Radon Gas Effect
At least trace amounts uranium is found on the soil of the entire planet and when this uranium decays, it gives off gas in the form of radon. Normally this isn't a problem, because the radon gas disperses into the atmosphere, where it's greatly outnumbered by other benign elements. But when you build a house on an area which has high radon levels, the gas cannot escape to the atmosphere. It tries to travel through the building and, depending on the insulation of the building, could take quite a while to travel. The longer the gas takes to pass through the building, the more the humans who breathe that air are at risk.
 Radon Kills
Researchers feel that radon probably kills, or helps kill, about 21,000 in the US and 20,000 in the European Union every year. Yet there is very little public awareness about this threat which can also be removed quite easily. Depending on the source, radon can be found in drinking water too.
Radon is a naturally occurring invisible, odorless, tasteless radioactive gas released from the decay of uranium in rocks and soil. It is not a result of global warming or human activities. Though you cannot see, smell or taste the gas, it, nevertheless, seeps into your home through the ground and diffuses into the air. In certain areas radon dissolves at high concentrations in ground water and when that water is used the gas gets released into the air. Though radon gas remains within permissible limits outdoors, it accumulates in areas without ventilation and can reach proportions which increase the risk of cancer. Long-term exposure leads to lung cancer.
 Radon is Radioactive
Radon decays because it is radioactive. And on decaying emits tiny radioactive particles. The human skin is too thick for these particles to penetrate, but if inhaled they can damage the cells lining the lung. Failure to notice the presence of radon gas in your home does not mean that you will drop dead or certainly fall ill. But it definitely increases the risk.
Radon concentration in a home depends on how much of uranium producing the radon is present in the underlying rocks and soils. It also depends on the routes available for its passage into the home and the rate of exchange between indoor and outdoor air.
Apart from running water radon gas enters homes through cracks and holes in building foundations. Homes which are well insulated, or built on uranium-rich soil, get the highest level of radon. As radon gas is found closer to the ground, the basement and first floors are worst affected.
 Presence Found Worldwide
Radon gas in the air is present worldwide, its concentration depending on the highly variable uranium content of the soil. In most countries there are many homes with moderate levels, and a relatively small proportion of homes with very high levels.There is, however, no safe level of radon.
As radon can be found in water and rocks too, granite countertops can be sources of radon. There was report of a school in Massachusetts that had radon pouring out of granite walls located inside the building.
The most common entry routes for radon gas to your home are:
- spaces between basement walls and slab
- cracks in foundations and/or walls
- openings around sump pumps and drains
- construction joints
- crawl spaces
- showers, etc using well water with high radon concentrations
 Radon and Smoking
Radon gas is not as big a cause for cancer as cigarette smoking, but a majority of radon-related cancer deaths are found to occur among smokers. According to a report published by the National Cancer Institute , USA, there is a 14 percent greater risk of developing lung cancer for those living 30 years in a house with a radon level of 150 Becquerels per cubic meter (Bq/m3).
A British Medical Journal study, funded by Cancer Research UK and the European Union found that though the risk of cancer to life-long non-smokers from radon exposure was low, smokers have about 25 times the risk of developing lung cancer.
 Radon Testing
Tests can determine whether your home has elevated radon levels. Each home has different radon levels, so tests in your and your neighbor’s home can show different results. Radon levels can also vary from day to day and month to month on account of precipitation, barometric pressure, and other influences. Therefore, it is advisable to conduct both short and long-term tests which are available. Short-term tests track radon levels for up to 7 days. Long-term detectors give the average concentration for periods of 90 days or more.
For short-term tests the house is kept closed for 12 hours after which the test instrument is activated and left for 48 hours or more. In long-term tests there is no need to keep the house closed though the test takes more than 91 days to complete.
 Fixing the Problem
You can fix the radon problem by installing a ventilation system (on the lines of a bathroom vent) for the whole house. It can help suck the air from the lower level of the house and disperse it outside.
Other steps you can take to reduce radon levels in your home include:
- Renovate you basement floors, particularly earth floors
- Seal all cracks and openings in walls and floors, and around pipes and drains
- Provide adequate ventilation to the sub-floor of basement floors.
- Questions and Answers About Radon and Cancer
- Radon gas linked to cancer deaths
- Minimizing the Risks of Radon in the Home
- The Radon Problem