KINETICS OF BIOCONCENTRATION AND CLEARANCE OF 28 POLYCHLORINATED BIPHENYL CONGENERS IN ZEBRAFISH (BRACHYDANIO-RERIO)

Bioconcentration experiments were performed on 28 polychlorinated biphenyl (PCB) congeners with N-Cl = 2 to N-Cl = 10, evaluating them simultaneously. Bioconcentration factors (BCFs) were calculated from the uptake rate constant (k(1)) and the clearance rate constant (k(2)) as BCF = k(1)/k(2). BCFs on a wet weight basis ranged from 7710 to 940,000. They were correlated with octanol-water partition coefficients (P). The curvilinear relationship between log BCF and log P based upon data covering the log P range 5.06 to 8.18. About a log P of 7.38, a range of ''optimal lipophilicity,'' results in highest BCFs for PCBs, above which the degree of bioconcentration decreases. (C) 1994 Academic Press, Inc.