Global Journal of Human-Social Science, B: Geography, Environmental Science and Disaster Management, Volume 22 Issue 3

A grouping of the samples in the following subgroups has been obtained according to their content in the following minority elements: - Samples from 0 to 50 individuals present similar contents of Be, Cr, Cu, Cr and S. - Samples from 51 to 150 individuals present similar contents of As, B, Co and V. - Samples from > 150 individuals present similar contents of Be, Cr, Cu, V, As and B. In view of these results, a second statistical study of the discriminant was carried out, in order to study in more detail the samples that presented up to 50 individuals in an area of 1m2 (Figure 2). The samples are grouped into the following subgroups. - Soil samples without plants: Similar contents of Cr, B and Li. - Soil samples with less than 10 individuals: Similar contents of Be, V, P and S. - Soil samples with 10 to 50 individuals: Similar contents of Cr, B, Li, Be, P and V. According to the bioaccumulation capacity of Ailanthus altissima , B, Cu, Sn and Sr are the elements that can be considered bioaccumulated by the leaves of A. altissima since its bioconcentration factor (FBC) is higher than the unit (FBC ≥1). In addition to the aforementioned elements, other compounds such as Cu and Ni can be considered to have a certain cumulative character, since their bioconcentration factor is ≥0.5 (Table 2). Table 2: Bioconcentration factor values (FBC). Element Average concentration in leaves (ppm) Average concentration in soil (ppm) FBC Sn 41 8 5,06 B 174 148 1,18 Sr 108 92 1,17 Cu 22 24 0,92 Ni 6 12 0,51 Mn 102 213 0,48 Zn 31 70 0,45 Cr 4 11 0,34 Ce 4 16 0,25 Sc 1 3 0,25 Zr 7 39 0,18 As 1 8 0,12 Ba 40 375 0,11 V 3 30 0,11 Ga 1 14 0,09 Rb 10 127 0,08 Li 3 51 0,07 Pb 2 39 0,06 They have differentiated: - Elements not accumulated in the leaves: They have bioconcentration factor less than 0.5 (FBC ≤ 0.5). Among these elements are As, Ba, Ce, Cr, Ga, Li, Mn, Pb, Rb, Sc, Zn and Zr. - Possible bioaccumulated elements: These are those that present a bioconcentration factor (FBC≥ 0.5). Cu and Ni. - Bioaccumulated elements: Those whose bioconcentration factor is equal to or greater than the unit (FBC ≥ 1), B and Sr. - Potentially accumulated elements: Those elements whose concentration in the leaves is significantly higher than in soils. In research, the only element with this characteristic is the Sn (FBC >5). V. D ISCUSION The processes of industrialization, urban development, change in land uses and other anthropic actions contribute to the increase in the concentration of chemical substances (heavy metals or trace elements) that can be harmful to plant organisms. The toxicity of metals in plants depends on the tolerance of each species tolerance, the chemical element in question and/or the physicochemical characteristics of the soil. Thus, certain metals are considered essential for the growth and development of plant organisms, such as Cu and Zn that activate enzymatic reactions and participate in the Redox reactions of plants. Or the Cu that acts in the photosynthetic process (Mahmood & Islam, 2006; Chatterjee et al. 2006). Zn is essential for ribosomes. Co Volume XXII Issue III Version I 4 ( ) Global Journal of Human Social Science - Year 2022 © 2022 Global Journals B Ailanthus Altissima (Mill.) Swingle, Bioacumulated Specie of Contaminated Soils Fig. 2: Result of the statistical analysis of the discriminant of soils with less than 50 individuals based on their content in minority elements.