risk assessment and environmental geochemistry of pb, cu and fe in surface sediments (case study: hashilan wetland, kermanshah, iran)

the total concentration and percentage of heavy metals content in the sediment of hashilan wetland, kermanshah province, was assessed in summer 2015. the total concentrations of cu, pb, and fe were around 18.57, 6.95 and 379.24 μg g-1, respectively. successive extractions of the samples showed a decreasing trend as follows: residual>organic matter>iron and manganese oxides>exchangeable parts. the comparison of the total metal concentrations and sqgs and noaa standards proposed high concentrations of pb and fe contents, while rac suggested that cu, pb, and fe had posed a low-moderate risk, low risk and no risk to the system, respectively. furthermore, the results showed that the most common sources of pb and fe were natural while sources of cu was anthropogenic. continuous monitoring of the wetlands, particularly water inputs are recommended.