The highest levels of these compounds are found in some soils, sediments and animals. Very low levels are found in water and air. Extensive stores of waste industrial oils with high levels of dioxins exist throughout the world. Long term storage of this material may result in dioxin release into the environment and the contamination of human and animal food supplies. Dioxins are not easily disposed of without contamination of the environment and human populations.
Incineration is the best available answer although other methods are being investigated.
High levels of dioxins were reported to have been found in poultry and eggs in Belgium. The cause of the contamination is thought to have been animal feed. Agent Orange used during the Vietnam War. TCDD was also studied in a serious accident at a chemical factory in Seveso, Italy in 1976. A cloud of toxic chemicals, including dioxins was released into the air and eventually contaminated an area of 15 square kilometres with a population of 37,000 people.