Plutonium

Plutonium (symbol: Pu) is a transuranic chemical element with the atomic number 94. All isotopes are alpha emitters. In nature Plutonium usually can't be found - or only in traces.

Plutonium is one of the most toxic substances. So far it was released with the atomic bomb on Nagasaki and by several nuclear accidents like Mayak and Chernobyl. The above-ground nuclear weapons tests spread 4 t of plutonium worldwide. After a release particle of it can be incorporated with dust, water and food.

It accumulates in bone marrow and liver. Inhalation leads to lung cancer. The incorporation of as less as a few thousandth gram causes lethal radiation injuries.

Plutonium also is highly toxic as a heavy metal, and particularly harmful for the kidneys.

Plutonium-238
It has a half-life of 87.7 years.

Plutonium-239
It has a half-life of 24,110 years, while the biological half-life is 100 years in bones and 40 years in liver. Many people living close to nuclear weapons factories had been contaminated by plutonium-239.

Plutonium-240
It has a half-life of 6,564 years.