Degradation and fate of 14C-DDT and 14C-DDE in Egyptian soil
Abstract The dissipation and degradation of 14C‐DDT and 14C‐DDE in Egyptian soil were studied under field conditions. Both chemicals dissipated readily from soil; DDE, at a slightly higher rate. The time required for 50% initial dissipation of radiocarbon was estimated to be 55 and 50 days for DDT and DDE respectively. After 9 months, the organic extracts of a 14 cm soil column showed the absence of DDT from 14C‐DDT treated soils. In 14C‐DDE treated soils, extractable residues showed the presence of unchanged DDE as the main component. Throughout the experiment, binding from both chemicals was low (about 2%). The distribution of radiocarbon following soil incubation with 14C‐DDT or 14C‐DDE in sunlight was determined using quartz tubes. Both compounds were found to be mineralized at a low rate. Within 90 days, the percentage of mineralization was 3 and 2.2% of the applied dose for DDT and DDE, respectively. The maximum binding was 9 and 14.5% for DDT and DDE respectively. In the DDT Experiment, the amount ...