Toxic Contamination
Content
Soil Contamination

Risk elements content in agricultural soils of Slovakia

        Year 1997 was the first year of the second stage of the state soil monitoring system. Soil samples were gathered from all sites of the basic monitoring network that means 312 monitoring sites on agricultural land and from 21 key monitoring sites. Currently the analyses of the gathered samples are being carried out. Therefore, the listed data regarding the amount of contaminants are related to soil contamination in 1996.

The highest allowed concentration of some hazardous substances in soils (in mg per kg of dry matter)
 
Hazardous substance 
A
A1
B
C
Metals 
        
As
  29
     5.0
      30
     50
Ba
500
  x
1 000
2 000
Be
   3
  x
     20
    30
Cd
      0.8
     0.3
      5
    20
Co
  20
 x
     50
  300
Cr
130
  10.0
  250
   800
Cu
 36
20
  100
   500
Hg
      0.3
x
      2
    10
Mo
   1
x
    40
   200
Ni
 35
   10.0
  100
   500
Pb
 85
  30.0
  150
   600
Se
     0.8
 x
     5
    20
Sn
 20
 x
    50
   300
V
120
 x
   200
   500
Zn
140
   40.0
  500
3 000
Inorganic substances 
  
 x
    
F(total)
  5002)
 x
1 000
2 000
S(sulphidic)
  2
 x
    20
   200
Br(total)
 20
 x
    50
   300
Notes:                                                                         Source: VÚPÚ

  1. values valid for the given standard soil (25% of loam fraction and 10 % of organic material out in the content of the total content)
  2. the simultaneous analysis of the fluorine water soluble forms must be carried out and the threshold value of the possible toxicity is the value greater than 5 mg per kg.
A - reference value; soil is not contaminated if the substance concentration is less than this reference value. If the concentration is equal or greater than this reference value, the substance concentration is higher than the background values valid for the observed site or the values are higher than the sensitivity threshold of the relevant analytical analysis
A1 - reference value related to value A and valid for the assessment of the hazardous substance extraction with 2M HNO3
B - indicative value means that the soil contamination was analytically proven. The further study and the contaminated site control is required if the cause, area and contamination can have a negative impact on human health or on other components of the environment
C - sanitary indicative value ; if the substance concentration value is equal or greater than this sanitary indicative value, the immediate analytical mapping of the pollution extent in the referred site is required followed by the proposal for decontamination. If values are within the range of B or C similar procedure should be followed.

 

Soil contamination categories in the SR - statistics

                                                                                                                                        Source: VÚPÚ
 

Soil contamination map of the SR
Cadmium content (extraction with 2M HNO3) in the upper soil horizon in the SR
Lead content (extraction with 2M HNO3) in the upper soil horizon in the SR

         On the Slovak territory the relations between occurrence of some risk trace elements and the soil attributes are rather complicated, especially in mountain ranges proximity, due to the endogenous geochemical anomalies. However, the results of monitoring indicate that the soils in the SR are contaminated by hazardous substances at relatively low level. Note that the greatest part of the category A, A1 (category with the largest area) is represented by forest land. Soils with significant contamination represent only 1.4% of the category B and 0.4% of the category C.

        The analyses of mobile and potential mobile forms of risk trace elements are very important in relation to the risk assessment of their possible penetration entry into the food chain and biological circulation with negative impacts on mankind and the environment. The order of trace elements share bound by plants in comparison to total accessible content is as follows: Cd > Zn > Ni > Pb > Cu > Cr. Due to this fact, Cd and also Zn and Ni are the trace elements of extra importance. Zn and Cu are classified at mainly lower levels as micronutrients rather than contaminants. The mobility of Cr is very low.
 

Polycyclic aromatic hydrocarbons (PAHS) substances content in agricultural soils of Slovakia
Aims, principles, structure and methods of Partial Monitoring System SOIL
Problem of mobile and potential mobile forms of risk trace elements in soils and their importance in soil monitoring