Dieldrin is a manufactured ‘organochlorine’ insecticide that was used worldwide in agriculture to protect crops from insect pests. It was also an effective control for termites in houses.
Dieldrin works by interfering with the central nervous system of insects. It is toxic to aquatic organisms and other wildlife and accumulates in the environment.
Dieldrin sticks to soil and breaks down slowly. The levels in soil reduce by half approximately every 5 to 7 years. Dieldrin was prohibited for use and sale in Victoria in 1987.