EARTHWORM AND FOOD INTERACTIONS ON BIOACCUMULATION AND DISAPPEARANCE IN SOIL OF POLYCYCLIC AROMATIC-HYDROCARBONS - STUDIES ON PHENANTHRENE AND FLUORANTHENE

The present study describes some novel phenomena with regard to the en vironmental fate of polycyclic aromatic hydrocarbons (PAHs) in the ter restrial soil environment. Laboratory experiments were conducted on: ( 1) the influence of earthworms on the disappearance rate of PAHs in so il, and (2) the bioaccumulation of these compounds in the earthworm bo dy. It is demonstrated that the disappearance of phenanthrene and fluo ranthene in soil is accelerated by the presence of the earthworm Lumbr icus rubellus. Possible explanations and practical implications of thi s effect are discussed. In the bioaccumulation part of the study it is demonstrated that earthworms may take up and accumulate fluoranthene and, to a lesser extent, also phenanthrene in their body tissues. Bioa ccumulation was found to be reduced by changes in bioavailability asso ciated with aging of the PAH-amended soil. Finally, it was observed th at earthworms indicate a strongly enhanced bioaccumulation of PAHs und er conditions of food limitation. (C) 1995 Academic Press, Inc.