Dissipation and degradation of DDT and DDE in Philippine soil under field conditions
Title:
Dissipation and degradation of DDT and DDE in Philippine soil under field conditions
Author:
Varca, L. M. Magallona, E. D.
Appeared in:
Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes
Paging:
Volume 29 (1994) nr. 1 pages 25-35
Year:
1994
Contents:
Dissipation and degradation of 14C-p,p'-DDT in soil was studied under field conditions in the Philippines for two consecutive years. Extractable radioactivity decreased with time while there was a gradual increase of bound activity. Half-life of dissipation of total 14C was 261 days and 210 for the two field trials while the half-life of extractable radioactivity was 173 and 134 days. p,p'-DDE was the major metabolite in the extracts and the half-life of extracted DDT was 105 days. In the laboratory, the soil mineralized 70% of 14C-DDT at 35°C in six weeks, while organic volatiles contributed < 1%. Almost 80% of soil-bound 14C was released by addition of fresh soil; presumably through the action of microflora. Under field conditions, 14C-DDE dissipated with a halflife of 151 days, and bound 14C residues accounted for 40% of the terminal residue after one year. The results indicate that p,p'-DDT and p,p'-DDE dissipate from Philippine soils at rates which may preclude accumulation of residues.
Journal description