Studies on degradation of 14C-DDT in the marine environment

Degradation of C-14-DDT was studied in a marine ecosystem for 60 days and in marine sediments under moist and flooded conditions using a continuous now system for a period of 130 days. C-14-DDT residues were recovered in sediments of the marine ecosystem at uniform level of 60-65% of the applied C-14-activity throughout the incubation period. DDD was a major metabolite in sediments while DDMU was a major metabolite in clams. Clams brought about substantial degradation of DDT. However, C-14-residues recovered form clams are not suggestive of significant bioaccumulation. In the continuous now experiment, under both moist and flooded conditions, DDT underwent degradation and about 22% of the applied C-14-activity was recovered as volatiles under both conditions. In sediments, extractable C-14-residues accounted for about 30 and 19% under moist and flooded conditions, respectively. DDT was the major compound in extractable residues as identified by TLC-autoradiographic procedures. More bound residues were formed under flooded than under moist conditions, (C) 1999 Elsevier Science Ltd. All rights reserved.