Test Details & Preparation

Caesium is a naturally-occurring element found in rocks, soil, and dust at low concentrations. Granites contain an average caesium concentration of about 1 part of caesium in a million parts of granite (ppm) and sedimentary rocks contain about 4 ppm. Natural caesium is present in the environment in only one stable form.

Pure caesium metal is silvery white in colour and very soft, but pure caesium is not expected to be found in the environment. Pure caesium metal reacts violently with air and water, resulting in an explosion-like reaction. Caesium compounds do not react violently with air or water and are generally very soluble in water. The most important source of commercial caesium is a mineral known as pollucite.

You can be exposed to stable or radioactive caesium by breathing air, drinking water, or eating food containing caesium. The level of caesium in air and water is generally very low. The concentration of natural caesium in air is generally less than 1 nanogram. The amount of caesium in drinking water is ordinarily about 1 microgram per litre of water.

Radioactive caesium has been detected in surface water and in many types of food. This includes breast milk and pasteurized milk. The amount of radioactive caesium in food and milk is highly dependent upon several factors. The most important factor is whether or not there has been recent fallout from a nuclear explosion such as a weapons test or an accident that has occurred at a nuclear power plant.

Stable and radioactive caesium can enter your body from the food you eat or the water you drink, from the air you breathe, or from contact with your skin. When you eat, drink, breathe, or touch things containing caesium compounds that can easily be dissolved in water, caesium enters your blood and is carried to all parts of your body. Caesium is like potassium it enters cells and helps to maintain a balance of electrical charges between the inside and the outside of cells so that cells can perform tasks that depend on those electrical charges.

Everyone has small amounts of caesium in their body. Laboratories use special techniques to measure the amount of caesium in body fluids such as blood and urine, as well as in faeces or other human samples. This can give an indication of whether a person has been exposed to levels of caesium that are higher than those normally found in food, water, or air. Special radiation detectors can be used to detect if a person has absorbed radioactive caesium. It is difficult to determine if a person has been exposed only to external radiation from radioactive caesium. Health professionals examining people who have health problems similar to those resulting from radiation exposure would need to rely on additional information, such as the testing of blood samples for cell counts and chromosomal damage, in order to establish if such people had been affected by being near a source of radioactivity.