<strong> <a href="http://careandhealed.com/2010/04/7-steps-of-radon-prevention-strategies-part-1/">7 Steps of Radon Prevention Strategies (Part 1)</a></strong><p><span class="rdetector_placeholder_before"></span> <div align="left" style="border: 2px dashed #C2C2C2;padding: 6px;background: #FFFFFF;padding:10px;"> <h3> <ul> <li>Epidemiological studies confirm that radon in homes increases the risk of lung cancer in the general population. Other health effects of radon have not consistently been demonstrated.</li> <li>The proportion of all lung cancers linked to radon is estimated to lie between 3% and 14%, depending on the average radon concentration in the country and on the method of calculation. </li> <li>Radon is the second most important cause of lung cancer after smoking in many countries. Radon is much more likely to cause lung cancer in people who smoke, or who have smoked in the past, than in lifelong non-smokers. However, it is the primary cause of lung cancer among people who have never smoked. </li> <li>There is no known threshold concentration below which radon exposure presents no risk. Even low concentrations of radon can result in a small increase in the risk of lung cancer. </li> <li>The majority of radon-induced lung cancers are caused by low and moderate radon concentrations rather than by high radon concentrations, because in general less people are exposed to high indoor radon concentrations.</li> </ul> </h3> </div> <div style="padding:1.2em;background-color:#HEX_HERE;line-height:1.4;"> I hope you still remember this article <a href="http://careandhealed.com/2010/04/searching-for-the-cracks-in-the-wall/">Radon, Searching For The Crack In The Wall.</a> It emphasized on how important to seal the crack. But, it’s not the only thing you have to concern. Most prevention strategies address steps to limit soil gas infiltration due to air pressure differences between the soil and the indoor occupied space. Radon prevention strategies should consider the specific mix of construction practices, radon sources, and transport mechanisms in the region or country, in order to be cost-effective. Under certain conditions a combination of strategies may be necessary such as in buildings with multiple types of foundations. Several prevention strategies are summarized and listed here :</p> <p style="height:1.4em;"> </p> <h2>A. Active Soil Depressurization (ASD)</h2> <p>ASD may be a favoured option for home builders. It has a rich history, beginning with its initial experimental applications in Canada (<em>Scott 1979, Gessall and Lowder 1980, DSMA ATCON 1982</em>). Commonly, ASD systems include the following basic components : </p> <ul> <li>home and connected to a continuous and uniform permeable aggregate layer, ground water control system, or a sump; </li> <li>for human exposure, for example above the highest roof. There is evidence that ASD discharges at ground level create a risk of radon re-entering the house (Henschel and Scott 1991, Yull 1994, Henschel 1995). Therefore, even if the risk appears to be small, ASD systems should be installed in a way that minimizes this risk; </li> <li>conditioned space of the home. An important distinction between ASD in existing homes and new construction is that, in the latter, the use of a permeable layer and sealing provide the opportunity to use smaller, more energy-efficient fans; </li> <li>performance such as pressure differences in the vent pipe below the fan; </li> <li>with the plumbing system (similar to PSD). </li> </ul> <p><a class="highslide" onclick="return hs.expand(this)" href="http://careandhealed.com/wp-content/uploads/2010/04/Figure_4.png"><br /> <img class="aligncenter" src="http://careandhealed.com/wp-content/uploads/2010/04/Figure_4.png" title="Active Soil Depressurization (ASD)" alt="Active Soil Depressurization (ASD)" width="250" height="250"/></a></p> <h2>B. Passive Soil Depressurization (PSD)</h2> <p>PSD is used in new construction. It is similar to active soil depressurization (ASD), with the following exceptions: </p> <ul> <li>the vent pipe and its ability to slightly depressurize the soil under the dwelling. To make it effective the following should be considered: <ul> <li> the system must have a uniform permeable layer under all elements with direct contact to the ground (e.g. concrete slabs, crawlspace membranes); </li> <li>the vent pipe must be routed mainly through the heated portion of the building and any sections of the vent pipe in unheated areas must be insulated; </li> <li>the vent pipe routing must allow the easy installation of a fan if the PSD system fails to achieve sufficient radon reduction; </li> <li>the exhaust duct must discharge above the highest roof; </li> <li>the systems should be labeled at every accessible level to avoid confusion with the plumbing system; </li> </ul> </li> <li>sealed to prevent soil gas infiltration; </li> <li>the occupied area, the only way to monitor system performance is via periodic or continuous radon monitoring.</li> </ul> <p>In new construction, PSD appears to reduce radon by about 50% (Dewey and Nowak 1994). If the PSD system is properly designed and installed, small fans (e.g. 75 W or less) may be used to activate the system (Saum 1991, ASTM 2007). The use of a smaller fan saves energy-related operating costs.</p> <p><a class="highslide" onclick="return hs.expand(this)" href="http://careandhealed.com/wp-content/uploads/2010/04/Figure_5.png"><br /> <img class="aligncenter" src="http://careandhealed.com/wp-content/uploads/2010/04/Figure_5.png" title="Passive Soil Depressurization (PSD)" alt="Passive Soil Depressurization (PSD)" width="250" height="250"/></a></p> <p>(continue to <a href="http://careandhealed.com/2010/04/7-steps-of-radon-prevention-strategies-part-2"><strong>7 Steps of Radon Prevention Strategies – Part 2</strong></a>) </p> </div> <input type="hidden" id="rdetector_data" value="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" name="rdetector_data" /><span class="rdetector_placeholder_after"></span></p> <p>Related posts:</p><ol><li><a href='http://careandhealed.com/2010/04/7-steps-of-radon-prevention-strategies-part-2/' rel='bookmark' title='Permanent Link: 7 Steps of Radon Prevention Strategies (Part 2)'>7 Steps of Radon Prevention Strategies (Part 2)</a></li> <li><a href='http://careandhealed.com/2010/04/searching-for-the-cracks-in-the-wall/' rel='bookmark' title='Permanent Link: Radon, Searching For The Cracks In The Wall'>Radon, Searching For The Cracks In The Wall</a></li> <li><a href='http://careandhealed.com/2010/04/why-is-there-radon-in-my-house/' rel='bookmark' title='Permanent Link: Why Is There Radon In My House? Where Does This Thing Come From?'>Why Is There Radon In My House? Where Does This Thing Come From?</a></li> </ol><br> <div style="border: 2px dashed #C2C2C2;padding: 3px;background: #FFFFFF;padding:7px;"> This article is published by <a href="http://careandhealed.com">http://careandhealed.com</a>. You are permitted to republished this article by giving credit to the link source.</div>