The assessment of the bioaccumulation of selected halogenated xenobiotics in the aquatic food chain

audiovizuální tvorba

angličtina

Halogenated compounds as polychlorinated biphenyls (PCBs) or pesticides (DDT or hexachlorocyclohexanes HCH) are the main representatives a large group of xenobiotics called persistent organic pollutants (POPs) which were once (or still are) used in many applications, but were early recognised as serious threat to the environment. These chemicals tend to persist in the environment for a long period of time and accumulate in the food web with a high resistance to be metabolised and excreted. The aim of this study was to assess the degree of contamination in the aquatic food chain by using selected fish and bird species as bioaccumulation markers (bream, pike-perch, perch, tench; cormorant). The samples of prepared fat tissue (from skin, muscle and viscera) from caught individuals were analysed by means of high resolution gas chromatography by both electron capture and mass detectors. Based on the results, the levels of monitored pollutants corresponded very well with a position of given species within the food chain and reflected its feed habits. The concentrations of 7 major PCB congeners and pesticides (DDTs, HCH and HCB) in water and sediment samples were mainly units or tenths of ppb whereas the levels in phytophagic fish were approx. hundredfold higher and in predatory fish and birds reached the values of units and even tens of ppm. The results clearly illustrate the process of bioaccumulation of these pollutants through the aquatic food chain and follow interspecies differences. The comparison between more sampling areas (polluted and relatively unpolluted) and species was made as well.

bioaccumulation, water, fish, halogenated xenobiotics, gas chromatography

LÁNA, R.; VÁVROVÁ, M.; HROCH, M.; VEČEREK, V.

5. 12. 2007

Port Dundas, Glasgow, G4 9TH UK