Radon Measurement Guide for Homeowners & Home Inspectors InspectAPedia® -
Advice for making accurate measurements of indoor radon levels in buildings
Where to buy radon test kits & how to use a radon test kit
Health effects of exposure to radon gas in homes - a consumer summary
Table of lung cancer risk from radon exposure in air or water
An easy guide to Radon Remediation in Homes
Best methods for cleaning & filtering indoor air
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This article explains procedures for measuring the indoor exposure to radon gas in air or water, and we describe the proper steps to remove radon and improve indoor air quality in homes. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons.
see Radon Hazards for details about radon in buildings, its health effects, how to measure radon, the effect of radon contamination on real estate values and home sales, and a guide on how to remove radon from buildings. Also see ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY for our full list of environmental hazard identification and remedy related to buildings.
While some regions of the country
have more homes with elevated radon levels, high indoor
levels can occur anywhere. For that reason, the EPA
recommends that all homes be tested. Although soil testing
is possible prior to building, there is currently no reliable
way to predict what household levels will be until a
home is completed.
Testing indoor levels is straightforward,
using inexpensive test kits available from hardware
stores or by mail order.
Select a radon test kit that is nationally or
state-certified. Our photo (page top) shows an economical radon test kit available from RTCA - the Radon Testing Corporation of America. Home test kits for radon typically cost $20. for one test canister.
The “action level” established by the EPA
for remediation in homes is 4 pCi/L, although it recommends
that people consider taking action at 2 pCi/L or
above—since no exposure level is without risk. The average
indoor level in the U.S. is 1.3 pCi/L, while outdoor
levels average 0.4 pCi/L.
Radon Testing Methods & Procedure
Radon tests should be conducted away
from drafts, high heat, and high humidity in a
regularly used room on the lowest level in the home
that is used as living space, or in radon-testing lingo: test the lowest habitable space. So if your home has a full-height ceiling basement that is presently un-finished but that could be made into living space, it's reasonable to perform the test there.
Short-term radon tests last for
2 to 90 days, and long-term tests run for up to a year. Place the radon test canister 2-3 feet above the floor on a chair, box, or table, in a house that has been closed for at least 24 hours before starting the test and that will be kept closed for the duration of the test period.
Place the radon test canister close to the center of the room, not by a window, door, or masonry such as a brick fireplace that can cause abnormal readings (some bricks contain and emit radon).
Do not place the radon test kit in a dead-air space, and do not place the canister where the building's HVAC system will blow on or across it.
Because radon levels vary daily and seasonally,
longer test periods are better indicators of the average
level. However, if two short-term tests yield an average
result greater than 4 pCi/L, the EPA recommends
taking steps to lower the level to 2 pCi/L or lower.
Since 1985, millions of homes have been tested for
radon, and an estimated 800,000 homes have been
mitigated.
see Radon Enviro-Scare for a full discussion of the normal cycle of public fear that accompanies the discovery and publicity of various environmental hazards, including radon gas and see Enviro-Scare, the Cycle of Public Fear for our article about consumer environmental safety worry cycles that change over time.
For a Thorough Background in Radon Hazards, Radon Mitigation, & the History of Radon Concerns in the U.S. also see these articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
"Radon's Threat Can Be Subdued", part 1 - William Turner, Terry Brennan, Solar Age MagazineRadon and its progeny are the slipperiest pollutants in the indoor environment, but there are simple ways to keep radon and its relations at bay.
"Radon's Threat Can Be Subdued", part 3 - standards for airborne radon levels in buildings and recommended levels of radon for action, how radon is best detected, and radon action plan.
"Radon's Threat Can Be Subdued", part 4 - radon prevention advice for new construction, radon in well water - how it is removed, sources of information about radon gas and radon contamination.
"Defeating Radon" part 1- Terry Brennan, Bill Turner, Solar Age Magazine - How does radon get into buildings, how do I know if a building has a radon gas problem, how can I solve radon problems in existing homes, and what can I do to prevent radon from entering new homes. Part 1: where Radon comes from, how to diagnose radon
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com.
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