Contents lists available at ScienceDirect Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv Environmental contaminants in fish species from a large dam reservoir and their potential risks to human health Memet Varol a, ⁎ , Muhammet Raşit Sünbül b a Malatya Turgut Özal University, Faculty of Fisheries, Malatya, Turkey b East Mediterranean Transitional Zone Agricultural Research of Institute, Kahramanmaraş, Turkey ARTICLE INFO Keywords: Environmental contaminants Wild fish Karakaya Dam Reservoir Human health risk assessment ABSTRACT The residue levels of antibiotics, metals and organochlorine pesticides (OCPs) were investigated in six fish species from the Karakaya Dam Reservoir, Turkey. Among monitored antibiotics, only enrofloxacin and oflox- acin were detected in muscle of fish species. Enrofloxacin levels in positive samples ranged from 0.0034 to 0.0073 mg/kg. It was detected in four fish species (trout barb, common carp, chub and Euphrates barbell), while ofloxacin was only found in common carp with the concentration of 0.0072 mg/kg. Both enrofloxacin and ofloxacin levels were below the maximum residue levels. No detectable residues of any OCPs were found in fish species. The highest toxic metal (As, Cd and Pb) content was detected in Euphrates barbell (0.103 mg/kg). Arsenic, Cd, Cr, Cu, Pb and Zn levels were well below the maximum permissible limits. The levels of antibiotics and metals found in fish species in the present study were generally lower than or comparable to those reported in other water bodies. According to estimated daily intake and hazard quotient values, antibiotics and metals detected in these wild fish species do not appear to pose a serious risk to public health. 1. Introduction In recent years, significant amounts of antibiotics have been used for treatment and prevention of humans and animal diseases. In addi- tion, some veterinary antibiotics have been used as growth promoting agents in animal production. However, antibiotic residues accumulated in animals could cause a potential risk to human consumers via food consumption. Moreover, the continuous application of antibiotics can promote development and transfer of antibiotic resistant bacteria in the environment. Therefore, the occurrence and potential environmental impact of antibiotic residues have increasingly received attention worldwide (Zhao et al., 2015; Kümmerer, 2009; Chen et al., 2015). Large amounts of antibiotics could be transported to aquatic environ- ments via municipial wastewater discharges and surface runoff from agricultural fields fertilized with animal manure (Xu et al., 2014; Giger et al., 2003). In recent years, aquaculture has also become an important source of antibiotic residues. Along with the rapid development of aquaculture farming, the use of antibiotics for therapeutic purposes and as prophylactic agents in fish farms is more and more increasing. Thus, their extensive use in fish farms can cause antibiotic pollution in the aquatic environment, and antibiotics in water may be bioaccumulated in aquatic organisms (Chen et al., 2015; Kim and Carlson, 2006; Xu et al., 2014; Li et al., 2012). Heavy metal pollution is an important problem in aquatic en- vironments due to their toxicological effects and persistence. Wastewaters from industrial and urban activities are main sources of metal contamination in the aquatic environment (Bosch et al., 2016). Metals such as Cu, Co, Fe and Zn are essential elements due to their important roles in biological systems, but their high concentrations can lead to toxic effects. Cd, As and Pb are non-essential elements and they can have harmful effects even at trace concentrations. It is known that heavy metals can bioaccumulate in the aquatic organisms and bio- magnify in the food chain to levels that can cause health risks to hu- mans who consume fish (Tuzen, 2009; Goyer et al., 2004). Organochlorine pesticides (OCPs) are a significant global concern because of their toxic effects on animals and humans, persistence and bioaccumulation in the food chain (Yohannes et al., 2014; Kalyoncu et al., 2009). These compounds had been widely used in agriculture and public health in past decades. Although the use of these pesticides has been banned in many developed countries, they are still used in some developing countries. OCPs entering aquatic environments bioconcen- trate and biomagnify in the food web, and finally reach humans by consumption of fish. These chemicals can cause developmental, re- productive and growth abnormalities, and carcinogenic, mutagenic, neurological and immunological adverse effects in humans and animals (Dang et al., 2016; Wang et al., 2015). https://doi.org/10.1016/j.ecoenv.2018.11.060 Received 12 September 2018; Received in revised form 5 November 2018; Accepted 15 November 2018 ⁎ Corresponding author. E-mail address: memet.varol@ozal.edu.tr (M. Varol). Ecotoxicology and Environmental Safety 169 (2019) 507–515 0147-6513/ © 2018 Elsevier Inc. All rights reserved. T