MONITORING OF PERSISTENT ORGANIC POLLUTANTS IN SOILS OF THE CZECH REPUBLIC Milan Sáňka1), Jiří Zbíral2), Karel Provazník2), Šárka Poláková2) 1)
Centre for Environment and Land Assessment EKOTOXA s.r.o. Kosmákova 28, 615 00 Brno, tel.: +420 549 241 411, e-mail:
[email protected], 2) The Central Institute for Supervising and Testing in Agriculture, Hroznová 2, 656 06 Brno, e-mail:
[email protected],
[email protected] Introduction Soil survey, monitoring and inventarization programs are inevitable tools to define soil properties for a given area (country), including the status of pollution. Most European countries have developed their own monitoring system focused on the main soil characteristics. Agricultural purposes were emphasised but environmental interests are becoming to play more and more important role in these systems. That is why also potentially toxic substances, including persistent organic pollutants (POPs) are being introduced into monitoring systems. In the Czech Republic the systematic monitoring of POPs is carried out on two levels: 1. As a part of basal soil monitoring scheme (BSMS) on permanent plots on agricultural soil and in protected areas (conducts Central Institute for Supervising and Testing in Agriculture), 2. Monitoring for specific purposes in order to find the sources and levels of POPs in different areas and to propose some remediation measures (conducts Research Institute for Land Reclamation and Soil Conservation). The system and results of BSMS is the object of this contribution. The BSMS became a part of the Czech legislation by accepting the Act on fertilisers No. 156/98 S.B. (in wording of later regulations) and connected decrees as a tool supporting decision-making process in state administration. Evaluation and continuous assessment of both levels of monitoring is carried out and submitted to the Ministry of Agriculture and the Ministry of Environment. Figure 1. Location of permanent POPs monitoring plots in the Czech Republic.
Materials and method The program of monitoring is being realized in different types of land use on agricultural soil (arable land, grassland, special crops) since 1992. The irregular network consists of 189 representative monitoring plots in standard conditions, 27 monitoring plots in highly polluted areas and of 40 monitoring plots on undisturbed soil in protected areas. The contents of selected POPs (table 1) are monitored on 35 plots on agricultural land (chosen from 189 standard condition plots and from 27 contaminated plots) and on 5 plots in the protected areas (figure 1). The sampling period is one-year. Each monitoring plot both in the agricultural and protected areas subsystem is a rectangle covering an area of 1000m2 (25 x 40m). Individual samples are taken from each sampled layer according to the scheme in figure. 2. The individual subsamples are bulked to provide approximately one kilogram of a composite soil sample from each sampled layer. There are two sampled layers on agricultural soils: plough layer and subplough layer with the thickness of the plough layer according to the particular conditions on the plot. The maximum depth of a subplough layer is up to 60 cm. Ten centimetres of soil between the two sampled layers is excluded. Within the protected areas subsystems the soil is sampled according to A and B soil genetic horizons. Figure 2: Scheme for soil sampling on the monitoring plot.
In the period of 1994 – 1997 only the plots with wheat on agricultural soils were sampled (i.e. the set of plots was different each year). Since 2000 the plots given in figure 1 are sampled each year, regardless the crop. More details are in table 1. Table 1. List of individual POPs analysed in BSMS samples each year substance Atrazin and its metabolites deethylatrazin deisopropylatrazin Persistent organochlorinated pesticides and their metabolites αHCH, βHCH, γHCH HCB o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, p,p'-DDT Polychlorinated biphenyls (PCB) congeners 138, 153, 180 congeners 138, 153, 180, 28, 52, 101 congeners 138, 153, 180, 28, 52, 101, 118 Polycyclic aromatic hydrocarbons (PAH) 16 individual hydrocarbons according to the EPA list
period till 1996 incl. till 1996 incl. 1994-97, since 2000 1994-97, since 2000 1994-97, since 2000 since 1994 since 1998 since 2000 since 1997
Results and conclusions The basic statistical characteristics for the contents of all observed POPs during the whole period of monitoring are given in table 2. Only data for arable soil (both plough layer and subsoil) were processed statistically since there has not been enough data for other types of land use in individual years yet.
Table 2. Basic statistical characteristics for contents of POPs on arable soil. (µg.kg-1) 1) 2) HCB DDT3) DDE3) descriptive Sum of PAH Sum of PCB year statistics P S P S P S P S P S 1995 1996 1997 1998 1999 2000 2001 2002
DDD3) P S
ar. mean
-
-
1,1
1,6
5,6
3,1
19,2
12,4
10,9
7,9
2,5
1,6
median
-
-
0,8
0,8
5,7
2,6
15,4
10,1
12,0
6,3
1,2
0,8
ar. mean
-
-
1,9
1,1
5,2
2,4
26,8
15,5
11,4
7,6
2,6
1,3
median
-
-
0,8
0,8
6,1
1,9
21,4
8,8
10,7
6,2
2,1
1,0
ar. mean
986
433
7,9
3,5
8,2
6,4 114,6
54,4
72,2
22,3
9,6
6,8
median
667
323
0,8
0,8
7,2
4,4
37,4
17,0
19,8
14,6
