Contaminated food was prepared by exposing pink shrimp (Penaeus duorarum) to 10 μg/L of radiolabeled (14C) 1,2,4-trichlorobenzene (TCB) for twelve days; whole body concentration of TCB in the exposed shrimp was 0.59μg/g. Juvenile spot (Leiostomus xanthurus), a marine fish, were then fed the TCB-contaminated shrimp at a daily ration of 10% body weight for 28 days, and they accumulated <0.05 μg/g TCB (detection limits). Spot, exposed to nominal 10 μg/L TCB in water for 28 days and fed uncontaminated food, bioconcentrated TCB approximately 100 times the aqueous exposure concentration. Equilibrium was attained in these fish within seven days, and fish depurated TCB to concentrations <0.1μg/g within 24 h after being placed in TCB-free water. Spot, exposed simultaneously to the contaminated food and water described above, bioaccumulated TCB equal to the aqueous exposure treatment.
Pharmacokinetic uptake and depuration rate constants were used to compare the potential for spot to bioaccumulate TCB, a moderately lipophilic compound, to that for chlordecone (Kepone), a highly lipophilic compound. Our results were also compared to those from a TCB bioaccumulation study with freshwater species; both studies indicated that TCB was moderately accumulated from contaminated water and that accumulation from contaminated food was negligible.