Bioaccumulation and MFO enzyme induction of di, tri- and tetrachlorodibenzofurans and 2,3,7,8-TCDD in juvenile rainbow trout

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:40029

Muir, D; Yarechewski, A; Metner, D; Lockhart, L ^[1]

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1. Department of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.

Juvenile rainbow trout (3--10 g) were exposed to dietary 2,8-di-, 2,3,8-tri-, and 2,3,7,8-tetrachlorodibenzofuran (TCDF) and to 2,3,7,8-TCDD in separate experiments. Elimination was studied for up to 180 days following a 30 days exposure. The authors compared the MFO induction potency, assimilation efficiencies, biomagnification factors and elimination rates of di and trichlorofurans, which are the major PCDD/F congeners in bleached (partial ClO{sub 2} substitution) kraft pulp mill effluent, with those of TCDD/F. 2,8-D{sub 2}CDF and 2,3,8,-T{sub 3}CDF were rapidly eliminated with half-lives (t{sub 1/2}) of 6 to 1 0 days for both compounds. By contrast TCDF and TCDD were slowly eliminated by the trout (t{sub 1/2} = 70 and 80 d, respectively). Biomagnification factors for 2,8-D{sub 2}CDF and 2,3,8,-T{sub 3}CDF were < 0.1 and there was evidence of extensive transformation of T{sub 3}CDF to polar degradation products. P450 MFO (EROD) activities in fish exposed to 100 or 300 ng/g of 2,3,8,-T{sub 3}CDF were 5 to 15-fold elevated (over controls); 2,8-D{sub 2}CDF exposure had no effect. Exposure to 413 pg/g TCDD in food resulted in 4-fold elevation in EROD after 30 days corresponding to a concentration in muscle of 120 pg/g wet wt. MFO activity returned to control levels 24 days after cessation of exposure to 2,3,8,-T{sub 3}CDF and 120 days after exposure to TCDD.

• OSTI ID: 40029
• Report Number(s): CONF-9410273--
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BENZOFURANS
BIOLOGICAL ACCUMULATION
DIOXIN
ENZYME INDUCTION
METABOLISM
MIXED-FUNCTION OXIDASES
SENSITIVITY
TROUT
WATER POLLUTION