Distribution and fate of 14C-DDT in the estuarine environment of the north of Viet Nam

The distribution and fate of DDT in various environmental compartments have been studied using 14C techniques in a microcosm simulating the marine environment conditions of the north of Viet Nam. It was shown that up to 95-96% of the initial amount of 14C-DDT was deposited on sediment 72 hours after application. After 1 month, the bound form of the insecticide in sediment did not exceed 0.1-0.2%. All the 14C-DDT was deposited at the 0.5 cm layer beneath the sediment surface. Accumulation of 14C-DDT in algae raised in the microcosm was about 2% of the total amount 1-2 days after application. Accumulation of 14C-DDT in shrimp muscle was 1.2-1.5% of the initial activity 2-3 days after application. One week after application, 80 and 12% of the 14C-DDT recovered in sediment were found in DDT and its DDD metabolite, respectively. At the same time, not only DDT, but also its DDD and DDE metabolites were observed in shrimp muscle. However, the DDD and DDE contents were less than 20% compared with the total activity. (author). 6 refs, 5 tabs