Modeling of the residue transport of lambda cyhalothrin, cypermethrin, malathion and endosulfan in three different environmental compartments in the Philippines

This study aims to determine the environmental transport and fate of the residue of four Philippines priority chemicals; i.e., lambda cyhalothrin (L-cyhalothrin), cypermethrin, endosulfan and malathion, in three different environmental compartments (air, water and soil). In the Philippines, pesticide application is the most common method of controlling pests and weeds in rice and vegetable farming. This practice aided the agricultural industry to minimize losses and increase yield. However, indiscriminate use of pesticides resulted to adverse effects to public health and environment. Studies showed that 95% of the applied pesticides went to non-target species. Data from previous studies in Pagsanjan Laguna, Philippines were used as input data. Dispersion, Gaussian plume, and regression equations were employed to simulate the behavior of L-cyhalothrin, cypermethrin, endosulfan and malathion in air, water and soil. Substance decay was calculated using first order reaction. This study showed how L-cyhalothrin, cypermethrin, endosulfan, and malathion behaved in the environment after release from nozzle spray, and its possible duration of stay in the environment. It will also show a tool in determining the percolation depth through soil by endosulfan. This tool can be utilized in determining the depth of contaminated soil during remediation strategic planning and project implementation of similar environmental condition. (C) 2016 Chinese Institute of Environmental Engineering, Taiwan. Production and hosting by Elsevier B.V.