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(48-01) Hexachlorobenzene uptake in crayfish and aquatic macrophyte. Lindström-Seppä, Pirjo1, Honkalampi-Hämäläinen, Ulla*,2, Tarhanen, Juhani3, Henttonen, Paula2, Huuskonen, Jari2, 1 University of Kuopio, P.O.Box 1627, Kuopio, FINLAND2 University of Kuopio, P.O.Box 1627, Kuopio, FINLAND3 University of Kuopio, P.O.Box 1627, Kuopio, FINLAND ABSTRACT- Hexachlorobenzene (HCB) is one of the most common environmental pollutants due to its use as fungicide and release in combustion processes. The aim of the present study was to clarify the uptake of HCB by wild crayfish (Astacus astacus) collected from clean water and aquatic macrophyte, Lemna minor (axenic laboratory strain, ITM). Uptake of HCB was investigated in laboratory conditions. Lemna was used as a model plant, because it is easy to grow in laboratory and serves as food for crayfish when available. Crayfish and lemna were exposed in aquaria at 16 C to two micrograms of HCB per liter in chlorine free water for 2, 7 and 14 days. This HCB concentration is likely to be found in polluted environment, too. The tissues were homogenized in concentrated sulfuric acid. Hexachlorobenzene was extracted with hexane and analysed with GC-MS. The uptake of hexachlorobenzene was fast and took place already within two days. The highest concentrations of HCB were found throughout the study period in crayfish hepatopancreas, where the levels were at least ten times higher than in gills or in muscle. Only very low levels were detected in greengland and epidermal and subepidermal tissues. The levels decreased during the two weeks follow-up e.g. in muscle to one third of the highest concentration. The variation of HCB concentrations was smaller in hepatopancreas samples collected after two days exposure compared to the quite large variation in samples collected after two weeks exposure. HCB concentration found in lemna after one week was lower than in crayfish hepatopancreas however higher than in other tissues studied. In lemna the preliminary test showed that HCB might be metabolized to its main metabolite, pentachlorophenol. It is obvious the hexachlorobenzene is readily taken up by lemna and crayfish, hepatopancreas being the target organ. Key words: hexachlorobenzene, crayfish, lemna, uptake |
