Bioconcentration of chlorinated hydrocarbons from sediment by oligochaetes

Abstract

Previously published data on the accumulation of 15 chlorinated hydrocarbons from sediment by oligochaetes have been interpreted on the basis of bioconcentration from interstitial water. Calculation of the interstitial water concentration allowed determination of uptake and clearance rate constants together with bioconcentration factors ( K B) for these compounds. These three factors each exhibited a systematic relationship to the octanol/water partition coefficient ( K OW). The log K B versus log K OW relationship was roughly linear over the log K OW range from 4.4 to 6.4 and displayed an increasing nonlinear deviation for log K OW values > 6.4. These relationships are qualitatively similar to those established for other aquatic organisms where bioconcentration from water was the mechanism involved. This suggests that interstitial water may be the phase from which lipophilic compounds in sediment are bioconcentrated by oligochaetes. An expression relating the bioconcentration factor to the biotic concentration and various sediment characteristics has also been developed.