Tissue distribution of [14C]DDT in the lobster after administration via intravascular or oral routes or after exposure from ambient sea water

A pharmacokinetic approach to studying the fate and distribution of ¹⁴C]DDT was employed using the lobster, a species of obvious economic importance. The radioactive pesticide was administered by 3 different routes; intravascular, oral and by exposure from the ambient water. After intravascular administration there was very rapid removal of ¹⁴C]DDT from the plasma accompanied by a strikingly persistent increase in the amount of radioactivity in the hepatopancreas. Most (>90%) of the radioactivity in this organ was shown by TLC to be the parent pesticide. Seven days after injection of ¹⁴C]DDT approximately 90% of the administered radioactivity was found in the hepatopancreas and the concentrations in this organ decreased with a $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of 46 days. One month after treatment with 0.1 mg/kg of ¹⁴C]DDT, the only other organs which contained more than 1% of the administered dose were egg masses and muscle. When the pesticide was administered to the lobster from ambient water or from food, the hepatopancreatic compartment again dominated, with more than 90% of the absorbed dose occurring in this organ 7 days after treatment. Studies conducted of residue levels in untreated lobsters indicated that the egg masses contained the largest concentration of total DDT metabolites (1 ppm). The hepatopancreas contained about 0.4 ppm while the carcass (muscle) contained about 0.1 ppm. These distribution studies suggest that while the lobster may protect itself from DDT toxicity by sequestering the pesticide in the hepatopancreas and in egg masses, bioconcentration in these tissue could be hazardous to species consuming these parts of the lobster.