H. Dabrowska et Sw. Fisher, ENVIRONMENTAL-FACTORS AFFECTING THE ACCUMULATION OF SEDIMENT-SORBED HEXACHLOROBIPHENYLS BY CHANNEL CATFISH, Aquatic toxicology, 27(1-2), 1993, pp. 179-198
Channel catfish (Ictalurus punctatus) fingerlings were used to determi
ne kinetically the accumulation of two symmetrical hexachlorobiphenyl
(HCBP) isomers as a function of environmental temperature and sediment
organic carbon (OC) content (0.9% and 3.1%). Groups of fish were expo
sed to each contaminated sediment, spiked with C-14 radiolabelled (2,4
,5)2 or (2,3,5)2 HCBP (IUPAC No. 153 and 133) for up to 10 days at 13-
degrees-C or 20-degrees-C. The uptake clearance rates (k1) and elimina
tion rate constants (k2) were estimated using first-order uptake and e
limination models. Temperature was the more influential parameter test
ed. Both uptake clearance rates and bioaccumulation factors were affec
ted by changing temperature. Increasing temperature from 13-degrees-C
to 20-degrees-C resulted in a 2-4-fold increase of the k1, for both is
omers. Sediment OC content also affected the k1, although to a lesser
extent than temperature and not in a consistent way. Bioaccumulation f
actors estimated for the (2,4,5)2 isomer of HCBP were generally lower
than those for the (2,3,5)2 HCBP isomer. Increasing temperature and/or
sediment OC content resulted in a decrease of the BCFs for (2,3,5)2 i
somer but not for (2,4,5)2. These results indicate that environmental
hazard may be difficult to predict even when chemicals with similar K(
ow) values are considered.