Iranian Journal of

Background and Objective: Environmental pollution emitted from industrial areas while enter the food chain can cause serious adverse health effects. Therefore, this study was conducted to use Ziziphus spina-christi and Prosopis cineraria leaves as bio-indicators of environmental pollution emitted from the complex of Steel Company.
Materials and Methods: In this descriptive study, a total of 90 surface soil samples and also 90 leave samples were collected. After acid digestion of samples, the heavy metal contents were measured using atomic absorption spectrophotometer. Also, the Bioconcentration Factor (BCF) of metals were computed. All statistical analyses were performed using SPSS statistical package.
Results: The highest content of the metals (mg/kg) with an average of 2180.3 ± 202.3 and 2237.9 ± 315.1 for Fe, 76.6 ± 9.6 and 114.3 ± 4.5 for Pb and 69.2 ± 16.8 and 107.2 ± 6.8 for Cd were found to be in Z. spina-christi and P. cineraria unwashed leaves respectively. Also, the BCF of all studied metals were higher than 1.
Conclusion: Based on the values of BCF, it can be concluded that Z. spina-christi and P. cineraria can be considered as a suitable species for phytoextraction of heavy metals in the most polluted regions including industrial and urban areas.
 

Background and Objective: Air quality and distribution of trace elements in the Tehran metropolis were evaluated using transplants of the epiphytic lichen Ramalina sinensis.
Materials and Methods: Thalli of R. sinensis were collected from a non-contaminated area and transplanted in the six urban sites of Tehran for six months. After the end of the exposure period, the content of twelve elements in lichen was determined by ICP-MS method and the obtained data were evalusted using statistical analysis and various indicators.
Results: Based on the results, the order of mean concentration of the trace elements in the R. sinensis lichen samples was determined as: Ca > K > Fe > Mg > Na > Mn > Zn > Pb > Cr > Cu > Ni > Co and the highest amount of bioaccumulation was found for the essential elements. For sevelar elements, significant differences were observed in various sampling sites. Based on the pollution load indexes (PLIs), two sites at Sharif university and Setad Bohran were more polluted than other areas. Exposed-to-control (EC) ratio values for Pb, Zn, Cr, Fe, Mn, Ni, Mg, and Co were also found in the range of 1.25-1.75. Based on the relative accumulation factor (RAF), the accumulation preference of elements by R. sinensis lichen was observed as Na > Cr > Cu > Fe > Mg > Ni > Zn > Mn > Co > Pb > Ca > K, respectively, which represents the significant ability of this species in the accumulation of elements such as Na, Cr, Cu and Fe. PCA and EF analysis indicated that trace elements adsorbed by lichen were mainly sourced from vehicle transportation.
Conclusion: This study demonstrates the application and importance of R. sinensis lichen in biomonitoring of air pollutants elements in urban areas. This approach can justify the suitability, accuracy and cost-effectiveness of lichen compared to other biomonitors for air pollutants and more importantly highlights its capability to the determination of wide levels of air pollution in large scales.