The Living Earth Institute (LEI) in a cooperative project with Save the Children conducted with a technical analysis of pesticide pollution in Inle Lake, Myanmar. These results have been provided to the Inle Lake Preservation Project Executive Committee, which was initiated by the Myanmar government in 1997. The Executive Committee includes members from Shan State Peace and Development Council, Nyaungshwe Township local authorities, and government staff from the Irrigation, Agriculture, and Forestry Departments.
Inle Lake is the second largest lake in Myamnar (Burma). The lake serves as a major tourist attraction. The lake is impacted by many factors including pesticides from agriculture, chemical dyes from textile processing, excess siltation from watershed erosion, and the dumping of wastes and garbage. As a result, the fish (Inle Carp) serving as the main public food supply is becoming scarce. In addition, public disease rates have dramatically increased. These health problems are thought to be primarily caused by the excessive use of pesticides.
The main business of the Inle Lake region is floating garden agriculture. Tomatoes, the primary cash crop, comprise two-thirds of the region's agriculture. The remaining one-third consists of flowers, vegetables, and sugarcane plantations. The farmers routinely use pesticides and fertilizers for their crops.
The project used a water quality modeling approach to predict toxic substances in Inle Lake. The analysis modeled lake process mechanisms with lake sediment bottoms, suspended sediment, and gas exchange. The calculations, terms, state variables, and modeling assumptions are defined for each pesticide assessed. Three pesticides were identified as commonly used in tomato cultivation around Inle Lake; the insecticides monocrotophos and cypermethrin, and the fungicide metalaxyl. No herbicides were identified as being used even though their use is common for tomato crops. The loading capacities of these pesticides and an additional eight other pesticides commonly used in tomato cultivation were derived. Assessment were conducted for the insecticides endosulfan, esfenvalerate and carbaryl; the fungicides mancozeb and chlororthalonil; and the herbicides trifluralin and metribuzin.
The assessment concluded that current pesticide usage for tomato cultivation must be changed to protect the health of the residents of Inle lake Watershed. First, the amount of application needs to be reduced to acceptable rates. Cypermethrin is currently applied at 1500% of the recommended rate. Metalaxyl is currently applied at 5900% of the recommended rate. The over application of these pesticides is not only costly to the farmer, but also causes unnecessary pollution that could be impairing the health of watershed residents. Second, the amount of area certain pesticides can be applied should be controlled. For example, cypermethrin should only be applied to about 4 acres to protect human health. In addition, metalaxyl should only be applied to about 143 acres to protect human health. It is recommended that a focus to using other pesticides be approached. For example, both the insecticides carbaryl and esfenvalerate can be used at appropriate application rates on all tomato cultivation without a risk to human health.
Further details can be found in the technical document (Acrobat PDF).
Steve Butkus, Project Manager
Contact LEI: info@living-earth.org