Lesson 7 How do you conduct a radon test?
Prepare for the test • Determine timing of the test • How long test will last • Appropriate weather conditions during test period • Convenience of owner or resident • Determine the location of the test • Consider how to prevent or detect interference
Prepare for the test Topics to be covered in lesson on quality control • Prepare necessary documents • Prepare the device you will use
Determine timing of test • How long test must run • At least 48 hours for most devices • Some devices require longer test period • Convenience of owner or resident • Consideration helps encourage cooperation • Weather predictions for the test period
Weather conditions Check local news stations for weather forecasts • Heavy rain storm • Hurricane • Major snow storm • Rapid barometric pressure changes • High winds (greater than 30 mph) Do not test • During extreme weather • When extreme weather is predicted within 48 hours
Extreme weather effects Rain, snow, or freezing temperatures • May seal soil and prevent radon from moving to outdoor air • May thus increase indoor radon level High winds (greater than 30 mph) • Create greater difference in indoor and outdoor air pressure • Make radon concentrations more variable • OK to test if high winds are normal for area (for example, along coast)
Extreme weather effects • May change rate of radon entry • Create greater difference in indoor and outdoor air pressure Rapid changes in barometric pressure Record barometric pressure to identify weather conditions that may affect the test
Determine placement of the device Which level of the home? Which room on that level? What location within the room?
If the home is not being sold, test at lowest level where people actually live If the home is being sold, test at lowest level where people could live without renovating the area Buyers and sellers should discuss and agree on placement Choose the level to test EPA: Test at the lowest level suitable for occupancy
If a home has more than one type of foundation, test in or above each area For example If the home has a basement that is or could be a living space, test in the basement If the home has a crawl space, test in the roomabove the crawl space If the home has a room with a cement floor ("slab-on-grade"), test in that room Consider foundation types
A practical question To test, or not to test, in an unfinished basement? Worst-case scenario
Examples Bedroom Living room Family room Den Playroom Butnot Kitchen Bathroom Laundry room Hallway Closet Crawl space Choose the room to test Select a room that is used or will be used regularly
Bathroom Which rooms may be suitable for testing? Master bedroom Kitchen Laundry room Closet Hallway Bathroom Garage Family room Living room Assume this plan represents the appropriate level in this home
Which rooms may be suitable for testing? Master bedroom Family room Living room Remember to check with both seller and buyer.
Choose the location within the room Place the device • Where it will not be disturbed • Where there is enough room • More than 1 foot from exterior walls that have no windows or other potential openings • More than 3 feet from windows, doors, or other potential openings in the exterior wall • More than 4 inches from other objects • In the breathing zone • More than 20 inches from the floor • For devices that hang from the ceiling, 6 to 8 feet from the floor
Choose a location within a room Exterior wall Bed Night- stand Window Book case 2’ Interior wall Exterior wall 14’ Desk 4’ 2’ Door Interior wall
Test interference • Purposeful interference Oops! Oops! • Accidental interference Radon device Radon device
Common forms of test interference Influencing the device • Move device • Block sampling mechanism • Cover device • Turn off device • Apply heat or humidity Changing the test area • Open windows or doors • Increase ventilation
Methods to detect interference • Use a continuous device that frequently records radon levels to detect unusual changes • Use a motion detector that shows whether the device has been moved • Use a proximity detector that shows whether people have been in the room when radon levels have changed • Use a device that does not allow residents to see preliminary results
More methods to detect interference • Record the temperature and humidity frequently to indicate whether doors or windows are opened during the test • Carefully place the device • Place precisely so you can detect any change of position • Place at edge of support to discourage covering device • Apply seals (caulk or tape) • To device to indicate whether it is opened • To nearby windows and doors to show if they are opened • Between device and its support to show if device is moved • To device and other components to indicate tampering
Seals • Must stick to many surfaces • Must be easy to remove without damaging the surface • Must not be resealable or must show evidence of interference • Must be unusual enough to prevent seller from duplicating • Should be visible to discourage tampering Tamper-evident seal Just kidding. Not this kind of seal.
Questions? About preparing for the test
Prepare residents for test Before test starts • Explain purpose of test • Explain test procedure and conditions • Explain importance of cooperating with test requirements • Give residents written information about test • Ask them to sign agreement to cooperate with test requirements • Answer their questions
Explain purpose The people who are interested in buying your home want to know the level of radon. Radon is an invisible radioactive gas that causes lung cancer. The only way to know if you have a dangerous level of radon is to measure it. This test will measure the radon in the air in your home. If your home does have a high radon level, a system to reduce the level should be installed to protect the health of everyone who lives there. Inspector Hank James
Explain test procedure I’ll place two charcoal canisters in your basement around 8 AM on Wednesday, if that’s convenient for you. These devices are harmless. Although they measure a radioactive gas, they are not radioactive. They’ll need to remain in place for at least 48 hours. I’d like to pick them up around 10 AM Friday. Does that schedule work for you?
Explain conditionsfor short-term test You’ll need to maintain some simple conditions to make sure that the test is accurate. Starting 12 hours before the test and during the whole test, please keep your home closed as much as possible. Since the test will last 48 hours, your home must stay closed for 60 hours in all. Keep all windows, outside vents, and outside doors closed. Of course, you may open a door to enter or leave your home, but close the door quickly. Please shut down internal-external air exchange systems, such as your attic and window fans. You do not need to turn off your furnace fan. You mentioned that your home already has a radon mitigation system installed and that it is working properly. Please make sure that the fan is running at least 24 hours before we start the test. And keep the system running during the entire test.
Explain interference • It is standard procedure for me to use methods that detect and document interference. If I have evidence of interference, the test will not be valid and the results will not be accepted. • Interference means • Changing the test conditions (for example, by opening windows) or • Disturbing the device (for example, by moving it). • And I should tell you that interfering with the test may actually increase, rather than decrease, the radon level we are measuring. • I’ll ask you to sign a document stating that you will maintain the required test conditions and will not disturb the device. • Thanks for your cooperation.
Ask residents if they have questions • Why? • Where? • When? • How long? • Is it safe? • What do you mean by closed conditions? • What do you mean by interference?
Ask residents if they have questions • Why? • Where? • When? • How long? • Is it safe? • What do you mean by closed conditions? • What do you mean by interference? Rick, the reluctant resident
Questions? About preparing residents for the test
Show your photo identification to the client and resident Place device or devices in appropriate location Conducting the test • Remind residents • How long test will take (at least 48 hours) • Not to disturb device • To operate heating or recirculating air conditioning system normally • If radon-reduction system is already operating, to continue operating it during test
Conducting the test For short-term tests (less than 1 week) • Confirm that home has been closed for at least 12 hours before the start of the test • Remind residents • To keep home closed as much as possible • To operate only air-conditioning units that recirculate interior air
Information about device Manufacturer Type/model Serial or ID number Times Start date and time Stop date and time Exact location of device on diagram of room and building Other building information Type of building Type of heating system Foundation types Operation of humidifiers, air filters, electrostatic precipitators, and clothes dryers Test conditions Document the test
At end of test • Collect device • Confirm that test conditions (closed house) were maintained • Confirm that device was not interfered with • Complete documents • Send device to lab promptly
Report results • Report radon results in pCi/L • Report no more than 1 decimal place • Example: 4.3 pCi/L • Report radon decay products results in WL • Report no more than 3 decimal places • Example: 0.033 WL If you convert between pCi/L and WL, explain conversion
Determine timing for test Determine placement of device Level in home Room Location within room Consider how to prevent or detect interference with test Interference with test conditions Interference with device Summary Preparing for a test
SummaryPreparing residents • Explain purpose of test • Explain test procedure and conditions • Explain importance of cooperating with test requirements • Give residents written information about test • Ask them to sign agreement to cooperate with test requirements • Answer their questions
SummaryConducting the test • Place device in appropriate location • Remind residents of test conditions • Document the test • Check for interference • Send device to lab promptly • Report results