Assessment of Selected Heavy Metals and Enzymes in Soil Within the Range of Impact of Illegal Dumping Sites

Defining the physicochemical and biological parameters in soil under illegally dumping sites provides information on the real threat and the direction of changes in the soil environment. The paper demonstrates the result of changes in the properties in soil as a result of the operation of illegal dumping sites. Soil was sampled from the research points located on the outskirts of the city of Bydgoszcz (Poland) from the site not affected by illegal dumping sites (control C), within the dumping sites, having removed the waste layer (W), and 10 m away from the dumping sites (W 10). In the soil the content of phosphorus, potassium, magnesium and sulphur, total content of copper, zinc, lead and nickel as well as the activity of enzymes were assayed. The content of Pb, Zn, Cu and Ni in the soil samples qualifies the soils as representing the soil category with natural content. The greatest activity of all the enzymes analysed was identified in the soil sampled from the control point affected by waste, whereas the highest content of macroelements was reported in the soil from the dumping sites (W 10). A high variation in the enzymes under study in soils confirms a high value of the coefficient of variation (CV > 36%). The analysis of correlation confirmed the relationship between the content of organic carbon compounds and the content of zinc, lead, nickel. The soils show a slight value of the coefficient of contamination for heavy metals (CF < 1). The contamination degree (Cdeg) ranged from 1.993 to 5.116, which points to a low level of soil contamination with Zn, Cu, Pb and Ni.