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~~ ~ a~ ~ ~ ~ <br />~ ~ ~ ~G <br />t, .Y 'I <br />What is radon? <br />Radon is a naturally occurring, invisible, odorless gas that comes from deposits of <br />uranium in soil, rock, and water. It is harmlessly dispersed in outdoor air, but when <br />trapped in buildings, can be harmful, especially at elevated levels. Radon is a <br />radioactive decay product of radium, which is a decay product of uranium. Both <br />uranium and radium are common elements in soil. <br />Where is radon found? - <br />The primary source of high levels of radon in homes is the surrounding soil and <br />underlying rock. Radon in water is found in nearly all sources of surtace water and <br />groundwater. ,Water that flows through or over radium rich rock formations chiefly <br />found in the piedmont and mountain regions of the state, accumulate radium and-thus <br />radon from the decay process.. Groundwater usually has much higher levels than <br />surtace water because radon in groundwater is "trapped" by being submerged <br />underground and cannot easily escape. <br />How does radon get into my house? <br />Air pressure inside your home is usually lower than pressure in the soil around your <br />home's foundation.. Because of this difFerence in pressure, your house acts like a <br />vacuum, drawing radon in through foundation cracks and other openings like floor <br />drains, ductwork, and pipes. Radon may also be present in well water and can be <br />released in the air in your home when water is used for showering and other household <br />. uses. In most cases, radon entering your home through water is a small risk <br />compared with radon entering your home from the soil. <br />What are the health efFects of radon? <br />Exposure to radon is the second leading cause of lung cancer in the United States. <br />Radon can be inhaled into the lungs, where it undergoes radioactive decay. As it <br />decays, radon releases tiny bursts of energy called alpha particles, which can harm <br />sensitive lung tissue by damaging the DNA. This damaged DNA can lead to lung <br />cancer. The main type of cancer caused by radon in water is also lung cancer. This is <br />because a large, fraction of radon in water is released to the air when water is used in <br />common household tasks such as showering, washing clothes, and other uses where <br />water can become vaporized. <br />How is radon measured? <br />Radon is measured in picocuries per liter of air (pCi/L). The US Environmental <br />Protection Agency and the Centers for Disease Control and Prevention recommend that <br />homes with radon levels at or about 4 pCi/L be fixed. The "action" levels in water are <br />set much higher at 300 pCi/L. The water levels are considerably higher because it <br />takes high. levels of radon in water to produce significant levels of radon in air. The rule <br />of thumb is that it takes 10,000 pCi/L of radon in water to raise the level of radon in air <br />1 pCi/L. Using this rule, it would take 40,000 pCi/L in water to raise the indoor air <br />radon level to 4 pCi/L. <br />