Bioconcentration of 5,5′,6 -trichlorobiphenyl and pentachlorophenol in the midge, Chironomus riparius, as measured by a pharmacokinetic model

A two compartment pharmacokinetic model was developed which describes the uptake and elimination of 5,5′,6-trichlorobiphenyl (TCB) and pentachlorophenol (PCP) in the midge, Chironomus riparius. C. riparius were exposed to nominal TCB (2 μg L⁻¹) and PCP (9 μg L⁻¹) concentrations during a 16 h static uptake phase. Depuration was determined over approximately 45 h using a flowthrough system without feeding. The uptake clearance (P) was 330±61 ml g⁻¹ midge h⁻¹ for TCB and 55±4 ml g⁻¹ midge h⁻¹ for PCP, while measured bioconcentration factors (BCF) were 35,900 and 458 for TCB and PCP, respectively. Overall, the clearance-volume-based pharmacokinetic model predicted BCF values that were consistent with published values as well as with BCF values obtained from the octanol-water partition coefficient (K_OW).