The content of Cd in medicinal plants growing in the floodplains of the rivers Irtysh and Ob

To determine the safety of using medicinal plants for therapeutic purposes we investigated the levels of heavy metals (namely, cadmium Cd) in medicinal plants growing in the floodplains of the Irtysh (Semey, Ozerki) and the Ob (Berdsk). In the studies conducted in 2013-2016 field and laborato-ry methods were involved. The study describes the material on the content of cadmium in medicinal plants depending on species, morphological and systematic characteristics of plants. As it was shown by the results of research cadmium concen-tration varied from 0.05 to 0.39 mg/kg, in average 18 mg/kg. Cadmium content in morphological or-gans in general populations of medicinal plants de-creases in the following order: Cd - the roots (0.24) > sheets (0.17) > flowers (0.13). The studied collec-tion of medicinal plants in floodplains of the Irtysh and the Ob on the content of cadmium (mg/kg) were arranged in the following descending order: the Nettle Family - (0.26) > the Family Polygonaceae - (0.25) > Family Umbrella - (0.24) > Valerian Family - (0.23) > the Family Asteraceae - (0.19) = the Family of Legumes - (0.19) = Rosaceae Family - (0.19) = Plantain Family - (0.19) > the Family Labiatae (0.16). The average value of Cd was 0.23 mg/kg. All investigated sections of the flood-plain were characterized by minimal accumulation of the element in the riparian zone, the Central area was divided into zones and clear patterns in the distribution of the item was revealed: Berdsk: the area was divided into > central > riparian; Semey: central > area was divided into ≥ riparian; Ozerki: central ≥ area was divided into ≥ riparian. Accord-ing to the findings, the excess of maximum permis-sible concentration according to average values for Cd 0.18 mg/kg was not detected. But in some types of herbs, namely, tansy (Cd=0.29 mg/kg), Melilotus officinalis (Cd=0.27 mg/kg) the excess of maximum permissible values, regardless of the plot area of the floodplain was observed. We can conclude that these medicinal plants are heavy metals concentra-tors and cannot be recommended for using. Also the species with minimum concentration of ele-ments - the dandelion and red clover (Cd=0.12 mg/kg) were identified. These types of medicinal plants should be encouraged for gathering, prepa-ration and using, as using of above mentioned me-dicinal plants for medical purposes does not pose any risk to health.