Assessment of Heavy Metal Bioaccumulation in Some Tissues of Leuciscus Cephalus from Karasu River, Erzurum-Turkey

Research Article

Austin J Environ Toxicol. 2015;1(1): 1004.

Assessment of Heavy Metal Bioaccumulation in Some Tissues of Leuciscus Cephalus from Karasu River, Erzurum-Turkey

Kalkan H1, Sisman T1* and Kiliç D1

1Department of biology, University of Maribor, Slovenia

2Agricultural Institute of Slovenia, Slovenia

*Corresponding author: Sisman T, Department of Biology, Science Faculty, Atatürk University, 25240 Erzurum, Turkey

Received: September 29, 2014; Accepted: February 16, 2015; Published: February 18, 2015


Karasu River, the only river in the Erzurum plain, is the source of Euphrates River (Eastern Anatolia of Turkey). It is considered that artificial fertilizers, pesticides, municipal sewage, industrial and factory wastes are polluted the Karasu River. The pollution in the river also threatens the Euphrates basin. Fish live in direct contact with their immediate external environment. Therefore, fish are frequently used to determinate the aquatic pollution. In this study, we aim to determine concentrations of metals such as Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg and Pb on liver, muscle and gill tissues of Leuciscus cephalus (chub) which was obtained from the selected two points (Dumlu and Askale) on Karasu River. The heavy metals were measured by ICP-MS (Inductively Coupled Plasma-Mass Spectrometer). The concentrations of heavy metals in tissue of fish from the Askale site were significantly higher than those from the Dumlu site. High levels of metals were found in the gills in fish from Askale site. These results show that the concentrations are below the limits for fish proposed by Turkish Food Codex, FAO/WHO and EC, and safe within the limits for human consumption in the edible parts of fish species in the region.

Keywords: Heavy metals; Karasu River; Pollution; Leuciscus cephalus; Health risk


There are countless pollutants in the surface waters and sediment that are compromising the survival of the organisms, altering their physiologies or giving rise to carcinogenesis. Consequences caused by these pollutants may remain recessive for several generations or may exhibit major effects in the population. Pollution in the aquatic environment causes multiple damages in the organisms, at the level of population and ecosystem, as in organ function, reproductive performances and biological diversity [1]. In aquatic environments, particularly industrial and domestic wastes discharged without being treated, are the source of heavy metals [2]. The increasing of heavy metal contamination in aquatic systems and decreasing sediment quality may cause toxicity in freshwater ecosystems [3]. The toxicity of metals depends on the metal type and concentration, the period of exposure and other factors. Also, metals join in the food chain and are responsible for adverse effects and death in the aquatic organisms [4]. In addition to this contamination causing an adverse effect on aquatic biota, the metallic contaminants can be ingested by humans through consumption of the seafood products [5].

In some areas of the world, aquatic organisms, especially fish, are the most important sources of protein in the human diet. Fish are widely being used for evaluating the quality of the aquatic environment and as bioindicators of environmental pollution [6,7]. Fish have also been used extensively to study the physiological behavior of heavy metals in body organs [8]. The concentration of metals is a function of species, and metals accumulate more in some fish tissues than in others [9]. Different tissues of fish species have different bioaccumulation capacities [10]. The sampling location and season, as well as diet preferences and fish size may influence the level of bioaccumulation in the same fish species [11]. Liver and gills, as metabolically active organs, are target organs for metal accumulation [12], while the accumulation in muscle tissue is lower [13]. The concentrations of metals in the organs of fish are governed primarily by the level of pollution in the water and food and so are indicative of the level of pollution in the environment [14]. Furthermore, ecological needs, gender, size and seasonal changes can affect metal accumulation in different tissues of fish [15,16].

The Karasu River, which is the only river in Erzurum plain, is the source of the famous river Euphrates. The river is also an important tributary of the Tigris River and has been polluted substantially with sewage water and effluent wastes of slaughterhouses, fat, sugar and cement factories. Hence, mass fish deaths have been occurred twice in the past 10 years [17]. The pollution in the Karasu River also threatens the Euphrates basin. Leuciscus cephalus (chub) is fish species belonging to the Cyprinidae family. Although the fish can be found in the upper zones of the Tigris and Euphrates rivers, they live mainly in the upper regions of Karasu River [18]. In this study, chub is used as a bioindicator for monitoring the aquatic environment because the fish is abundant at Karasu River.

Over the last decades, there has been interest in determining metal contents in fresh water environment, and attention was drawn to the measurement of pollution in public food supply especially fish. Several reliable analytical methods were available for monitoring metal levels in fresh water and marine food samples, but Inductively Coupled Plasma Mass Spectrometer (ICP-MS), being the most sophisticated and reliable technique was widely used for determination and quantification of trace metals in food samples [19]. The present study was undertaken to determine the concentrations of selected metals (Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Hg and Pb) in the surface water and liver, muscle, and gill tissues of Leuciscus cephalus (chub) from the selected two sites (Dumlu and Askale) on Karasu River.

Materials and Methods

The Karasu River is located in the Eastern Anatolia region of Turkey (Erzurum) and drains an area of approximately 1642 km2 and joins the Euphrates River. At the upper section of the river, various industrial activities, like textile dyeing, cement and sugar factories release their waste into the river. Due to the extended domestic and industrial activities, various pollutants reach the river at different points and potentially change the water quality. Two sampling sites were selected in the Karasu River, with different levels of chemical impact (Figure 1). Firstly, an impacted site was Askale site located approximately 80 km further downstream which is a heavily contaminated tributary collecting industrial effluent. Dumlu site relatively uncontaminated location was used as control, another tributary of the Karasu River. All located inside the city provinces of Erzurum. Askale site at near the Askale district shows strong anthropogenic influence, receiving domestic, agricultural and industrial effluents. The site is 58-km outside the Erzurum city.

The coordinates of sampling Dumlu site are 40o 01' 52K, 41° 18' 49D and that of sampling Askale site are 38o 22' 33K, 36o 58' 26D (Figure 1).