Contents lists available at ScienceDirect Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv Measurement and prediction of bioconcentration factors of organophosphate flame retardants in common carp (Cyprinus carpio) Tadiyose Girma Bekele a,b , Hongxia Zhao a, ⁎ , Yan Wang a , Jingqiu Jiang a , Feng Tan a a Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China b Department of Natural Resource Management, Arba Minch University, P.O. Box 21, Arba Minch, Ethiopia ARTICLE INFO Keywords: Organophosphate flame retardants Common carp Bioconcentration Tissue distribution QSAR ABSTRACT The increase in the production and usage plus the toxicity nature of organophosphate flame retardants (OPFRs) has become a concern. However, limited information is available about the bioaccumulation potential of OPFRs in fish. In this study, we determined the 96 h LC 50 s , and evaluated the bioaccumulation potential of six most frequently reported OPFRs in gill, kidney, liver, and muscle tissues of common carp (Cyprinus carpio) for 48 d, and a quantitative structure-activity relationship (QSAR) model was developed to predict bioconcentration factors (BCFs) for the remaining 16 OPFRs. The BCFs and half-lives (t 1/2 ) in the tissues ranged from 6.54 (Tris (2- chloroisopropyl) phosphate, (TCPP)) to 528.15 (Tris (2-ethylhexyl) phosphate (TEHP)), and 2.25–5.78 days, respectively. The tissue-specific concentration and BCFs values followed the order of liver > kidney ≥ intestine > > muscle. The proposed QSAR model with a high cross-validated value (Q 2 (cum) ) of 0.930 and a correlation coefficient of 0.94 was obtained and was able to predict log BCF from parameters related to molar volume and isotropic average static field polarizability. The results show that the model has a high level of accuracy, making the proposed approach a suitable method for predicting the log BCF. 1. Introduction The restriction of polybrominated diphenyl ethers (PBDEs) as a flame retardants because of their confirmed persistence, long-range atmospheric transport, bioaccumulation and potential adverse effects on wildlife and humans (Abbasi et al., 2016; Stasinska et al., 2014) has led to an increase in the production and use of organophosphate flame retardants(OPFRs) and they accounted for 30% of total global flame retardants in 2013 (Wang et al., 2015). OPFRs are widely used as alternative flame retardants, plasticizer and anti-foaming agents in different industrial and consumer products, such as paints, decoration materials, textile, polyvinyl chloride (PVC) plastics, polyurethane foams (PUFs), construction, electronics, vehicle, furniture, and petroleum industries (Marklund et al., 2003; Van der Veen and de Boer, 2012; Wang et al., 2017; Wei et al., 2015). Like other additives, OPFRs are not chemically bound to the substrate material, thus, they are easily released to different environmental compartments, especially to the aquatic environment via diffusion, and leaching over their lifetime, including production, usage, disposal and recycling processes (Wei et al., 2015; Wolschke et al., 2015). As a result, OPFRs have been reported in surface water, air, soil, and sediment (Cristale et al., 2013; Li et al., 2017; Mihajlović and Fries, 2012; Zha and Li, 2018). More recently, OPFRs were reported in human breast milk, hair, serum, and urine (He et al., 2018; Kucharska et al., 2015; Sundkvist et al., 2010), and they become great concern to our environment and health. The increase in the production and usage plus the toxicity nature of OPFRs has elevated the concern. Among OPFRs,tri-n-butyl phosphate (TBP), tris(2- chloroisopropyl) phosphate (TCPP), tri(1,3-dichloro-2- propyl) phosphate (TDCP), triphenyl phosphate (TPP), tris（2-ethyl- hexyl） phosphate (TEHP), and tricresyl phosphate (TCP) have been frequently reported as they pose different toxic effects in fish, human and other aquatic organisms. Carcinogenicity, dermatitis, skin irritation and neurotoxicity are among the primary human health effects (Van der Veen and de Boer, 2012; WHO, 1991a, 1991b, 1998, 2000). Moreover, Lassen and Lokke (1999) showed that TPP is acutely toxic to fish, shrimp, and Daphnia. Apart from their direct effect OPFRs induces transgenerational effects, for example, after 240 day exposure of zeb- rafish to environmentally relevant concentrations of TDCP, Yu et al. (2017) reported the inhibition of growth on the parent generation and larvae of first generation, which were not directly exposed to TDCP, but rather impacted due to the accumulated TDCP. https://doi.org/10.1016/j.ecoenv.2018.09.089 Received 4 July 2018; Received in revised form 6 September 2018; Accepted 21 September 2018 ⁎ Corresponding author. E-mail address: hxzhao@dlut.edu.cn (H. Zhao). Ecotoxicology and Environmental Safety 166 (2018) 270–276 0147-6513/ © 2018 Elsevier Inc. All rights reserved. T