Pb heavy metal monitoring using biological indicators, Prosopis juliflora, Eucalyptus microtheca and Ziziphus spina-christi in Ahvaz city (Iran)

Lead is one of the toxic and dangerous elements of the environment and has no biological role inthe body of living organisms. Three plant speciesProsopis juliflora,Eucalyptus microtheca, andZiziphus spina-christiwere considered as investigated plants in Ahvaz city of Iran.The highestamount of lead in the unwashed leaf samples of Algaroba trees at the low traffic station was72.56±0.01 mg/kg. The lowest amount of lead in leaf samples related to washed leaves of Lotustrees in low traffic station was 60.13±0.25 mg/kg. The pattern of lead accumulation in the washedand unwashed leaves of the studied trees in high traffic and low traffic areas was obtained asAlgaroba>Eucalyptus>Lotusand in the vicinity of the gas station as Eucalyptus>Lotus>Algaroba.The highest and lowest concentrations of lead in the soil were obtained 40.4 mg/kg and 18.33mg/kg, respectively. The results of this study on the accumulation of lead in all species and stationsshowed that the accumulation of lead was more than the WHO limit of 2 mg/kg. The BCF of theleaves of theProsopis juliflora,Eucalyptus microtheca, andZiziphus spina-christiin Ahvaz citywas higher than 1, so it can be concluded that these trees have the ability to accumulate lead intheir leaves, and they can be classified as hyperaccumulator plants.