For the Scientifically Minded

Radon is a cancer causing radioactive gas that is caused by naturally radioactive breakdown of particles of uranium in the soil, rock and water. 
               
                Decay Chain Uranium to Radon
                                 Type of Radiation                       Half Life

	Uranium 238	Alpha	4.47 billion years
	Thorium 234	Beta Gamma	24.1 days
	Protactinum 234	Beta Gamma	1 minute
	Uranium 234	Alpha Gamma	245,000 years
	Thorium 230	Alpha Gamma	76,000 years
	Radium 226	Alpha Gamma	1600 years
	Radon 222	Alpha	3.8 days

Radon Gas is a class 1 carcinogen: that means it causes cancer in humans.

Health Canada’s web site

Because Radon Gas is a noble gas it does not bond well with other particles. It begins to move through the soil seeking places of lower pressure/concentration. It normally escapes to the air and is found naturally all over the world. When found outdoors, it is treated as background radiation. When it seeps into a home (an area of lower pressure than the soil around it) it can collect in much higher quantities and become dangerous to the occupants of that home.

The Radon decay chain has a group of highly radioactive (short half life) daughters. The radiation given off while inside the lungs is the reason why Radon Gas causes lung cancer.  

Decay chain of Radon to Lead

	Radon 222	Alpha	3.8 days
	Polonium 218	Alpha	3 minutes
	Lead 214	Beta Gamma	27 minutes
	Bismuth 214	Beta Gamma	20 minutes
	Lead 210	Beta Gamma	22 years
	Pulonium 210	Alpha	5 days
	Lead 206	Stable	138 days

When Radon decay products are inhaled they stick to sensitive lung tissue.  Being short-lived, they break down while they are in the lungs.  This exposes the lung tissue to radiation.

This is an excerpt from Uranium: a Discussion Guide. Published by Canadian Coalition for Nuclear Responsibility

Is Radioactivity Dangerous?

Alpha particles, beta particles and gamma rays can do great harm to a living cell by breaking its chemical bonds at random and disrupting the cell's genetic instructions.
Massive exposure to atomic radiation can cause death within a few days or weeks. Smaller doses can cause burns, loss of hair, nausea, loss of fertility and pronounced changes in the blood. Still smaller doses, too small to cause any immediate visible damage, can result in cancer or leukemia in the person exposed, congenital abnormalities in his or her children (including physical deformities, diseases and mental retardation), and possible genetic defects in future generations.
Outside the body, alpha emitters are the least harmful, and gamma emitters are more dangerous than beta emitters.
Inside the body, however, alpha emitters are the most dangerous. They are about 20 times more damaging than beta emitters or gamma emitters. Thus, although alpha radiation cannot penetrate through a sheet of paper or a dead layer of skin, alpha emitters are extremely hazardous when taken into the body by inhalation or ingestion, or through a cut or open sore.
How do radioactive elements produce other radioactive elements?
When atoms undergo radioactive decay, they change into new substances, because they have lost something of themselves. These by-products of radioactive decay are called "decay products" or "progeny". In many cases, the decay products are also radioactive. If so, they too will disintegrate, producing even more decay products and giving off even more atomic radiation.’

Knowing this, are you willing to take the risk?

The only way to know what your exposure is, is to test your home.