Lubomir Makedonski

Organochlorine pesticides and PCBs in marine fish

Abstract Organochlorine pesticides (such as 1,1,1-trichloro - 2,2 - bis (4-chlorophenyl) ethane (DDT) and its metabolites) and polychlorinated biphenyls (PCBs) are classified as Persistent Organic Pollutants (POPs) and are present in the contamination pattern of marine environments world-wide. Concentrations of PCBs and DDTs were measured in two marine species: garfish (Belone belone) and red mullet (Mullus barbatus). Samples were collected from Black Sea, Bulgaria during 2007 - 2010. The DDTs and PCBs were determined by gas chromatography - mass spectrometry. Concentrations in muscle tissue of garfish ranged from 80.89 to 118.04 ng/g wet weight for total DDTs. DDTs concentration in red mullet was found 104.59 ng/g ww. PCB concentrations in garfish varied in the range of 40.04 and 65.62 ng/g ww. In muscle tissue of red mullet PCB concentrations were found 34.12 ng/g ww. The levels of DDTs and PCBs in garfish and red mullet from the Black Sea were comparable with those found in other marine ecosystem.

Investigation about the presence of organochlorine pollutants in mussels from the Black Sea, Bulgaria

Abstract The aim of this study was to investigate the presence of polychlorinated biphenyls (PCBs), organochlorine pesticides (HCB, DDT and its metabolites) and HCBD in mussels from Bulgarian Black Sea coast. Mussels (Mytilus galloprovincialis) are aquatic organisms which are immobile so that the concentration of pollutants should primarily be considered as an indication of local levels of organochlorine compounds. Samples were collected from three areas of Black Sea coast of Bulgaria in summer 2015. The fifteen congeners of PCBs, HCB, HCBD, DDT and its metabolites DDE and DDD were performed by gas chromatography system with mass spectrometry detection. The metabolites DDE and DDD were found in all analyzed mussel samples, but PCBs were not detected in any sample. DDE concentrations were found in mussels from 1.09 to 1.63 ng/g wet weight. In mussel total DDT concentrations (2.14 ng/g ww) were found comparable to those in mussels, sampled in 2013 and 2014 (1.87 ng/g ww). The levels of DDTs and polychlorinated biphenyls in mussels from the Black Sea were found comparable to levels measured in the same molluscs from neighbor seas - Mediterranean Sea and Adriatic Sea.

Organochlorine contaminants (PCBs, DDTs, HCB & HBDE) in fish from the Lake Varna and Lake Beloslav, Bulgaria

Abstract Concentrations of organochlorine compounds such as polychlorinated biphenyls (PCBs), DDT and its metabolites, hexachlorobenzene (HCB) and hexachlorobutadiene (HBDE) were determined in three fish species: goby (Neogobius melanostomus), golden grey mullet (Mugil auratus) and silverside (Atherina boyeri). Samples were collected from the Lake Varna and the Lake Beloslav in 2014. The edible fish tissues were analyzed in order to investigate the presence of pollutants in species from the lakes near Varna City, Bulgaria and compared the results to the levels in other aquatic ecosystems. The fifteen congeners of PCBs, HCB, HCBD, DDT and its two main metabolites DDE and DDD were determined by capillary gas chromatography system with mass spectrometry detection. The OCPs levels in the wild fish were found in the order DDTs > PCBs. The other contaminants HCB and HCBD were not detected or were below the analytical detection limit. Among the pesticides, essentially only the metabolites p, p’- DDE and p, p’- DDD were found. The concentrations of DDTs were determined from 2.66 to 17.97 ng/g wet weight and PCBs concentrations were found from 0.43 to 8.05 ng/g ww (in goby and golden grey mullet, respectively). The sum of the six Indicator PCBs did not exceed the European maximum limit 75 ng/g wet weight. The concentrations of DDTs and PCBs were found lower compared to those in similar fish species from other aquatic ecosystems.

Evaluation of toxic metal levels in edible tissues of three wild captured freshwater fishes

Abstract River ecosystems are vulnerable to heavy metal pollution. Fish samples are considered as one of the most indicative factors, in fresh water systems, for the estimation of trace metals pollution potential since they are the final chain of aquatic web. The objective of the present study is to evaluate the concentration of some toxic elements (As, Hg, Pb, Cd and Ni) in edible part of three wild fresh water fish species (zander (Sander lucioperca), wels catfish (Silurus glanis) and European carp (Cyprinus Carpio)) caught from Bulgarian part of Danube river collected during 2010. The Danube River is the European Unions longest and the continents second longest river that passes through or touches the borders of ten countries. It has a great importance in regard to biodiversity, economics and transportation. The elements (As, Pb, Cd and Ni) were assayed using Perkin Elmer Zeeman 3030 electrothermal atomic absorption spectrometer with an HGA-600 atomizer. Determination of Hg was performed using Milestone Direct Mercury Analyzer DMA-80. The results were expressed as μg/g dry weight. The order of heavy metal accumulation in the edible part of zander is As>Hg>Pb> Ni> Cd while the other two fish species show a different metal accumulation Hg > As >Pb> Ni > Cd. In all heavy metals, the accumulation of mercuric and arsenic proportion was significantly high in all three fish types.

Fat soluble vitamins and fatty acid composition of wild Black sea mussel, rapana and shrimp

Abstract Many studies suggest that marine molluscs are one of the most important dietary sources of fat soluble vitamins (E, D3 and A) and essential fatty acids (FA). The most commercially important species from the Bulgarian Black Sea are the Black mussel, rapana and shrimp. There is scarce information in the scientific literature about fat soluble vitamins and FA composition of these Black Sea molluscs. The aims of the present study are to determine and compare fat soluble vitamins content as well as relative daily intake, FA composition and atherogenic index (IA), thrombogenicity index (IT) and flesh-lipid quality index (FLQ) in wild Black Sea mussel (Mytilus galloprovincialis), rapana (Rapana venosa) and shrimp (Crangon crangon). Fat soluble vitamins were analysed simultaneously using RP-HPLC system. The FA profile was analysed by GC-MS. All of the analysed samples presented significant amounts of vitamin E, followed by vitamin A and D3. Black Sea molluscs are excellent sources of fat soluble vitamins, especially for vitamin D3 - one survey provides more than 100% of the RDI established in Bulgaria. The FA composition of total lipids showed significant differences and the present study revealed that SFA content was significantly higher than MUFA (p<0.001) and PUFA (p<0.001) (SFA>PUFA>MUFA) in shrimp and mussel whereas rapana showed opposite trends (PUFA>SFA>MUFA). The omega6/omega3 and PUFA/SFA ratios of the analysed species were greater than the FAO/WHO recommendations.

Fatty acid composition of Bulgarian Black Sea fish species

Abstract The fatty acid compositions of three Black Sea fish species turbot (Pseta maxima), red mullet (Mullusbarbatus ponticus) and garfish (Belone belone) were investigated. This species are considered as preferred for consumption in Bulgaria. Lipid extraction was done according to the Bligh and Dyer method. The fatty acid composition was determined by GC/MS. The saturated fatty acids amounts were 38.32 % for turbot, 35.44 % red mullet and 42.90% for garfish. Monounsaturated fatty acids were found in lowest level in comparison with other groups for garfish (23.65%) and turbot (24.85%) while for red mullet they have a highest value - 37.56%. Omega 3 polyunsaturated fatty acids as eicosapentaenoic (C 20:5 omega 3, EPA) and docosahexaenoic (C 22:6 omega 3, DHA) acids were found in highest levels in turbot (22.26%) and garfish (21.80%) and in lowest values of red mullet (9.35%). The results showed that the fish examined are good source of omega 3 polyunsaturated fatty acids, resulting in a very favourable omega 3 / omega 6 ratios, especially in turbot and garfish

Comparison of heavy metal concentration of some marine fishes from Black and Aegean Seas

Abstract Major part of healthy human diet consist of marine fish and seafood products. And it is not surprising that there are numerous studies based on metal accumulation in various fish species. Fish may also be used for heavy metal monitoring programs of marine environments due to their easy sampling, sample preparation and chemical analysis. Concentrations of lead, cadmium, nickel, copper, manganese, zinc, iron, chromium, total mercury and total arsenic were determined in edible part of two commercially valuable fish Greek aquaculture species European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) purchased from Bulgarian market during 2011. The concentration of metals was measured by atomic absorption spectrophotometry (AAS). The concentration of the heavy metals in examined fish species ranged as follow: Pb 0.008 - 0.013; Cd 0.0017 - 0.022; Ni 0.007 - 0.012; Cu 0.054 - 0.115; Mn 0.043 - 0.09; Zn 0.14 - 0.15; Fe 0.17 - 0.19; Cr 0.05 - 0.07; Hg 0.11 - 0.13; As 1.6 - 1.8 mg kg-1 wet weight, respectively. The concentration of the heavy metals obtained from this study is compared with the results of a Black Sea bluefish (Pomatomus saltatrix) caught during the same year. The concentration of metals was significantly affected by the sampling site and fish species. Difference in the heavy metal concentration between European sea bass, gilthead sea bream is observed for Cu, Mn, Zn and Fe. Although, the heavy metals in the edible parts of the investigated fish were in the permissible safety levels for human uses.