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Unformatted text preview: h measured an extremely high level of radioactivity in the basement air. The air in his home
contained an isotope of radon. Radon-222 atoms undergo radioactive decay by emitting alpha particles. Radon is
always associated with uranium deposits. Some uranium occurs naturally in most soils and rocks in widely
varying amounts. Radon-222 has a half-life of 3.8 days. This gives it time to migrate up out of the ground and
to enter buildings through cracks in foundations. It can also dissolve in ground water and enter a home via well
The element radon has been known since its discovery in 1900. As a member of the noble gas group of
elements, radon is a colorless, odorless, and tasteless gas with very little tendency to combine with other
elements. Therefore, it tends to stay in the air. Radon atoms in the air can be inhaled into the lungs. If radon
atoms decay in the lungs, we get a dose of radiation. In addition, its decay products, particularly polonium-218
and polonium-214, are deposited in the lungs. These isotopes are radioactive and contribute more to the radiation
dose than that received from radon itself. These alpha-emitting isotopes are of the greatest health concern because
they are solids and become trapped in respiratory passages. Here their radioactivity can damage nearby cells,
which over a long period of time leads to lung cancer. In order to better assess the danger to people, health
workers are trying to sort out the importance of the three main causes of lung cancer: cigarette smoking,
secondary smoke, and radon gas. EXERCISES
18. What is the formula for radon gas? To what group of elements does it belong?
19. Radon decays into two extremely dangerous radioisotopes. What are they?
20. What is the principle health effect of radon gas?
_______________________________________________________________________________ CONCEPTUAL QUESTIONS
2. Back Ozone occurs naturally in the atmosphere; so is it correct to call it a pollutant?
Is it more feasible to try to reduce the effects of acid rain by reducing SO2 emissions from po...
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This note was uploaded on 09/15/2009 for the course CHEM 102 taught by Professor Bastos during the Spring '08 term at Adelphi.
- Spring '08