Contamination of soil is very common at landfill sites and toxicity by various metals is the most persistent. The leachate that is found in the ground water and the surrounding water has found to be very toxic.

The common metals found to cause these problems are, copper, lead, nickel, zinc and cadmium.

The above metals and a few more have found to be in the tissue of some animals and humans which causes liver problems and brain dysfunctions.