the PAHs under follow-up to be higher than the recommended limits for soil in all the kindergartens under study, except for one. In Klatovy the majority of values were lower than the detection limit except for anthracene, benzo[a]pyrene, and benzo[a]anthracene. In Hradec Králové, the recommended limit values for chrysene have been exceeded in all the kindergartens under study, for fluoranthene in 70 % of kindergartens, in 63 % for anthracene, and in 33 % of them for benzo[a]pyrene.
In almost half of the kindergartens under study, there have been found higher values of microbiological contamination of the upper soil than allowed by criteria in Decree No. 464/2000 Dig. of the Ministry of Health.
In view of results obtained by monitoring of microbial pollution by the taking and analysis of composite samples, it seems appropriate in the next phase of the study to finalize the investigation of pollution in the form of a network of individual samples and simultaneously to find any persistence and origin of pollution through questionnaires. For the demonstration of the effect of pollution of the upper soil on the health of children there shall be conducted a study, in the year 2003, in kindergartens in which there has been repeatedly confirmed microbial and parasitic contamination, as well as in kindergartens in which there has never been found any such pollution.
Table 11.1 Upper soil elements content in the kindergartens of monitored cities
|
Element concentration [mg/kg] |
|||||||
Pb |
Cd |
Cu |
Cr |
As |
Be |
V |
Hg |
|
Proposed limits |
50.00 |
0.30 |
45.00 |
85.00 |
10.00 |
1.50 |
80.00 |
0.30 |
Klatovy N = 10 |
||||||||
Median value |
6.55 |
0.48 |
27.90 |
57.84 |
13.43 |
0.01 |
85.15 |
0.14 |
Mean value (arithm.) |
47.84 |
0.51 |
28.84 |
55.14 |
13.76 |
0.02 |
82.56 |
0.15 |
Xmax |
73.11 |
0.71 |
44.49 |
68.79 |
17.81 |
0.05 |
105.91 |
0.25 |
Xmin |
36.16 |
0.40 |
19.76 |
38.34 |
9.93 |
0.01 |
50.43 |
0.09 |
Standard deviation |
10.31 |
0.10 |
8.41 |
9.76 |
2.11 |
0.02 |
14.29 |
0.05 |
Standard deviation [%] |
21.56 |
20.49 |
29.17 |
17.70 |
15.36 |
79.61 |
17.31 |
35.70 |
Kroměříž N = 10 |
||||||||
Median value |
28.00 |
0.50 |
24.40 |
47.60 |
7.20 |
1.00 |
46.80 |
0.10 |
Mean value (arithm.) |
36.35 |
0.53 |
27.12 |
50.68 |
7.40 |
1.04 |
48.89 |
0.17 |
Xmax |
83.17 |
1.18 |
43.22 |
65.28 |
10.46 |
1.60 |
67.28 |
0.72 |
Xmin |
21.76 |
0.41 |
19.21 |
40.68 |
5.61 |
0.67 |
36.97 |
0.04 |
Standard deviation |
20.93 |
0.24 |
8.11 |
9.64 |
1.68 |
0.27 |
9.22 |
0.20 |
Standard deviation [%] |
57.58 |
44.49 |
29.91 |
19.02 |
22.64 |
25.76 |
18.86 |
115.21 |
Hradec Králové N = 27 |
||||||||
Median value |
30.57 |
0.4 |
11.65 |
17.57 |
8.68 |
0.03 |
14.07 |
0.07 |
Mean value (arithm.) |
31.23 |
0.38 |
14.28 |
20.71 |
9.08 |
0.25 |
17.29 |
0.08 |
Xmax |
75.81 |
0.61 |
33.68 |
55.11 |
24.68 |
1.48 |
52.33 |
0.23 |
Xmin |
16.81 |
0.15 |
8.27 |
10.08 |
3.82 |
0.01 |
5.00 |
0.03 |
Standard deviation |
11.45 |
0.11 |
6.1 |
10.39 |
4.12 |
0.41 |
11.32 |
0.05 |
Standard deviation [%] |
36.65 |
29.83 |
42.71 |
50.15 |
45.43 |
166.70 |
65.48 |
56.71 |
Olomouc N = 45 |
||||||||
Median value |
46.60 |
0.41 |
29.00 |
54.20 |
8.20 |
0.85 |
58.00 |
BD |
Mean value (arithm.) |
51.10 |
0.39 |
32.00 |
49.80 |
8.50 |
0.87 |
55.20 |
|
Xmax |
106.70 |
0.66 |
111.80 |
75.30 |
22.30 |
1.41 |
86.10 |
|
Xmin |
28.50 |
0.20 |
12.10 |
21.10 |
4.20 |
0.52 |
21.50 |
|
Standard deviation |
19.04 |
0.12 |
15.31 |
15.54 |
2.60 |
0.15 |
16.38 |
|
Standard deviation [%] |
37.26 |
32.40 |
47.93 |
31.18 |
30.73 |
17.50 |
29.66 |
|
Karviná N = 25 |
||||||||
Median value |
46.80 |
0.61 |
20.10 |
58.20 |
9.10 |
1.88 |
52.20 |
BD |
Mean value (arithm.) |
48.20 |
0.68 |
22.00 |
55.70 |
9.10 |
1.93 |
52.70 |
|
Xmax |
84.50 |
1.32 |
38.80 |
68.40 |
12.60 |
2.80 |
65.30 |
|
Xmin |
30.80 |
0.40 |
15.10 |
38.40 |
6.20 |
1.20 |
33.00 |
|
Standard deviation |
10.31 |
0.24 |
5.84 |
6.64 |
1.47 |
0.37 |
6.74 |
|
Standard deviation [%] |
21.39 |
34.98 |
26.48 |
11.92 |
16.11 |
20.92 |
12.79 |
|
N – number of kindergartens
BD: > 50 % of samples under the bound of determination
Table 11.2 Upper soil content of PAHs classified by US EPA as human carcinogens and probable or possible human carcinogens (Group A–C) in kindergartens
|
PAHs [mg/kg] |
||||||
Benzo[a]- |
Benzo[b]- |
Benzo[k]- |
Benzo[a]- |
Indeno- |
Di-benz |
Chrysene |
|
Proposed limits |
1.00 |
L |
L |
0.10 |
L |
L |
0.01 |
Klatovy N = 9 |
|||||||
Median value |
0.16 |
0.34 |
0.12 |
0.24 |
BD |
BD |
BD |
Mean value (arithm.) |
0.51 |
0.58 |
0.20 |
0.49 |
|
|
|
Xmax |
2.33 |
2.25 |
0.62 |
1.92 |
|
|
|
Xmin |
0.01 |
0.09 |
0.03 |
0.05 |
|
|
|
Standard deviation |
0.76 |
0.67 |
0.18 |
0.56 |
|
|
|
Standard deviation [%] |
149.73 |
115.60 |
91.67 |
112.66 |
|
|
|
Kroměříž N = 10 |
|||||||
Median value |
0.19 |
0.21 |
0.10 |
0.19 |
0.15 |
0.03 |
0.10 |
Mean value (arithm.) |
0.33 |
0.37 |
0.19 |
0.33 |
0.25 |
0.06 |
0.19 |
Xmax |
1.37 |
1.54 |
0.81 |
1.30 |
0.94 |
0.24 |
0.87 |
Xmin |
0.07 |
0.11 |
0.04 |
0.12 |
0.06 |
0.01 |
0.04 |
Standard deviation |
0.38 |
0.41 |
0.22 |
0.34 |
0.25 |
0.07 |
0.24 |
Standard deviation [%] |
113.39 |
110.40 |
116.30 |
104.40 |
101.50 |
111.30 |
123.00 |
Hradec Králové N = 27 |
|||||||
Median value |
0.11 |
0.14 |
0.05 |
0.09 |
0.09 |
0.04 |
0.09 |
Mean value (arithm.) |
0.16 |
0.17 |
0.08 |
0.12 |
0.13 |
0.07 |
0.18 |
Xmax |
0.64 |
0.64 |
0.41 |
0.38 |
0.50 |
0.30 |
0.63 |
Xmin |
0.02 |
0.03 |
0.01 |
0.02 |
0.01 |
0.01 |
0.02 |
Standard deviation |
0.16 |
0.14 |
0.09 |
0.10 |
0.12 |
0.07 |
0.17 |
Standard deviation [%] |
99.70 |
85.40 |
112.20 |
82.00 |
90.30 |
102.90 |
97.80 |
Olomouc N = 47 |
|||||||
Median value |
0.34 |
0.43 |
0.45 |
0.61 |
0.36 |
0.09 |
0.50 |
Mean value (arithm.) |
0.92 |
1.54 |
1.13 |
1.65 |
1.34 |
0.15 |
1.49 |
Xmax |
7.69 |
18.67 |
11.01 |
18.88 |
19.86 |
1.50 |
15.92 |
Xmin |
0.04 |
0.05 |
0.04 |
0.05 |
0.04 |
0.04 |
0.05 |
Standard deviation |
1.65 |
3.12 |
2.03 |
3.33 |
3.07 |
0.35 |
2.85 |
Standard deviation [%] |
179.80 |
202.20 |
180.30 |
201.90 |
28.70 |
233.20 |
192.00 |
Karviná N = 25 |
|||||||
Median value |
0.32 |
0.34 |
0.17 |
0.31 |
0.31 |
0.05 |
0.18 |
Mean value (arithm.) |
0.53 |
0.52 |
0.27 |
0.49 |
0.49 |
0.07 |
0.31 |
Xmax |
2.39 |
1.62 |
0.90 |
1.82 |
1.59 |
0.28 |
1.21 |
Xmin |
0.09 |
0.11 |
0.05 |
0.09 |
0.01 |
0.01 |
0.05 |
Standard deviation |
0.55 |
0.45 |
0.24 |
0.45 |
0.44 |
0.07 |
0.32 |
Standard deviation [%] |
103.30 |
86.00 |
89.80 |
92.20 |
89.40 |
96.60 |
101.60 |
N – number of kindergartens
L – limit is not set
BD: > 50 % of samples under the bound of determination
Table 11.3 Distribution of the kindergartens according to the microbial contamination of the upper soil
|
Distribution of the kindergartens according to upper soil microbiological contamination |
|||||
< 101 CFU |
101–102* CFU |
102–103 CFU |
103–104 CFU |
104–105 CFU |
> 105 CFU |
|
Klatovy N = 9 |
||||||
Thermotolerate colif. bacteria |
1 |
4 |
3 |
1 |
/ |
/ |
Enterococci |
/ |
7 |
1 |
1 |
/ |
/ |
Yeasts, fungi |
/ |
/ |
/ |
9 |
/ |
/ |
Kroměříž N = 10 |
||||||
Thermotolerate colif. bacteria |
10 |
/ |
/ |
/ |
/ |
/ |
Enterococci |
1 |
4 |
5 |
/ |
/ |
/ |
Yeasts, fungi |
/ |
/ |
10 |
/ |
/ |
/ |
Hradec Králové N = 27 |
||||||
Thermotolerate colif. bacteria |
18 |
5 |
3 |
1 |
/ |
/ |
Enterococci |
15 |
5 |
6 |
1 |
/ |
/ |
Yeasts, fungi |
/ |
/ |
1 |
26 |
/ |
/ |
Olomouc N = 47 |
||||||
Thermotolerate colif. bacteria |
/ |
42 |
5 |
/ |
/ |
/ |
Enterococci |
/ |
33 |
13 |
1 |
/ |
/ |
Yeasts, fungi |
/ |
/ |
/ |
2 |
26 |
19 |
Karviná N = 25 |
||||||
Thermotolerate colif. bacteria |
4 |
13 |
6 |
1 |
1 |
/ |
Enterococci |
3 |
17 |
2 |
3 |
/ |
/ |
Yeasts, fungi |
/ |
/ |
/ |
/ |
24 |
1 |
N – number of kindergartens
* 102 CFU: public health limit value for thermotolerant coliform bacteria
and enterococci set in Regulation No. 464/2000 of the Ministry of Health,
suppl. No. 8 – evaluation of fecal pollution in playing fields.
The findings of Salmonella in upper soil were negative in all samples.