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Thursday, July 21, 2011

Radon: Radiation on the Home Front


It seeps up through the ground, pooling in basements and cellars. It can infiltrate our homes and even our lungs, spreading radiation with every ripple of breeze. Present in nearly every country of the world, this substance is colorless, odorless, and tasteless. It kills thousands every year and requires special equipment to locate.
Although this sounds like something from a cheesy science fiction film, radon gas is a real threat to people all over the world. Radon-related diseases cause about 21,000 deaths per year in the US1 (almost twice the number of drunk driving deaths), meaning in most countries only smoking causes more deaths from lung disease.

Deaths Per Year - Source: http://www.epa.gov/radon/pubs/citguide.html

The first reason radon is dangerous is because it’s all around us. The EPA estimates that 1 out of every 15 homes in the US has elevated radon levels2 . In almost every country radon is the largest natural source of human exposure to ionizing radiation and makes up over half the radiation each person is exposed to in a year. Since radon is a decay product of uranium, it is more often found where there are large concentrations of granite, like those occurring in Ireland and the UK, Canada, and some US states such as Iowa and Pennsylvania.  
Radon Test Kit - Source: http://visualsonline.cancer.gov
The physical properties of radon also contribute to its effect on people.  Radon is one of the most dense gases on our planet – over 8 times denser than the atmosphere at sea level. This causes it to pool at the bottom of whatever container it is in. Because of this, elevated radiation levels from radon are found in the lower levels and basements of buildings. It also means that when breathed in, radon gets trapped in the bottom of the lungs and has more potential to do damage. Radon emits mostly alpha radiation which is made up of fast-moving particles with more mass than beta or gamma radiation. Alpha radiation doesn’t penetrate very well – it can be stopped by as little as a piece of paper or human skin. So the real risk to humans from alpha radiation is when it gets inside us and starts to affect our internal organs. Because it is a gas, almost all the damage done is in the lungs and can lead to lung cancer.   
The good news about radon is that it is easily detectable and many options are available to lessen radon risks in the home. Short- and long-term radon test kits are inexpensive and commercially available throughout the world. A short-term test (which takes several days) gives the homeowner an estimate of radon concentration in the home, and a subsequent long-term test (which takes a year or more) can give a more precise measurement. There are varying ‘action levels’ of radon throughout the world, but most countries recommend taking some action to reduce radon if average concentrations are above 4 pCi per liter of air3. Solutions to lower radon concentrations include venting air from lower stories of a house or pressurizing areas to keep external gases out.
An example of radon venting from the US EPA.
Although radon may sound scary and looks pretty bad on paper, many people can significantly lower their risk of radiation exposure from radon. Good information is widely available on this subject, including the World Health Organization’s Radon Handbook and A Citizen’s Guide to Radon by the US Environmental Protection Agency.  
D-tect Systems is supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

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