title: Assessment of bed sediment metal contamination in the Shadegan and Hawr Al Azim wetlands, Iran.
abstract: The Shadegan and Hawr Al Azim wetlands are important natural resources in southwestern Iran, yet relatively little work has been done to assess ecosystem health of the wetlands. Bed sediment from both wetlands was sampled in individual months between October, 2011 and December, 2012 and analyzed for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES). The metals data were evaluated using a combination of sediment quality guidelines from the Ontario Ministry of Energy and Environment (MOEE, Canada), enrichment factors (EFs), and a geo-accumulation index (Igeo) approach. The sediments exceeded MOEE Lowest Effect Levels (LELs) consistently for Cr and Cu and a small proportion of samples (5%) for Hg. Levels of As, Cd, Fe, Pb, and Zn did not exceed LELs and none of the samples exceeded the Severe Effect Levels (SELs). In addition to the sediment guidelines, both the EF and Igeo calculations suggested levels of Mn and Fe were severely enriched, while the EF indicated Cd was slightly enriched. Metal levels in the Shadegan wetland exhibited both spatial and seasonal trends. Metal levels were greater near input areas from agricultural, urban, and industrial discharges and runoff as compared to the more remote and quiescent central part of the wetland. Except for Fe, the metal levels were greater in the wet season as compared to the dry season, perhaps due to greater stormwater runoff and sediment loads. This study provides baseline data which can be used to support development of appropriate contaminant source management strategies to help ensure conservation of these valuable wetland resources.
authors.affiliation: Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. hanasirian@yahoo.com.
authors.forename: Hassan
authors.initials: H
authors.lastname: Nasirian
authors.affiliation: National Institute of Education, Nanyang Technological University, Singapore, Singapore.
authors.forename: K N
authors.initials: KN
authors.lastname: Irvine
authors.affiliation: Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sayyed Mohammad Taghi
authors.initials: SM
authors.lastname: Sadeghi
authors.affiliation: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.|Center for Solid Waste Research, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Mahvi
authors.affiliation: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Nazmara
mesh_terms: D000383:Agriculture; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D007492:Iran; D008628:Mercury / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Assessment; Bed sediment; Contamination; Hawr Al Azim; Metal; Shadegan; Wetland