Change of Residual Deltamethrin Sprayed in the Stream Water according to Wind Speed and Diffusion

The objectives of this study were to provide the basic data of the residue of deltamethrin in the stream water. Deltamethrin was treated on side of Ban-Suk stream and Juk-Dong ditch for hygienic purpose by air spray. The drift concentration of deltamethrin was investigated with different wind speed condition on Ban-Suk stream (A), and the change of residue with time course on Juck-dong ford (B). Also we found the residual change of deltamethrin until 48 hour in Yu-Seong stream confluence (C) where two streams join. Maximum residues of A were (5 min, 200 m) at strong wind speed and (0 min, 25 m) at moderate wind speed according to different wind velocity. Residues of B were (0~480 min) after spraying, and decreased to a non-detected level after 720 min. Residues of C were (0 min), (1 min) and (12 hr) after spraying, and no residues were detected in any other samples. From these results, it is concluded that deltamethrin residues in water should be rapidly diluted into stream water and affected negligible toxic effect to stream ecosystem.