Evaluation of the bioaccumulation of heavy metals and 137Cs in succulent plants Echeveria elegans

In this work, the bioaccumulation of metals and 137Cs in the Echeveria elegans plant is evaluated. This is a semidesert plant, a highly adaptable and complex metabolism that is used extensively in urban gardens and green walls in urban centers. To determine the accumulation potential, the root accumulation factor (RAF) and shoot accumulation factor (SAF) were used, the transfer of metals from the root to the shoots was determined with the translocation factor (TF). Soil samples were enriched with 80, 120, 250, and 320 mg/kg of CsNO3 to simulate the retention of 137Cs. The quantitative analysis in the shoots and roots showed that the metals that present an RAF > 1 were Cu > Fe > Zn > Ni > Cr > Mn > Pb > Cs, the Pb and Cs presented similar values. Likewise, the metals that presented a SAF > 1 were Zn > Cu > Fe > Mn; SAF   Pb > Cs > Cr. The RAF and SAF obtained showed that E. elegans accumulates metals preferentially in the roots. Pb and Cs are the metals that bioaccumulate most efficiently in the plant. The study allowed us to conclude that E. elegans can bioaccumulate metals such as Zn, Ni, Cr, Pb, and Cs, which suggests that it has the potential and characteristics to be used as a biomonitor for contamination by metals and cesium.