**Soil Contamination Health Risks in Czech Proposal of Soil Protection Legislation**

Radim Vácha, Milan Sáňka, Jan Skála, Jarmila Čechmánková and Viera Horváthová

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/62456

#### **Abstract**

A new system of soil contamination limit values proposed for Czech legislation is described. The system is based on the hierarchical limit values system with two levels. The first one—prevention limit—defined background values of risk elements (REs) and persistent organic pollutants (POPs) in Czech agricultural soils supported by the data from soil monitoring system. The second one—indication limit—is defined for human health protection by two principles, the protection of food chain and the protection of direct human health risks by inhalation, dermal and oral intake of RE and POPs in soil particles on the field. The practical application of limit values proposal was applied in the project focused on soil contamination influence on health and environmental risks in fluvial zones of Czech important river basins. The floodplain soils belong to the most contaminated soils in Europe generally and the project defined the potential fluvial areas with increased human health risks.

**Keywords:** soil contamination, health risks, risk elements, persistent organic pollu‐ tants, soil protection legislation

### **1. Introduction**

The one of the important way of contamination risk elimination is the existence of legislative norms of contaminants in the environment. The soil is medium where the load from other environments can concentrate and interact. The limit values of main contaminants (risk elements (REs) and persistent organic pollutants (POPs) predominantly) were set in most of developed countries worldwide including the Czech Republic. The limits of REs and POPs concentra‐

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tions in agricultural soil are set by the Decree No. 13/1994 Coll. in the Czech legislation [1]. These limit values have a status of maximum tolerable values in agricultural soils. The criteria were derived from available data in the Czech Republic at the beginning of 90th and the data were corresponding with the load of Czech agricultural soils and also of some European countries. The REs limit values stated in the decree were derived as rounded 90 percentile of the back‐ ground values in soil (pseudototal content in extract of Aqua regia). Some authors [2, 3] published the data concerning the total content of REs in the Czech soils before the proposal of back‐ ground values of REs in Czech agricultural soils [4] was given. The history of POPs limit values assessment was different. The POPs limits were derived from available external data (especial‐ ly from the Netherlands) since no relevant data for the Czech soils were available in 1994. As a result, limit values of some individual polycyclic aromatic hydrocarbons in the Decree No. 13/1994 Coll. are lower than their real background values in Czech agricultural soils proposed later [5]. This situation is misapplied by subjects demanding appropriation of agricultural land for construction purposes because there are assessed lower levies for the appropriation in the cases where the limit values are exceeded.

The described limit values were derived statistically and do not represent any specific risk in fact. The delimitation of soil suitability for agricultural use by the existence of one value of risk substance concentration is very questionable. For these reasons, the presented version of limit values can be considered as behind the time. The new version of limit values was proposed [6] and it is based on the principle of hierarchical limit values, differentiated in three levels. These individual levels present specific risks. The first one is derived from the background values of RE (POPs, respectively) in agricultural soils and the principles of limit construction follow German experiences [7], Regulation BGBl I, No. 36/1999 [8]. The principles of the assessment of nationals' soil background values of REs presented by [9] include following steps: The assessment of natural background given by the geology—REs contents in rocks and parent materials and REs contents in organic matter of soils; the assessment of diffusion load given by atmospheric deposition especially (determined the background values of organic pollu‐ tants) and the definition of practical questions connected with soil use and its relationship to environmental protection level. The suitable statistical methods for the assessment of element background levels in soils (defined as the first level) and of the higher levels of soil limits were described in detail in previous study [10].

The second level of limit values can be defined for specific risks (transfer into plants, transfer into ground water, or microbial activity inhibition for example). Considering the limits for transfer into plants, the Czech legislation proposal follows the German approach [11] using single extraction methods (1 mol/L NH4NO3, 0.01mol/L CaCl2) which were scientifically verified by several studies [12–15].

The third level of limit values is directly connected with an impact on human health (Maximum Permissible Concentrations—MPC in the Netherlands, Contaminated Land Exposure Assess‐ ment in Great Britain) or the threat of ground water contamination (US EPA) generally. The applications of soil decontamination technologies must be used when these limit values are exceeded. The limit for Czech legislation was based on the US EPA methodology [16]. The protection of direct human health risk by inhalation, dermal, and oral intake is based on the fact that zootoxic RE and POPs can cause the kind of mentioned risks to farmers spending the time on the field during agro technical activities. The zootoxic RE (As, Cd, Hg, Pb, and Tl) and POPs substances (sum of PAHs, benzo(a)pyrene, sum of 7 PCBs, sum of DDTs, HCB, HCH, and PCDDs/Fs) were chosen for their known negative impact on human health. The EPA methodology was applied for limit values calculation based on the toxicity of individual RE or POP substance (defined carcinogenic risk by WHO), the general soil properties and expected time period spending by the farmer on the field.

The limit values system is in legislative process in current days and validity is presumed since 2016. The practical application of limit values proposal was verified in the project focused on soil contamination influence on health and environmental risks in fluvial zones of Czech important river basins. The floodplain soils belong to the most contaminated soils in Europe generally and the project defined the potential fluvial areas with increased human health risks by the methodology described above. The results of project are presented as the practical application of proposed limit values in the methodology of selected risks in fluvial zones. The Fluvisols are soil group with specific soil properties and soil vulnerability by contamination (the sources of soil contamination) developed on fluvial sediments. The floods are the most serious way of soil contamination and soil properties show a high heterogeneity and varia‐ bility. The heterogeneity is influenced by nature water stream dynamic (the gradient of erosion-deposition properties) with increased influence of neolitisation, it means acceleration of erosion-accumulation processes as the result of vegetation cover change and husbandry development in the landscape. The Fluvisols belong to fertile soils that has been used in agriculture historically. The husbandry in contaminated fluvial zones could cause increased risk and our study defines the risks on the most important fluvial zones in the Czech Republic.
