§16§Chemical control of rats has done using coumarion rodenticides in different formulations: Paraffin block and pellet (brodifacoum and bromadiolone, active ingredients) and powder contact (coumatetralyl, active ingredient). Paraffin block are placed in culverts, powder contact is applied in the entrance of the burrows on soil and pellet is placed indoor. These formulations are used in urban areas, but there is not information about environmental behavior of the active ingredients. This research evaluated persistence of these active ingredients in them formulations under fieldwork, during ten weeks. The results pointed the stability of brodifacoum and bromadiiolone paraffin block and pellet under fieldwork. However, there was decreased about 80% in the concentration of coumatetralyl powder contact on top soil, during environmental exposition, but this active ingredient did not leached, because it was not found in the collected rainwater.
