COMPARISON OF BIOCONCENTRATION FACTORS OF TETRACHLOROBENZYLTOLUENES IN THE GUPPY (POECILIA-RETICULATA) AND ZEBRA MUSSEL (DREISSENA-POLYMORPHA)

Preliminary bioconcentration factors (BCFs) were determined of six tet rachlorobenzyltoluenes (TCBTs) in guppies (Poecilia reticulata). BCFs and rate constants were derived by an iterative integration method. Wi th this method BCFs and rate constants can be derived from experimenta l data of a bioconcentration test, even if the concentration in the wa ter is not constant and steady state has not been reached. Log BCF val ues of TCBTs in guppies ranged from 1.67 to 2.68 L.kg(-1) on a wet wei ght basis. These values are much lower than the reported log BCF value s of TCBTs in zebra mussels (Dreissena polymorpha) determined with the same method. Biotransformation of TCBTs in guppies as an explanation for the higher log BCF values in zebramussel is discussed.