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Bill Brodhead WPB Enterprises Inc
Radon & Vapor Intrusion |
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Bill Brodhead WPB Enterprises Inc.
Radon & Vapor Intrusion |
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You can ask Bill any question by email: Bill's email |
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You can ask Bill any question by email: Bill's email |
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Questions & Answers |
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(These are solid particles) (Half life) Uranium 238 4.5 billion yrs Thorium 234 24 days Protactinium 234 1 minute Uranium 234 1/4 million yrs Thorium 230 80,000 yrs Radium 226 1620 yrs |
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The next element after Radium 226 is RADON. See the decay series listed below. Radon is the only noble gas in the final decay chain. Noble gases have no charge (non-reactive) which means radon can freely move through the soil. Radon's half life is about 4 days, which is just enough time to float through the soil, get into our homes and decay into a series of short lived charged particles that can get lodged in our lungs and damage the lung cells. |
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(Noble gas) (Half life) RADON 222 3.8 days (These are solid particles) Polonium 218 3 minutes Lead 214 27 minutes Bismuth 214 19 minutes Polonium 214 0.0016 seconds Lead 210 22 yrs Bismuth 210 5 days Polonium 21 128 days Lead 206 Stable |
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Is Radon's connection with Lung Cancer scientifically valid?Every scientific group that has carefully looked at the available data has agreed that there is a connection between radon exposure and lung cancer. Radon has a Class A carcinogen rating because there is so much human data, animal studies and sound explanation of how it takes place. See actual scientific papers at: Health Risk Page |
Should you be concerned about Granite Countertops?Bill presented a paper on measuring radon from granite countertops at the 2008 International Radon Conference. His measurements indicated it would only be in very rare cases that radon would be significantly elevated in a home from granite tile or granite countertops. Visit his more detailed Granite & Radon information page. |
How many homes in my area have elevated radon?The EPA has radon maps that show what the general risk of radon is in each county of each state. EPA Zone maps Air Chek, one of the largest radon test kit suppliers in the country provides a graph of how many homes in a state have elevated radon levels. Air Chek state radon levels Regional 3 EPA, which covers Pennsylvania, has state maps with radon levels broken down by zip code. Region 3 zip code maps The PA DEP provides the highest and average radon level for each zip code in Pennsylvania. PA DEP zip code data WPB has individual maps of every county in Pennsylvania with each zip code color coded by percentage of homes with radon levels above the guideline. PA radon levels by zip code |
Should I test radon in water?The EPA states in the Home Buyers and Sellers guide to radon "If you have tested the air in your home and found a radon problem, and your water comes from a well, have the water tested.' Radon in water needs to be in the thousands to be a significant risk. One study indicated that about 1 in 20 wells in Pennsylvania will have radon levels of 3000 pCi/l or higher. For more information refer to the radon in water information page here |
Can a home seller beat a radon test (cause it to pass)?Radon levels will change when you open a window especially if the window is in the same area as the test kit. In general however the window or multiple windows have to be wide open in the test area to make a big change (cut radon levels in half). Opening windows can bring marginal radon levels below the guideline. Opening windows on floors above the area being tested can cause the radon levels to go either higher or lower. Moving the radon detector to a low radon area will obviously also change the results to the new location level but many testers will minimize this possibility with tamper resistant features. We have a full report on test tampering available as a download. Whether you believe radon is over-hyped or not, the EPA risk table graphically illustrates that the exposure risk to radon is very serious. Lung cancer is the most deadly of all cancers. No one should ever knowingly tamper with a radon test that might end up subjecting someone to a high risk of contracting lung cancer. |
How does a radon mitigation system work?The most common radon system is a sub-slab depressurization system. A fan, located in an attic or outside the building, is used to draw air out from under a basement, crawl space or slab on grade concrete slab. If done properly, the entire area directly below the slab becomes negative in pressure as compared to the air above the slab. This causes the normal airflow out of the soil to reverse and flow into the soil, which effectively stops all infiltration of radon laden soil gas. The sub-slab depressurization system needs to create this sub-slab negative pressure under all slabs that are contributing a significant amount of radon into the building. Refer to mitigation system explanation for a more detailed description and system drawings. Check out mitigation system photosor see a mitigation system installation sequence. |
Must the fan be outside or in the attic & vented above the roof line?Active soil depressurization (ASD) must be vent above the roof line because the radon levels in the exhaust are often thousands of pCi/L. Sometimes it is possible to route piping from the basement up through a closet(s) to the house attic or through the garage to the garage attic. The fan can be installed in the attic and the exhaust would be routed above the roof by using a plumbing flashing through the shingles. Sometimes on the outside we use downspout piping to minimize system appearance. See Job Photos or mitigation system installation sequence. The radon fan cannot be installed in the basement. The fan must be outside or in the attic. |
Can a Homeowner install a radon mitigation system?
In Pennsylvania the
following items are required by state law. A homeowner however can always install his own mitigation system. I recommend you visit Infiltec to obtain your mitigation supplies and general installation information if you wish to tackle the job yourself. |
How low will radon levels be after installing a radon system?85% of our post mitigation test results are less than 2.0 pCi/l. The remaining systems are between 2.0 and 3.8 pCi/l. |
What fan should be used for a radon mitigation system installation?Radon fans are often oversized for the requirements. A larger fan will not necessarily produce lower radon levels. Homes that have a gravel base under the slab can often use a very efficient 20 watt fan especially if the slab cracks can be sealed. Homes that do not have a gravel base under the slab often require a 70 watt fan. 125 watt fans are used with homes where the mitigation systems will require high airflow or stronger vacuum to overcome the resistance of pulling air through compacted soil under the slab. If a mitigation system needs to move a lot of air the size of the pipe is more important than the strength of the fan. 3" pipe moves up to 80 cfm while 4" pipe moves up to 150 cfm. Visit fan data and fan sizing information. |
Can you reduce loud radon fan vibration or airflow pipe noise?The systems noise is probably due to fan vibration transfer back though building materials rather than the actual fan noise. If the fan is very noisy it could be the fan bearings have gone bad. The fan may also be oversized for the system requirements and a more energy efficient and quieter fan can be installed. System vibration transfer can sometimes be corrected by adjusting or eliminating non essential support straps or brackets. Air flow noise in the pipes can be reduced by wrapping the pipe with an insulating material if the pipe can be accessed. See System Noise Information page for more information. If the system exhaust noise is bothersome, a muffler installed close to or at the exhaust point will help. |
Does a radon system reduce basement humidity or mold?A sizable percentage of the humidity in a basement is from soil gas infiltration. A sub-slab depressurization system stops not only radon but also moist soil gas entry. Customers often report that their de-humidifier in the basement runs less and the basement smells less moldy. A de-humidifier may still be necessary to eliminate other sources of moisture. Jump to Reducing Basement Moisture for lots of additional information. |
What is Thoron?Thoron is another naturally occurring radioactive noble gas that is can enter our homes from the soil or be present in building materials (most commonly via stone foundations). Thoron also decays into solid reactive particles that emit alpha energy and can be a health risk. Thoron however has a very short half life of 55 seconds. This typically does not allow enough time for thoron to enter the air in our homes before it decays and sticks to the soil it is produced in. Read more at Making Thoron Measurements. |
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Download a copy of the above information: Radon FAQ Questions You can ask Bill any question by email: wmbrodhead at gmail.com |
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Questions & Answers |
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(All are solid particles)
Uranium 238
Thorium 234
Protactinium 234 (half life)
Uranium 234
Thorium 230
Radium 226 |
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The next element after Radium 226 is RADON. See the decay series listed below. Radon is the only noble gas in the final decay chain. Noble gases have no charge (non-reactive) which means radon can freely move through the soil. Radon's half life is about 4 days, which is just enough time to float through the soil, get into our homes and decay into a series of short lived charged particles that can get lodged in our lungs and damage the lung cells. |
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(Noble gas)
RADON 222 (Remaining are all solids)
Polonium 218
Lead 214
Bismuth 214
Polonium 214
Lead 210
Bismuth 210
Polonium 21
Lead 206 |
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Is Radon's connection with Lung Cancer scientifically valid?Every scientific group that has carefully looked at the available data has agreed that there is a connection between radon exposure and lung cancer. Radon has a Class A carcinogen rating because there is so much human data, animal studies and sound explanation of how it takes place. See actual scientific papers at: Health Risk Page |
Should you be concerned about Granite Countertops?Bill presented a paper on measuring radon from granite countertops at the 2008 International Radon Conference. His measurements indicated it would only be in very rare cases that radon would be significantly elevated in a home from granite tile or granite countertops. Visit his more detailed Granite & Radon information page. |
How many homes in my area have elevated radon?The EPA has radon maps that show what the general risk of radon is in each county of each state. EPA Zone maps Air Chek, one of the largest radon test kit suppliers in the country provides a graph of how many homes in a state have elevated radon levels. Air Chek state radon levels Regional 3 EPA, which covers Pennsylvania, has state maps with radon levels broken down by zip code. Region 3 zip code maps The PA DEP provides the highest and average radon level for each zip code in Pennsylvania. PA DEP zip code data WPB has individual maps of every county in Pennsylvania with each zip code color coded by percentage of homes with radon levels above the guideline. PA radon levels by zip code |
Should I test radon in water?The EPA states in the Home Buyers and Sellers guide to radon "If you have tested the air in your home and found a radon problem, and your water comes from a well, have the water tested.' Radon in water needs to be in the thousands to be a significant risk. One study indicated that about 1 in 20 wells in Pennsylvania will have radon levels of 3000 pCi/l or higher. For more information refer to the radon in water information page here |
Can a home seller beat a radon test (cause it to pass)?Radon levels will change when you open a window especially if the window is in the same area as the test kit. In general however the window or multiple windows have to be wide open in the test area to make a big change (cut radon levels in half). Opening windows can bring marginal radon levels below the guideline. Opening windows on floors above the area being tested can cause the radon levels to go either higher or lower. Moving the radon detector to a low radon area will obviously also change the results to the new location level but many testers will minimize this possibility with tamper resistant features. We have a full report on test tampering available as a download. Whether you believe radon is over-hyped or not, the EPA risk table graphically illustrates that the exposure risk to radon is very serious. Lung cancer is the most deadly of all cancers. No one should ever knowingly tamper with a radon test that might end up subjecting someone to a high risk of contracting lung cancer. |
How does a radon mitigation system work?The most common radon system is a sub-slab depressurization system. A fan, located in an attic or outside the building, is used to draw air out from under a basement, crawl space or slab on grade concrete slab. If done properly, the entire area directly below the slab becomes negative in pressure as compared to the air above the slab. This causes the normal airflow out of the soil to reverse and flow into the soil, which effectively stops all infiltration of radon laden soil gas. The sub-slab depressurization system needs to create this sub-slab negative pressure under all slabs that are contributing a significant amount of radon into the building. Refer to mitigation system explanation for a more detailed description and system drawings. Check out mitigation system photosor see a mitigation system installation sequence. |
Must the fan be outside or in the attic & vented above the roof line?Active soil depressurization (ASD) must be vent above the roof line because the radon levels in the exhaust are often thousands of pCi/L. Sometimes it is possible to route piping from the basement up through a closet(s) to the house attic or through the garage to the garage attic. The fan can be installed in the attic and the exhaust would be routed above the roof by using a plumbing flashing through the shingles. Sometimes on the outside we use downspout piping to minimize system appearance. See Job Photos or mitigation system installation sequence. The radon fan cannot be installed in the basement. The fan must be outside or in the attic. |
Can a Homeowner install a radon mitigation system?
In Pennsylvania the
following items are required by state law. A homeowner however can always install his own mitigation system. I recommend you visit Infiltec to obtain your mitigation supplies and general installation information if you wish to tackle the job yourself. |
How low will radon levels be after installing a radon system?85% of our post mitigation test results are less than 2.0 pCi/l. The remaining systems are between 2.0 and 3.8 pCi/l. |
What fan should be used for a radon mitigation system installation?Radon fans are often oversized for the requirements. A larger fan will not necessarily produce lower radon levels. Homes that have a gravel base under the slab can often use a very efficient 20 watt fan especially if the slab cracks can be sealed. Homes that do not have a gravel base under the slab often require a 70 watt fan. 125 watt fans are used with homes where the mitigation systems will require high airflow or stronger vacuum to overcome the resistance of pulling air through compacted soil under the slab. If a mitigation system needs to move a lot of air the size of the pipe is more important than the strength of the fan. 3" pipe moves up to 80 cfm while 4" pipe moves up to 150 cfm. Visit fan data and fan sizing information. |
Can you reduce loud radon fan vibration or airflow pipe noise?The systems noise is probably due to fan vibration transfer back though building materials rather than the actual fan noise. If the fan is very noisy it could be the fan bearings have gone bad. The fan may also be oversized for the system requirements and a more energy efficient and quieter fan can be installed. System vibration transfer can sometimes be corrected by adjusting or eliminating non essential support straps or brackets. Air flow noise in the pipes can be reduced by wrapping the pipe with an insulating material if the pipe can be accessed. See System Noise Information page for more information. If the system exhaust noise is bothersome, a muffler installed close to or at the exhaust point will help. |
Does a radon system reduce basement humidity or mold?A sizable percentage of the humidity in a basement is from soil gas infiltration. A sub-slab depressurization system stops not only radon but also moist soil gas entry. Customers often report that their de-humidifier in the basement runs less and the basement smells less moldy. A de-humidifier may still be necessary to eliminate other sources of moisture. Jump to Reducing Basement Moisture for lots of additional information. |
What is Thoron?Thoron is another naturally occurring radioactive noble gas that is can enter our homes from the soil or be present in building materials (most commonly via stone foundations). Thoron also decays into solid reactive particles that emit alpha energy and can be a health risk. Thoron however has a very short half life of 55 seconds. This typically does not allow enough time for thoron to enter the air in our homes before it decays and sticks to the soil it is produced in. Read more at Making Thoron Measurements. |
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Download a copy of the above information: Radon FAQ Questions You can ask Bill any question by email: wmbrodhead at gmail.com |
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Radon mitigation call Integra Environmental 610 346-8004 |