Stanislava Georgieva

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.