Meso- and macrofauna of the soil as the bio-indicators of the meadow soil polluted by heavy metals

Heavy metals are one of the most durable and toxic contamination of the soil environment. The content of heavy metals in the soil depends on environmental conditions and anthropogenic pollutions. Due to the intensification of the antropopressure their content increases constantly. It is widely known, that apart from some oligo-elements indispensable for life (Cu, Zn and Mn), most of the metals are potentially toxic for living organisms. Toxicity depends on their concentrations, chemical forms and the species of the particular organism. The main reason for the contamination of the soils by heavy metals is the fall of atmospheric dusts emitted by non-steel mil, transport and coal burning. As a result of consuming of fuels, rubbing of tyres and other vehicles parts Cd, Zn and Pb get into environment. The danger of soils contaminations related to the use of motor vehicles depends mainly on traffic intensity, distance from the roads as well as lay and use of the land.Due to the intensification of anthropopressure related to communication, the contamination of the soil by heavy metals has increased. Heavy metals are not particularly mobile and remain in the soil for years. However, it has to be emphasized that bioavailability of potentially toxic elements depends on pH as well. pH value strongly affect the disposition of micro- and macro elements in soil profile, what is particularly visible in case of acidic soils. The growth of acidity of the soils causes, among others, the growth of mobility of above mentioned metals and consequently their circulation in the ecosystem.