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

Degradation of C-14-DDT was studied in a marine ecosystem for 60 days and i n marine sediments under moist and flooded conditions using a continuous no w system for a period of 130 days. C-14-DDT residues were recovered in sedi ments of the marine ecosystem at uniform level of 60-65% of the applied C-1 4-activity throughout the incubation period. DDD was a major metabolite in sediments while DDMU was a major metabolite in clams. Clams brought about s ubstantial degradation of DDT. However, C-14-residues recovered form clams are not suggestive of significant bioaccumulation. In the continuous now ex periment, under both moist and flooded conditions, DDT underwent degradatio n and about 22% of the applied C-14-activity was recovered as volatiles und er both conditions. In sediments, extractable C-14-residues accounted for a bout 30 and 19% under moist and flooded conditions, respectively. DDT was t he major compound in extractable residues as identified by TLC-autoradiogra phic procedures. More bound residues were formed under flooded than under m oist conditions, (C) 1999 Elsevier Science Ltd. All rights reserved.