Ryzhenko N. Scientific principles of phytotoxicological assessment of metals hazard (Cd, Pb, Co, Cu, Ni, Zn) in ecosystems

The study’s results of the features of the metals (Cd, Pb, Ni, Co, Cu, Zn) influence on phytocomponent in ecosystems are presented in the thesis. The methodology for assessing the risk of metals in the ecosystem through the development of a Phytoletal Dose (PhLD50) algorithm was expanded, which is the universal reliable index of phytotoxicity of metals and allows comparative evaluation of the toxicity of these pollutants. A scientific approach to ecological standardization has been developed, which is the basis for regulating the safe level of metals in the soil concerning the phytocomponent in the ecosystem by means of Phyto maximum allowable concentration. It has been established that the polarity of metal compounds allows predicting their hazard, in particular, phytotoxicity in the ecosystem. The phytotoxicological classification of the hazardous metals has been developed, which allows detecting their harmful effects on the phytocomponent in the polluted ecosystem. The features of the distribution of metals (Cd, Pb, Co, Cu, Zn, Ni) concentration in phytomass plant ecosystems of the forest-park zone in Kyiv are highlighted. It was found that the content of metals in phytomass of grassy species significantly exceeds their concentration in tree species. It is suggested to use the Tussilago farfara L. and the Acer platanoides L. as the indicator species of metal contamination.