Dieldrin at low levels may still be present in soil in areas where it was used as a pesticide.
It may also be attached to dust particles. Dieldrin does not dissolve in water very well and was therefore not found in water at high concentrations.
When dieldrin was used in agriculture, the main route of exposure occurred by eating contaminated food, including root crops, dairy products and meat. People who live in homes that were treated for termites using dieldrin may also have potentially been exposed.
Because of the way dieldrin breaks down and the length of time since it was last used, the amount of dieldrin still present in the environment has significantly reduced since 1987.