Jumaat, 28 September 2007

RADON

Should I test my home for radon?
Yes! Radon is a known human carcinogen and the second leading cause of lung cancer in the U.S. Since radon is a colorless and odorless gas, the only way to know for sure how much you and your family are exposed to in your home is to test. Testing for radon is easy and inexpensive.

How do I test for radon in my home?

It's easy. You can either do it yourself or hire a home measurement service. If you do it yourself, test kits can be purchased at retail outlets or directly from laboratories providing radon measurement services. Follow the instructions that come with your test kit. The test kit should be placed in the lowest lived-in space in your home (the basement if it is frequently occupied, otherwise the first floor). You should place the kit at least 20 inches above the floor and away from exterior walls. Indoor radon levels can be elevated by unusually high winds and storms so avoid testing during these periods. Be sure to send your radon kit to the lab specified on the package right away for the most accurate results. You should receive your test results in a few weeks. For a list of certified home measurement service providers, contact your State Radon Program or see the Region 10 website for a list of labs (link to PDF)

What do my radon test results mean?

Radon is measured in picocuries per liter of air (pCi/L). The average indoor radon level in homes across the country is about 1.3 pCi/L. The average outdoor radon level is about 0.4 pCi/L. Exposure to radon increases the risk of lung cancer incidence; the higher the concentration, the higher the risk. EPA recommends taking action against radon at levels of 4 pCi/L and higher.

What do I do if my radon test results are 4 pCi/L or higher?

Test again to confirm these results. EPA recommends that, if your initial short-term test results are 4 pCi/L or higher, you consider performing a second test to verify the results. The higher your initial short-term test results are, the more reason you have to choose a short-term follow-up test over a longer-term follow-up test. If your second round of test results are still at or above 4 pCi/L, EPA recommends taking action against radon.

How do I take action against radon in my home?

No. Radon comes from the natural decay of uranium in the soil. Even though the amount of radon in the soil might be similar throughout a neighborhood, the amount of radon that actually gets into your house may differ from the amount that gets into your neighbor's house. Radon enters your home through cracks, joints and pipe penetrations in the foundation and walls, exposed soil (like in a crawl space), water and building materials. Radon levels in your home are also affected by ventilation, pressure differences and temperature differences with the outside air. Since all houses are built a little differently, they can have very different indoor radon concentrations, despite similar soil concentrations. Nearly 1 in 15 homes in the U.S. is estimated to have elevated radon levels. Again, the only way to know for sure what the radon levels are in your home is to test.

Should I worry about radon in my water supply?

In comparison to radon that enters your house from the soil, radon that enters your house from water is, in most situations, a small source of risk. A general rule-of-thumb is every 10,000 pCi/L of radon in the water supply will cause an incremental increase of 1 pCi/L of radon in the indoor air. Radon in water can enter your home only through groundwater supplies that come directly from wells. Water treatment and storage at public water supplies typically result in very low radon concentrations entering the distribution system. Therefore, Region 8 recommends testing of all private well water supplies concurrent with an indoor air radon test. If your water supply comes from a private well, you can contact a certified testing lab to have your water tested for radon.

What is the BIER VI report by the National Academy of Sciences?

The NAS has prepared its latest analysis of health research on radon, the Biological Effects of Ionizing Radiation (BEIR VI) Report. This is the most comprehensive review effort to

date. The Committee was charged with:

reviewing all current miner and residential data, as well as all existing cellular-biological data,

comparing the dose per unit exposure effects of radon in mines and homes,

examining interactions between radon exposure and smoking, and

Examining any exposure-rate effect (alteration of effect by intensity of exposure). The report confirms that radon is the second leading cause of lung cancer in the U.S. and that it is a serious public health problem. The study fully supports EPA estimates that radon causes about 15,000 lung cancer deaths per year. You can read a summary of the report at http://www.epa.gov/iaq/radon/beirvi.html

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