INTRODUCTIONFish is usually located at the top of the food chainin the marine ecosystem. It accumulates contaminantsfrom water, food, bottom sediment, and suspendedparticles in the water column. Even though availableand accessible literature shows that heavy metalsaccumulated in the Black Sea commercial fish haveno detrimental effect on human health [1], this issueremains a matter of public concern. However, thepresent research confirmed the fact that Black Sea fish isunaffected by environmental situation and is safe to eat.A review conducted by Bat et al. showed someconcern about the increase of unregulated settlementsand anthropogenic activities along the marine coastalarea of the Black Sea [2]. The growing urbanizationand industrialization, as well as the fast developmentof agriculture, tourism, and fishery, increase theconcentration of heavy metals discharged by majorrivers into the coastal waters of the Black Sea. Theresulting increase in heavy metals adversely affects thecoastal ecosystem.The contaminants eventually accumulate inmarine biota, particularly in fish [3, 4]. Subsequently,metals pass on to people that consume contaminatedfish, thus threatening their health [5]. As a result,the environmental issues related to heavy metalcontamination of the Black Sea are relevant to allcountries along the Black Sea coast. After Romaniaand Bulgaria entered the European Union, the problemaffected the whole of Europe.The Marine Environment Policy of theMarine Strategy Framework Directive (MSFD)concerns the matters of monitoring chemicalelements in edible tissues of seafood and avoidingheavy metal transfer from sea biota to humanbody via food chain [6]. The MSFD targets theResearch Article DOI: http://doi.org/10.21603/2308-4057-2020-1-115-124Open Access Available online at http://jfrm.ru/en/Health risk assessment: heavy metals in fish fromthe southern Black SeaLevent Bat* , Ayşah Öztekin , Elif Arici , Fatih ŞahinSinop University, Sinop, Turkey* e-mail: leventbat@gmail.comReceived December 27, 2019; Accepted in revised form January 20, 2020; Published February 25, 2020Abstract:Introduction. The coastal contamination of the Black Sea has been an important issue for several decades. Heavy metals are the mostharmful contaminants which affect people health. The research objective of the present study was to determine the amounts of Cd,Hg, Pb, Cu, and Zn found in the whiting (M. merlangus L.) and the red mullet (M. barbatus L.). These Black Sea bottom fish specieshave the highest commercial value. The obtained data were used to assess the risk which the fish represents for human consumers.Study objects and methods. The elements were detected using an inductively coupled plasma mass spectrometer (ICP-MS).The amounts of the metals arranged in the following order: Zn > Cu > Pb > Hg > Cd.Results and discussion. The mean values of Cd, Hg, Pb, Cu, and Zn in the edible tissues were 0.013, 0.024, 0.07, 0.195, and 9.05 mg/kgwet wt. for whiting and 0.017, 0.036, 0.05, 0.29, and 6.4 mg/kg wet wt. for red mullet, respectively. These levels proved lower thanthe permitted values set by the Ministry of Agriculture, Forestry, and Fisheries of the UK (MAFF), Turkish Food Codex (TFC), andEU Commission Regulation. The target hazard quotient (THQ) for all the elements via consumption of whiting and red mullet werealso low.Conclusion. Hazard index (HI) was ˂ 1, which means that the fish caused no health problems in people who consumed whiting andred mullet caught in the southern Black Sea during the fishing seasons of 2017–2018. The carcinogenic risk index (CRI) for whitingand red mullet was also considered insignificant.Keywords: Heavy metals, Black Sea, fish, risk assessment, target hazard quotient, carcinogenic risk indexPlease cite this article in press as: Bat L, Öztekin A, Arici E, Şahin F. Health risk assessment: heavy metals in fish from the southernBlack Sea. Foods and Raw Materials. 2020;8(1):115–124. DOI: http://doi.org/10.21603/2308-4057-2020-1-115-124.Copyright © 2020, Bat et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 InternationalLicense (http://creativecommons.org/licenses/by/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix,transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license.Foods and Raw Materials, 2020, vol. 8, no. 1E-ISSN 2310-9599ISSN 2308-4057116Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124subject of sea contamination in Descriptor 8“Concentrations of contaminants are at levels notgiving rise to pollution effect” and Descriptor 9“Contaminants in fish and other seafood for humanconsumption do not exceed levels established byCommunity legislation or other relevant standards” [6].The objective of the MSFD with concern to Descriptors8 and 9 is to ensure that contaminants are represented infoods in safe amounts.According to the main guideline of theEuropean Union, European seas are to obtain theGood Environmental Status (GES) by 2020. Theabovementioned facts make studies of chemical elementsin commercial fish extremely relevant.The current study featured two commercialdemersal fish species and assessed the heavy metalcontamination, as well as the risk that the detected heavymetals represent for human health. The current studyconcentrated on the effect of Cd, Hg, Pb, Cu, and Zn onconsumers’ health. The concentrations of the metalswere measured in the muscle tissues of whiting andred mullet caught along the Sinop coast of the southernBlack Sea and sold on fish markets. The research alsoincluded a thorough analysis of scientific literature onthe amounts of Cd, Hg, Pb, Cu, and Zn in Black Seawhiting and red mullet. The obtained results could helpin achieving the goals set by MSFD 2008/56/EC [6].STUDY OBJECTS AND METHODSSample Collection. Twenty specimens of whitingand red mullet were purchased on fish markets. Thesampling was conducted during the fishing seasons ofFigure 1 Fishing area2017 and 2018 on the Sinop coast of the Black Sea (Fig. 1).The fish samples were processed according to themethod depicted by Bernhard and UNEP [6–8]. Theedible tissues of M. merlangus L. and M. barbatus L.were dissolved with Suprapur® HNO3 (nitric acid)using a microwave digestion system. The elementalconcentrations (Cd, Hg, Pb, Cu, and Zn) of the digestededible samples of whiting and red mullet were studiedusing the methods recognized by the EnvironmentalFood Analysis Lab Industry and Trade Inc.Fish tissues were prepared using an inductivelycoupled plasma mass spectrometer (ICP-MS), basedon m-AOAC 999.10 (Association of Official AnalyticalChemists with TS EN ISO IEC 17025 AB-0364-Treferences number) and CSN EN 15763 EuropeanStandards. The presence and quantity of the metalswere detected according to the instrumental reaction ofthe equipment. The results were given as mg·kg–1 wetweight (wt.).Health risk assessment. The risk assessment forinfants, children, and adults was performed to estimatethe possible hazard associated with the consumption ofheavy metals contained in the Black Sea fish. The riskexposure demands taking the mean daily intake of theheavy metals (mg/kg/day). The estimated daily intake(EDI) is subjected to the element levels and the amountof ingestion of fish. The EDI of heavy metals wascalculated according to the equation below:EDI =Cmetal × WfishBW (1)where Cmetal is the amounts of elements in edible tissues;Wfish Cmetal34°50&#39;0&#39;&#39;E 34°55&#39;0&#39;&#39;E 35°0&#39;0&#39;&#39;E 35°5&#39;0&#39;&#39;E 35°10&#39;0&#39;&#39;E 35°15&#39;0&#39;&#39;E42°5&#39;0&#39;&#39;N42°0&#39;0&#39;&#39;N41°55&#39;0&#39;&#39;NBLACK SEABLACK SEATURKEYSinop117Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124Wfish represents the daily mean ingestion of fish givenas 0.013, 0.027, and 0.041 kg/day for infants, children,and adults, respectively [10]; BW is the body weightof 10 kg for infants, 30 kg for children, and 70 kg foradults.The target hazard quotient (THQ) has been used inmany studies to analyze the potential non-carcinogeniceffect of the metals in the edible tissues of fish. TheEDI (mg/kg of body wt. per day) of each heavy metalwas related with the reference dose (Rf. D, mg/kg/day)as described in the equation below [11–13]:(2)Rf. D. is the oral reference dose for Zn, Cu, Pb,Hg, and Cd as suggested by the US EnvironmentalProtection Agency, i.e. 0.3, 0.04, 0.004, 0.0005, and0.001 mg/kg/day, respectively [14, 15]. However, inthe Risk Assessment Information System (RAIS), themercury inorganic salts Rf. D. value is 0.0003, andthere is no Rf. D. value for lead and compounds [15].In contrast, oral slope factor is given only for lead andcompounds as 0.0085 mg/kg/day [16]. The hazard index(HI) was defined as the sum of the THQs as described inthe equation below:HI= THQ (Zn) + THQ (Cu) + THQ (Pb) ++ THQ (Hg) + THQ (Cd) (3)The HI was used in this study to describe thecumulative non-carcinogenic effect. If HI > 1.0, then theEDI of a specific element exceeds the Rf. D, showingthat there is a potential risk associated with that element.The risk index (RI) represents the probability ofdeveloping any type of cancer over a lifetime. It iscalculated by integrating the EDI with the respectiveoral slope factors (SF) for heavy metals. Slope factors(SF) are used to reckon the risk of cancer along withexposure to a carcinogenic or probably carcinogenicmatter [17]. The description is presented in the equationbelow:RI= EDI x SF (4)The RI was considered insignificant if the RI was< 10–6; the RI was considered allowable or tolerable ifRI was 10–6 < RI < 10–4; the RI was consideredsignificant if the RI was > 10–4.RESULTS AND DISCUSSIONThe average amounts of the heavy metals in BlackSea whiting and red mullet are given in Fig. 2. Theamounts of heavy metals in both M. merlangus L.and M. barbatus L. decreased in the following order:Zn > Cu > Pb > Hg > Cd. The essential metals Zn andCu were represented in higher amounts due to theirbiological functions, whereas the toxic metals Pb, Hg,and Cd have no biological functions, and their amountsin fish tissues were considerably lower.Figure 2 Heavy metal amounts with standard deviation for Cd,Hg, Pb, Cu, and Zn in the edible tissues of M. merlangus L.and M. barbatus L. from the Black Sea coasts caught in 2017and 20182017 20180.0160.0120.0080.0040M. merlangus M. barbatusmg/kg wet wt0.040.030.020.0102017 2018mg/kg wet wt0.080.060.040.0202017 2018mg/kg wet wt0.30.20.102017 2018mg/kg wet wt10864202017 2018mg/kg wet wtCdHgPbCuEDI = ZnCmetal × WfishBW118Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124In this study, the heavy metal amounts in edibletissues varied according to the species. Cd, Hg, and Cuwere high in M. barbatus, whereas M. merlangus provedrich in Pb and Zn. These differences may be related tohabitat and feeding habits. The red mullet is demersalfish found near sand, gravel, and mud bottoms of thecontinental shelf. It feeds on small benthic mollusks,crustaceans, and worms. The whiting is benthopelagicfish found mostly near gravel and mud bottoms. Lessfrequently, it can be found on rock and sand. Thewhiting feeds on crabs, shrimps, mollusks, polychaetes,and small fish [17].Cu and Zn are relatively safe for living biota.Therefore, the permissible values of such essentialheavy metals as Cu and Zn are not available in thecurrent European Union and TFC regulations. However,they can be harmful if consumed in large amounts.According to the Ministry of Agriculture, Forestry, andFisheries of the UK (MAFF), the maximal tolerablelimits of Cu and Zn are 20 and 50 mg/kg wet wt.,respectively [18]. In this study, the amount of heavymetal detected in whiting and red mullet was found to besignificantly lower than these values.Similarly, the present study revealed that toxic metalvalues (Cd, Hg and Pb) in edible tissues of whiting andred mullet were below the permissible values (0.05,0.5, and 0.3 mg/kg wet wt.) set by European UnionCommission Regulation and Turkish Food Codex [19,20]. The Global Agriculture Information Network(GAIN) Report of the Russian Federation defined theTable 1 Estimated daily intakes (EDI) of elements in the edible tissues of Merlangius merlangus L. from the southern Black SeaHeavy metals EDI (2017), mg/day/kg body wt. EDI (2018), mg/day/kg body wt.Infants Children Adults Infants Children AdultsCd 0.0000156 0.0000108 0.0000070 0.0000182 0.0000126 0.0000082Hg 0.0000273 0.0000189 0.0000123 0.0000351 0.0000243 0.0000158Pb 0.0000780 0.0000540 0.0000351 0.0001040 0.0000720 0.0000468Cu 0.0002730 0.0001890 0.0001230 0.0002340 0.0001620 0.0001054Zn 0.0114400 0.0079200 0.00515428 0.0120900 0.0083700 0.0054471Table 2 Estimated daily intakes (EDI) of elements in edible tissues of Mullus barbatus L. from the southern Black SeaHeavymetalsEDI (2017), mg/day/kg body wt. EDI (2018), mg/day/kg body wt.Infants Children Adults Infants Children AdultsCd 0.0000234 0.0000162 0.0000105 0.0000208 0.0000144 0.00000937Hg 0.0000494 0.0000342 0.0000222 0.0000442 0.0000306 0.0000199Pb 0.0000585 0.0000405 0.0000263 0.0000715 0.0000495 0.0000322Cu 0.0004030 0.0002790 0.0001815 0.0003510 0.0002430 0.00015814Zn 0.0093600 0.0064800 0.0042171 0.0072800 0.0050400 0.0032800Table 3 Target hazard quotients (THQ) and hazard index (HI) of elements consumed with Merlangius merlangus L. caught nearthe southern coast of the Black Sea in 2017 and 2018HeavymetalsTHQ (2017) THQ (2018)Infants Children Adults Infants Children AdultsCd 0.0156000 0.0108000 0.00702857 0.0182000 0.0126000 0.0082000Hg 0.0546000 0.0378000 0.0246000 0.0702000 0.0486000 0.03162857Pb 0.0195000 0.0135000 0.008785714 0.0260000 0.0180000 0.011714286Cu 0.0068250 0.0047250 0.0030750 0.0058500 0.0040500 0.00263571Zn 0.0381330 0.0264000 0.01718095 0.0403000 0.0279000 0.01815714HI 0.1346580 0.0932250 0.060670238 0.1605500 0.1111500 0.072335714Table 4 Target hazard quotients (THQ) and hazard index (HI) of elements consumed with Mullus barbatus L. caught nearthe southern coast of the Black Sea in 2017 and 2018HeavymetalsTHQ (2017) THQ (2018)Infants Children Adults Infants Children AdultsCd 0.0234000 0.0162000 0.010542857 0.0208000 0.0144000 0.009371429Hg 0.0988000 0.0684000 0.044514286 0.0884000 0.0612000 0.039828571Pb 0.0146250 0.0101250 0.006589286 0.0178750 0.0123750 0.008053571Cu 0.0100750 0.0069750 0.004539286 0.0087750 0.0060750 0.003953571Zn 0.0312000 0.0216000 0.014057143 0.0242666 0.0168000 0.010933333HI 0.1781000 0.1233000 0.080242857 0.160116667 0.1108500 0.072140476119Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124permissible amounts of Cd, Hg, and Pb as 0.2, 0.5, and1 mg/kg wet wt., respectively [21].Tables 1 and 2 present the EDI values for whitingand red mullet caught near the Sinop coast of the BlackSea in 2017 and 2018 for infants, children, and adults.Tables 3 and 4 feature the THQ and HI values.The EDI levels of Cd, Hg, Pb, Cu, and Zn werevery low for both whiting and red mullet. Thesevalues were observed to be lower than their Rf. D.values. Likewise, THQ levels of these elements werevery low. The HI values for infants were observedto be higher than those for children and adults.This result suggests that, at a relatively high levelof exposure, infants will be more likely at risk thanchildren and adults. Obviously, infants weigh muchless than children and adults. However, the total noncarcinogenicindices (HI), which is the sum of THQvalues for all the heavy metals studied for each samplingyear, were lower than the threshold value of 1.0.Therefore, there were no health risks for infants,children, and adults who consumed whiting and redmullet caught near the southern coast of the Black Seaduring the fishing seasons of 2017 and 2018.In the Risk Assessment Information System, theSP value is given for Pb and its compounds only.The lifetime of a person is stated to be 70 years onaverage, while the exposure duration is assumed to be26 years [16]. Tables 5 and 6 show carcinogenicconcentration of consumed fish (CDI), hazard quotient(HQ), risk index (RI), and hazard risk (HI) of heavymetals in M. merlangus and M. barbatus caught near thesouthern coast of the Black Sea. The carcinogenic riskfor whiting and red mullet was lower than 10–6 and isconsidered insignificant. The lowest RI was found in redmullet in 2017.The results of this study were compared with thestudies that featured Merlangius merlangus and Mullusbarbatus from the Black Sea. They are presented inTables 7 and 8, respectively.In general, the amount of heavy metal found in bothMerlangius merlangus and Mullus barbatus proved tobe lower than that in other studies. Likewise, Zn is theheaviest metal found in both species. It is followed byCu, Pb, Cd, and Hg. When compared, Zn, Cu, and Pbwere found in high amounts in the whiting collectednear the Amasra coasts of the southern Black Sea [31].Hg was the highest in the whiting caught near the shoresof Istanbul in the Black Sea [30]. Cd was detected inboth fish species caught near the Trabzon shores. Thehighest Hg level species was obtained from M. barbatuscaught near the shores of Istanbul and Kocaeli in theBlack Sea [37]. The highest Pb value was found in thered mullet fished near the Kastamonu shores of the BlackSea [45].The differences in the amounts of heavy metalsfound in these fish species may be due to the fact thatthey were caught during different fishing seasonsand in different areas of the Black Sea. Metabolism,physiology, and feeding habits of the fish are differentin different seasons. The pollution load also varies indifferent areas of the Black Sea coast [2]. Similarly,one should not dismiss different applications in heavymetal measurements, equipment accuracy, and humanerror. Although there are some exceptions, the amountsof heavy metals in these fish species proved to be low.Therefore, they posed no threat to human health.CONCLUSIONThe research featured the effect of Cd, Hg, Pb, Cu,and Zn on the health of infants, children, and adults whoTable 5 Carcinogenic concentration of consumed fish (CDI), hazard quotient (HQ), risk index (RI), and hazard risk (HI)of elements in Merlangius merlangus L. caught near the southern coast of the Black Sea in 2017 and 2018Heavymetals2017 2018CDI, mg/kg/day HQ RI CDI, mg/kg/day HQ RICd 0.0000026 0.0070290 0.0000030 0.0082000Hg 0.0000045 0.0246000 0.0000058 0.0316290Pb 0.0000130 – 0.00000011 0.0000170 – 0.00000014Cu 0.0000450 0.0030750 0.0000390 0.0026360Zn 0.0019144 0.0171810 0.0020232 0.0181570HI 0.0518850 0.00000011 0.0606220 0.00000014Table 6 Carcinogenic concentration of consumed fish (CDI), hazard quotient (HQ), risk index (RI), and hazard risk (HI)of elements in Mullus barbatus L. caught near the southern coast of the Black Sea in 2017 and 2018Heavymetals2017 2018CDI, mg/kg/day HQ RI CDI, mg/kg/day HQ RICd 0.0000039 0.0105430 0.0000034 0.0093710Hg 0.0000082 0.0445140 0.0000082 0.0398290Pb 0.0000097 – 0.000000083 0.0000119 – 0.0000001Cu 0.0000670 0.0045390 0.0000580 0.0039540Zn 0.0015663 0.0140570 0.0012182 0.0109330HI 0.0736530 0.000000083 0.0640870 0.0000001120Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124Table 7 Comparison of the amounts (ppm) of heavy metals in the edible tissues of Merlangius merlangus L. caught near variousareas of the Black Sea coastLocation dw/ww Metals Ref.Zn Cu Pb Cd HgBlack Sea d.w. 48.6 ± 3.9 1.25 ± 0.10 0.93 ± 0.07 0.55 ± 0.04 – [22]Black Sea d.w. 8.86–163.28 0.91–8.95 – – – [23]Trabzon w.w. 8.62 ± 0.54 0.88 ± 0.12 0.25 ± 0.07 0.01 ± 0.00 – [24]Sinop 12.9 ± 4.14 2.90 ± 0.78 0.46 ± 0.08 0.04 ± 0.01 –Bartın 5.73 ± 0.37 0.77 ± 0.07 0.18 ± 0.04 0.02 ± 0.00 –İstanbul d.w. 6.03 ± 0.55 0.50 ± 0.10 0.19 ± 0.02 – [25]Black Sea w.w. 65.4 ± 4.2 1.32 ± 0.11 0.53 ± 004 0.21 ± 0.02 84 ± 5 μg·kg–1 [26]Sinop d.w. – – < 0.05 < 0.02 < 0.05 [27]Samsun – – < 0.05 < 0.02 < 0.05Samsun, Ordu, Trabzon, Rize d.w 20.6 ± 2.1 1.8 ± 0.2 0.46 ± 0.05 0.18 ± 0.02 – [28]Samsun, Sinop, Terme, FatsaOrdud.w. 31.34 ± 1.61 3.72 ± 0.59 0.58 ± 0.03 0.002 ± 0.000 not detect [29]İstanbul w.w. 4.248–30.842 0.001–4.915 0.004–1.581 0.001–0.151 0.003–0.491 [30]Amasra-West Black Sea w.w. 77.99 ± 46.91 8.53 ± 2.14 6.80 ± 5.88 0.40 ± 0.29 – [31]Samsun- Turkey d.w. 58 ± 3.528.3 ± 12.3 ± 0.72.7 ± 0.70.9 ± 0.2not detect0.2 ± 0.03not detect– [32]Terkos d.w. – – 15 0.35 0.07 [33]Sakarya – – 12 0.24 < 0.01Bafra – – 15 0.07 0.09Ordu – – 13 0.22 0.5Trabzon-Turkey d.w. 22.76 ± 2.01 1.02 ± 0.05 0.08 ± 0.03 0.04 ± 0.01 0.05 ± 0.01 [34]Black Sea d.w. 8.49 0.51 0.01 – – [35]Sinop d.w. 22.82–34.33 2.85–5.26 0.02 0.08–0.18 – [36]Black Sea d.w. 18 ± 1.4 2.5 ± 0.06 0.05 ± 0.01 0.03 ± 0.01 0.33 ± 0.02 [37]Eastern Black Sea, TurkeyOrdu-Samsund.w. 21.5 1.56 0.024 0.031 – [38]West Black Sea w.w. 18.1 ± 0.3 1.28 ± 0.07 – – – [39]Sinop d.w. 16.34 ± 3.83 1.20 ± 0.31 0.69 ± 0.34 0.027 ± 0.012 – [40]Trabzon-Turkey w.w. – – 0.02 ± 0.00 4.05 ± 0.14 – [41]Sinop w.w. 3.4 < 0.5 < 0.05 < 0.02 < 0.05 [42]Sinop w.w. 43 ± 6 0.41 ± 0.02 0.88 ± 0.006 0.075 ± 0.006 not detect [43]Samsun w.w. 5.04 ± 0.58 1.28 ± 0.09 1.41 ± 0.23 0.06 ± 0.02 – [44]Sinop 3.47 ± 0.27 0.92 ± 0.08 0.63 ± 0.06 0.05 ± 0.003 –Kocaeli 3.99 ± 0.5 1.46 ± 0.18 0.69 ± 0.12 0.06 ± 0.01 –Kastamonu w.w. 5.45 ± 1.12 4.52 ± 0.70 6.12 ± 1.45 0.24 ± 0.02 – [45]Giresun w.w. 3.77 ± 0.22 2.40 ± 0.25 0.05 ± 0.00 0.66 ± 0.08 – [46]Trabzon 5.65 ± 0.58 1.62 ± 0.25 1.30 ± 0.31 0.12 ± 0.03 –Rize 4.08 ± 0.36 1.65 ± 0.26 1.29 ± 0.21 0.08 ± 0.02 –Southwestern Black Sea w.w. 23.54 ± 6.77 2.44 ± 0.54 0.36 ± 0.42 0.02 ± 0.01 0.01 ± 0.01 [47]Black Sea w.w. – – 0.099 0.013 0.081 [48]Sinop w.w. 7.11–17.88 0.18–0.33 0.03–0.09 0.007–0.0085 0.01–0.017 [49]Sinop w.w. 9.70 ± 1.9 2.90 ± 0.99 1.17 ± 1.01 0.02 ± 0.01 – [50]Kastamonu 6.74 ± 1.63 2.35 ± 0.36 1.18 ± 0.45 0.03 ±0.01 –Zonguldak 6.24 ± 0.8 2.25 ± 0.25 0.86 ± 0.34 0.03 ± 0.01 –Sinop w.w. 12.63 ± 0.2218.52 ± 0.600.59 ± 0.062.10 ± 0.670.19 ± 0.020.90 ± 0.280.03 ± 0.000.22 ± 0.030.13 ± 0.010.23 ± 0.00[51]Western Black Sea w.w. – – – – 0.01 ± 0.01 [52]d.w.= dry wt.; w.w. = wet wt.121Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124Location dw/wwMetals Ref.Zn Cu Pb Cd HgBlack Sea d.w. 106 ± 9.1 0.98 ± 0.07 0.84 ± 0.07 0.45 ± 0.04 – [22]Black Sea d.w. 1.424–63.290 0.380–2.714 – – – [23]Trabzon w.w. 8.26 ± 0.77 1.30 ± 0.13 0.22 ± 0.08 0.02 ± 0.00 – [24]Sinop 10.5 ± 2.03 0.87 ± 0.09 0.39 ± 0.03 0.03 ± 0.00 –İstanbul d.w. 7.573 ± 0.389 – 0.727 ± 0.141 0.208 ± 0.017 – [25]Black Sea w.w. 75.5 ± 5.3 0.96 ± 0.08 0.36 ± 0.03 0.17 ± 0.02 36 ± 2 μg·kg–1 [26]Sinop d.w. – – 0.0525 < 0.02 < 0.05 [27]Samsun – – 0.0815 < 0.02 < 0.05Samsun, Ordu, Trabzon, Rize d.w. 17.8 ± 1.8 1.4 ± 0.1 0.40 ± 0.04 0.23 ± 0.02 – [28]Samsun, Sinop, Terme, Fatsa Ordu d.w. 23.71 ± 0.71 3.14 ± 0.31 0.92 ± 0.12 0.020 ± 0.002 – [29]Amasra w.w. 16.03 ± 14.05(3.48–40.72)4.08 ± 2.79(1.23–9.21)1.11 ± 1.60(0.09–7.00)0.11 ± 0.13(0.02–0.55)– [31]Trabzon-Turkey d.w. 27.36 1.12 0.10 0.02 0.11 [32]Sinop d.w. 6.95–18.43 4.93–7.74 0.09–0.31 0.02 – [53]Black Sea (İstanbul and Kocaeli) d.w. 14.6 ± 1.3 1 ± 0.18 0.02 ± 0.01 0.02 ± 0.01 0.47 ± 0.02 [37]Eastern Black Sea, Turkey Ordu-Samsund.w. 19.7 1.36 0.020 0.018 – [38]West Black Sea d.w. 36.4 ± 3.2 2.28 ± 0.03 – – – [39]Sinop d.w. 17.15 ± 3.78 0.95 ± 0.41 0.82 ± 0.34 0.035 ± 0.018 – [40]Trabzon-Turkey w.w. – – < LOD 3.38 ± 0.06 – [41]Sinop d.w. 3.2 < 0.5 < 0.05 < 0.02 < 0.05 [42]Sinop d.w. 10.64–19.53 2.79–5.45 0.11–0.45 0.03–0.19 – [54]Samsun w.w. 4.95 ± 0.6 1.27 ± 0.19 1.76 ± 0.40 0.20 ± 0.11 – [44]Sinop 9.49 ± 0.38 2.38 ± 0.12 2.94 ± 0.81 0.07 ± 0.02 –Kocaeli 5.71 ± 0.88 1.4 ± 0.12 0.88 ± 0.12 0.06 ± 0.005 –Kastamonu w.w. 6.14 ± 1.46 2.35 ± 0.38 7.21 ± 1.56 0.28 ± 0.03 – [45]Giresun w.w. 6.02 ± 0.45 1.99 ± 0.18 0.45 ± 0.05 0.04 ± 0.00 – [46]Trabzon 7.15 ± 0.64 1.74 ± 0.13 1.03 ± 0.10 0.12 ± 0.03 –Rize 5 ± 0.31 1.81 ± 0.15 1.30 ± 0.16 0.09 ± 0.02 –Southwestern Black Sea w.w. 20.80–34.94 1.36–11.85 0.03–1.70 0.02–0.05 0.01–0.03 [47]Ordu d.w. 44.85 ± 7.1183.13 ± 8.41.64 ± 0.373.95 ± 0.740.81 ± 0.041.54 ± 0.360.8 ± 0.020.91 ± 0.02– [55]Black Sea w.w. – – 0.165 0.016 0.032 [48]Sinop w.w. 5.61–11.8 0.27–0.49 0.025–0.06 0.007–0.011 0.015–0.021 [49]Romania w.w. – 3.486 ± 2.45 0.32 ± 0.25 0.026 ± 0.001 – [56]Romania w.w. – – – – 0.035 ± 0.01(0.021–0.072)[57]West Black Sea w.w. – – – – 0.03 ± 0.02 [52]d.w.= dry wt.; w.w. = wet wt.Table 8 Comparison of the amounts (ppm) of heavy metals in the edible tissues of Mullus barbatus L. caught near various areasof the Black Sea coastconsumed whiting (M. merlangus L.) and red mullet(M. barbatus L.) caught near the southern coast of theBlack Sea in 2017 and 2018. For all age groups, the EDIvalues for each heavy metal decreased in the followingorder: Zn > Cu > Pb > Hg > Cd. The mean values ofCd, Hg, Pb, Cu, and Zn in the edible tissues were 0.013,0.024, 0.07, 0.195, and 9.05 mg/kg wet wt. for whitingand 0.017, 0.036, 0.05, 0.29, and 6.4 mg/kg wet wt. forred mullet, respectively. The differences might havebeen caused by the fact that the samples were caughtduring different fishing seasons and in different areas ofthe Black Sea.In all cases, HI values for each metal were ˂ 1,suggesting no health risk. The concentrations also metthe standards set up by regulatory bodies of Turkey andthe European Union. The RI values for whiting and redmullet did not exceed the insignificant limit (10–6). Inaddition, these two commercial species caught near theSinop coast showed no carcinogenic potential.122Bat L. et al. Foods and Raw Materials, 2020, vol. 8, no. 1, pp. 115–124CONTRIBUTIONThe authors were equally involved in writing themanuscript and are equally responsible for plagiarism.CONFLICT OF INTERESTThe authors declare that there is no conflict ofinterests regarding the publication of this paper.