Baseline Heavy metal pollution assessment in relation to sediment properties in the coastal sediments of the southern Caspian Sea Kazem Darvish Bastami a,⇑ , Mahmoud Reza Neyestani b , Farzaneh Shemirani c , Farzaneh Soltani d , Sarah Haghparast e , Atefeh Akbari f a Iranian National Institute for Oceanography and Atmospheric Science (INIOAS), No. 3, Etemadzadeh St., Fatemi Ave., 1411813389 Tehran, Iran b Department of Chemistry, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran c Department of Analytical Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran d Young Researchers and Elites Club, North Tehran Branch, Islamic Azad University, Tehran, Iran e Department of Fisheries, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Km 9 Darya Boulevard, P.O. Box, 578, Sari, Iran f Yazd University, Natural Resources and Desert Studies Faculty, Yazd, Iran article info Article history: Available online xxxx Keywords: Heavy metals Major elements Surface sediment Caspian Sea abstract This study aimed to evaluate major elements and heavy metal concentrations of Arsenic (As), Copper (Cu), Chromium (Cr), Cobalt (Co), Vanadium (V), Nickel (Ni), lead (Pb) and Zinc (Zn) in surface sediments of the southern Caspian Sea. Metal contents in the sediment were observed in the order of: V > Cr > Zn > Ni > Co > Cu > Pb > As. Correlations between elements showed that sediment TOM, grain size and chemical composition are the main factors that influence the distribution of heavy metals. According to the pollution load index (PLI), sediments from some sampling sites were polluted. Concentrations of Ni, As, Cr and Cu were higher than sediment quality guidelines at some sampling sites, implying potential adverse impacts of these metals. Ó 2014 Elsevier Ltd. All rights reserved. Heavy metal pollution in marine ecosystems is a serious con- cern due to the toxic and long lasting effects (Zhan et al., 2010; Gao and Chen, 2012). Heavy metals in coastal sediment originate from both natural (physical and chemical weathering of parent rocks) and anthropogenic sources (Callender, 2005). Wastewater discharge, urban effluent and fertilizer application constitute the major anthropogenic inputs. Heavy metals are discharged into aquatic systems during trans- port, and distributed between the aqueous phase and sediment. Because of adsorption, hydrolysis and co-precipitation of metal ions, a large quantity of free metal ions are deposited in the sedi- ment while only a small portion of ions remain dissolved in the water column. Therefore, sediments in aquatic environments can either retain metals or release them to the water column by various remobilization processes. Sediment parameters (mineralogy, tex- ture), metal characteristics, pH, organic matter and oxidation– reduction potential are important parameters controlling the accu- mulation and the availability of heavy metals in the sediment (Hakanson 1980; Wright and Mason 1999; Tam and Wong 2000; Buccolieri et al., 2006; ElNemr et al., 2007; Bastami et al., 2012). Therefore, sediments are considered sources of heavy metals in marine environments and play a key role in transmission and depo- sition of metals. Generally, normal metal concentrations found in sediments are not detrimental to inhabiting organisms. For normal metabolism, live organisms essentially require some metals, such as zinc. How- ever, these metals can have toxic effects above a critical threshold. The Caspian Sea, which accounts for 40–44% of the total lacus- trine waters of the world, is denoted as a sea or lake. Because of high biodiversity in the Caspian Sea and its coastal zone, it is one of the most valuable ecosystems on earth. Because this region has been isolated from other bodies of water for a long time, a high level of endemism is remarkably evident in its fauna. The existence of shallow areas, several deep depressions and a wide range of salinities, varying from 0.1‰ to 13‰, provide different ecological niches, giving rise to high species diversity. The main goal of this study is to investigate heavy metals distri- butions in different compositions of surficial sediments from the southern Caspian Sea, and to discover relationships between the distributions and sediment characteristics. Sediment samples from twelve different sites were collected in autumn for heavy metal analysis using a Van-Veen grab sampler (November) 2013 (Fig. 1). Then, samples were packed and carried to the laboratory in iced-boxes and stored at 4 °C until analysis. http://dx.doi.org/10.1016/j.marpolbul.2014.12.035 0025-326X/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +98 9124450867. E-mail addresses: darvish_60@yahoo.com, darvish.bastami@inio.ac.ir (K.D. Bastami). Marine Pollution Bulletin xxx (2015) xxx–xxx Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Please cite this article in press as: Bastami, K.D., et al. Heavy metal pollution assessment in relation to sediment properties in the coastal sediments of the southern Caspian Sea. Mar. Pollut. Bull. (2015), http://dx.doi.org/10.1016/j.marpolbul.2014.12.035