Hyperaccumulators of heavy metals of industrial areas of Islamabad and Rawalpindi

Contamination of heavy metals is one of the major threats to water and soil as well as human health. phytoremediation has been used to remediate metal-contaminated sites. this study evaluated the potential of 23 plant species growing on contaminated sites in industrial areas of the islamabad and rawalpindi. plant root,shoot and the soil samples were collected and analyzed for selected metal concentration values. to evaluate the potential of plant species for phytoremediation: bioconcentration factor (bcf),biological accumulation coefficient (bac) and biological transfer coefficient (bcf) were calculated. the concentration of pb in soils varied from 2-29 mg/kg,zn from 28.82-172.56 mg/ kg,cu from 8.88-306 mg/kg,respectively. the concentration of pb in plant shoots varied from 1.0 to 39 mg/kg,zn from 17.25 to 194.03 mg/kg,cu from 0.65 to 171.83 mg/kg. the concentration of pb in roots of plant varied 1-43 mg/kg,zn from 3.34-116.16 mg/kg,cu from 3.35- 416.89 mg/kg. brachiaria raptans and malvastrum coromandelianum were found most suitable for phytostabilization of sites contaminated with pb and cu (bcf= 18 and 9.12). considering the bac values,15 species for pb,two species for cu,five species for zn possessed the characteristics of hyperaccumulator,none of the plant species was found as hyperaccumulator; however plants with high bcf (metal concentration ratio of plant root to soil) and low btc (metal concentration ratio of plants shoots to roots) have the potential for phytostabilization and phytoextraction. the results of this study can be used for management and decontamination of soils with heavy metals using plant species having phytoremediation potential/characteristics.