Metals Phytotoxicity Assessment and Classification

In this paper, the influence of trace metals(Cd, Pb, Cu, Co, Ni, Zn) on plants of spring barley (Hordeum vulgare L.) was investigated in polluted sod podzolic sandy loam on layered glacial sands and calcareous deep chernozem on loamy loess soils. We propose to estimate the phytotoxicity with help of phytotoxicological classification. The phytotoxicological classification of trace metals gives the possibility to assess their hazard for plants. On the base of indicators such as: plant up-taking index (UI), phytoletal dose (PhLD50), Dipole moment (µ), Phyto Maximum Allowable Concentration (PMAC) a phytotoxicological classification of hazardous trace metals was suggested. The four classes of danger in phytotoxicological classification of hazardous trace metals were offered. According to phytotoxicological classification, Cd, Co, Ni belong to the first class of hazard, Cu – to second class of hazard, Zn – to third class of hazard, Pb – to fourth class of hazard. Phytotoxicological classification of hazardous trace metals gives the possibility to comprehensively estimate the danger of trace metals for plants as a biological object that plays a very important role in the life of ecosystem. This approach may be applied for another trace metals risk assessment for other plants.