THE RADON

THE RADON

Radon is a noble gas of which three natural isotopes and several synthetic isotopes are known. All radon isotopes are disintegrated naturally, producing alpha particles.

This gas has been the object of the following groups:

1. volcanologists and seismologists for the purpose of establishing earthquake precursors;
2. geophysicists to know the structure of terrestrial crust;
3. physicians to study the radon effects on lung cancer.

Radon-222 is produced from the natural radioactive decay of radium-226, which is in turn produced by the decay of uranium-238. Due to its chemical nobility radon is not injurious for the health; but the daughter elements produced from its decay such as polonium-218, polonium-214, bismuth-214 and lead-206 are extremely injurious. At the same time, radiation produced by the alpha particule is a cause of lung cancer. The risk of developing lung cancer depends on radon concentration in the air that we breathed, as well as of the exposition time.

Radon concentration can be expressed in many different units, but is most commonly refered to as pCi/L (picoCurie per liter). The Environmental Protection Agency - EPA - of the United States of America has determined that 4 pCi/L of radon in the air is the action level (or level at which, environmental controls should be applied) and 300 pCi/L the action level of radon in drinking water. The EPA has calculated that radon exposure is the cause of 5000 to 20000 deaths of lung cancer per year in the USA. That is to say, it is the second leading cause of lung cancer deaths in the United States of America, after tobacco consumption.

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