Background: Sediments are integral part of wetlands providing a valuable key to recognize heavy metal fluctuations in the past. Materials and Methods: The surface sediment samples were taken from thirteen sites, then prepared and digested with percholoric acid and nitric acid at 1:4 ratio, followed by flame atomic absorption spectrophotometry analysis. Results: The average of total metal concentration in 13 sites were found to be 9.182, 9.514, 45.351 and 43.456 µg g -1 for Pb, Zn, Cu and Ni, respectively. Also, comparison of sediment quality indices, including contamination factor (Cf), contamination degree (Cd), and modified contamination degree (mCd)) showed that Cu contamination was significantly different from the other heavy metals, while Ni contamination was average, and Pb and Zn contaminations were low. Discussion and Conclusions: This research confirms that the Mighan wetland is polluted with heavy metals and their excessive accumulation in sediments.
