ABSTRACT
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Pesticides in Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Behavior in Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 Residue in Soil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Adsorption and Leaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Degradation in Soil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Pesticides in Aquatic Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 Runoff from Farmland to Aquatic Environment . . . . . . . . . . . . . . . . 280 Degradation in Aqueous Environment . . . . . . . . . . . . . . . . . . . . . . . . 283
Pesticides in the Atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Entry Pathways into the Atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . 285
Drift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Wind Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Volatilization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Behavior of Pesticides in the Atmosphere . . . . . . . . . . . . . . . . . . . . . 287 Deposition of Pesticides with Rainfall and as Dust. . . . . . . . . . . . . . 287 Degradation of Pesticides in the Atmosphere . . . . . . . . . . . . . . . . . . 287
Influences of Pesticides on Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Impacts on Nontarget Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 Bioconcentration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
INTRODUCTION
Pesticides play a major role in controlling insect pests and weeds and have brought about sustained high yields and higher quality of agricultural produce. They have also helped liberate farmers from the backbreaking task of weeding. Pesticides, which serve purposes including those of insecticides, fungicides, and herbicides, are active substances that have some sort of toxicity toward living things. Pesticides applied to farmland are put into the environment on purpose then are dispersed widely throughout the atmosphere, soil, and aquatic environment outside farmland. Thus, in an attempt to solve problems involving toxicity, residual tendency, and selectivity among organisms, which are drawbacks of pesticides, improvements have been made in the chemical structures of these chemicals and in the ways they are formulated and applied. As a result, currently used pesticides are compounds characterized by low toxicity, easy degradability, high selectivity, and high activity (Takagi and Ueji, 1997). Decreasing the environmental load caused by pesticides is also needed to further expedite ecological farming practices.
