U.S. ENVIRONMENTAL PROTECTION AGENCY 

OFFICE OF INSPECTOR GENERAL 

Catalyst for Improving the Environment 

Evaluation Report 

EPA Does Not Provide 

Oversight of Radon Testing 

Accuracy and Reliability 

 Report No. 09-P-0151 

 May 4, 2009 
 

Report Contributors:

Abbreviations 

 Rick Beusse 

 John Bishop 

 Dan Howard 

 Tiffine Johnson-Davis 

 Rich Jones 

 Bill Nelson 

ASTM American Society for Testing and Materials 

EPA U.S. Environmental Protection Agency 

IRAA Indoor Radon Abatement Act 

NEHA National Environmental Health Association 

NRPP National Radon Proficiency Program 

NRSB National Radon Safety Board 

OAR Office of Air and Radiation 

OCFO Office of the Chief Financial Officer 

OIG Office of Inspector General 

PAR Performance and Accountability Report 

pCi/L Picocuries Per Liter (of air) 

R&IE Radon Laboratory at the Radiation and Indoor Environments National Laboratory 

Cover art:	 Three types of residential radon testing devices (from left): electret ion 

detector, alpha track detector, and charcoal canister. (Source: EPA Website, 

http://www.epa.gov/radon/pubs/physic.html). 
 

U.S. Environmental Protection Agency 09-P-0151 

May 4, 2009 Office of Inspector General 

At a Glance 

Catalyst for Improving the Environment 

Why We Did This Review 

The U.S. Environmental 

Protection Agency (EPA) 

estimates that about 20,000 

lung cancer deaths each year 

in the United States are related 

to indoor exposure to radon. 

The only way to know 

whether indoor radon levels 

are elevated is to test the 

indoor air. The purpose of 

this evaluation was to 

determine how EPA ensures 

that radon testing devices and 

radon laboratories provide 

accurate and reliable data on 

indoor radon levels. 

Background 

Radon is a naturally occurring 

gas that seeps out of rocks and 

soil into the air in homes from 

the movement of gases 

beneath homes. Radon builds 

up to higher concentrations 

indoors when it is unable to 

disperse. Radon attaches to 

tiny dust particles in indoor air 

that are easily inhaled into the 

lungs and can adhere to the 

lining of lungs. 

For further information, 

contact our Office of 

Congressional, Public Affairs 

and Management at 

(202) 566-2391. 

To view the full report, 

click on the following link: 

www.epa.gov/oig/reports/2009/ 

20090504-09-P-0151.pdf 

EPA Does Not Provide Oversight of 

Radon Testing Accuracy and Reliability

 What We Found 

EPA does not perform oversight of radon testing device accuracy or reliability. 

The 1988 Indoor Radon Abatement Act required that EPA establish proficiency 

programs for firms offering radon-related services, including testing and 

mitigation. EPA established and operated proficiency programs until 1998, when 

it disinvested in these programs. According to Agency representatives, EPA has 

neither the authority nor resources to ensure radon testing devices and testing 

laboratories are accurate and reliable. EPA asserts that it shares oversight 

responsibility with States and industry, including the two national proficiency 

programs operating under private auspices. However, without oversight, EPA 

cannot assure that radon testing devices provide accurate data on indoor radon 

risks or that radon testing laboratories accurately analyze and report radon results. 

Recent studies – while not nationwide in scope – have identified problems with 

the accuracy of radon testing devices. Also, a recent New England study 

identified problems with the quality of laboratory analyses of radon testing. 

Nonetheless, a key 2009 EPA publication on the Agency’s Website continues to 

state that radon testing devices provide reliable measurements of indoor radon 

levels. In its 2009 A Citizen's Guide to Radon: The Guide to Protecting Yourself 

and Your Family from Radon, EPA states: 

MYTH: Radon testing devices are not reliable and are difficult to find. 

FACT: Reliable testing devices are available from qualified radon 

testers and companies. 

However, EPA does not have data within the last 10 years to support that radon 

test kits or testers are reliable. 

What We Recommended 

We recommended that the Agency disclose that while radon testing is 

recommended, EPA cannot provide assurance that commercially available radon 

testing devices or testing laboratories are accurate and reliable. EPA generally 

agreed with this recommendation and stated that it will review and revise both its 

Web-based and printed public materials, as appropriate. However, the Agency did 

not provide information on how it intends to characterize the accuracy and 

reliability of radon testing in its public documents. More information is needed to 

assess whether EPA’s planned actions meet the intent of this recommendation. 

We also recommended that EPA inform Congress that the limitations of reliable 

testing for radon may negatively affect achieving Indoor Radon Abatement Act 

goals. EPA agreed with this recommendation and plans to include this in its next 

Performance and Accountability Report to Congress. The Agency’s planned 

action meets the intent of this recommendation. 
 

 

 

 

 

 

Assistant Inspector General for Program Evaluation 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF 

INSPECTOR GENERAL 

May 4, 2009 

MEMORANDUM 

SUBJECT: EPA Does Not Provide Oversight of Radon Testing 

Accuracy and Reliability 

Report No. 09-P-0151 

FROM: Wade T. Najjum 

TO: Elizabeth Craig 

Acting Assistant Administrator for Air and Radiation 

This is our report on the subject evaluation conducted by the Office of Inspector General (OIG) 

of the U.S. Environmental Protection Agency (EPA). This report contains findings that describe 

the problems the OIG has identified and corrective actions the OIG recommends. This report 

represents the opinion of the OIG and does not necessarily represent the final EPA position. 

Final determinations on matters in this report will be made by EPA managers in accordance with 

established audit resolution procedures. 

The estimated cost of this report – calculated by multiplying the project’s staff days by the 

applicable daily full cost billing rates in effect at the time – is $384,100. 

Action Required 

In accordance with EPA Manual 2750, EPA’s Audit Management Process, you are required to 

provide a written response to this report within 90 calendar days. You should include a 

corrective actions plan for agreed upon actions, including milestone dates. We have no 

objections to the further release of this report to the public. This report will be available at 

http://www.epa.gov/oig. 

If you or your staff have any questions regarding this report, please contact me at (202) 566-0827 

or najjum.wade@epa.gov; or Rick Beusse, Director for Program Evaluation, Air and Research 

Issues, at (919) 541-5747 or beusse.rick@epa.gov. 
 

 

 

 

 

 

 

 

EPA Does Not Provide Oversight of 09-P-0151 

Radon Testing Accuracy and Reliability 

Table of Contents 

Purpose........................................................................................................................ 1 

Background ................................................................................................................. 1 

Scope and Methodology............................................................................................. 2 

Results of Review ....................................................................................................... 3 

Limited Authority and Resources to Assess Accuracy of 

 Radon Testing Devices ............................................................................... 3 

Concerns with Accuracy and Reliability of 

Recent Studies Identified Problems with Accuracy of 

Recent Studies Identified Problems with Quality of 

EPA Website Provides Assurances Related to Accuracy of 

 Testing Devices........................................................................................... 4 

 Radon Testing Devices ............................................................................... 4 

Radon Laboratory Analyses ........................................................................ 6 

Radon Testing Devices Without Sufficient Current Knowledge................... 6 

Conclusions................................................................................................................. 7 

Recommendations...................................................................................................... 8 

Agency Comments and OIG Evaluation ................................................................... 8 

Status of Recommendations and Potential Monetary Benefits.............................. 9 

Appendices 

A Agency Response to Draft Report ....................................................................... 10
 

B OIG Evaluation of Agency Response .................................................................. 13
 

C Distribution ............................................................................................................ 15
 
 

 

 09-P-0151
 

Purpose 

The purpose of this evaluation was to determine how the U.S. Environmental Protection Agency 

(EPA) ensures that radon testing devices and radon laboratories provide accurate and reliable 

data on indoor radon levels. Our evaluation objectives were to determine how EPA ensures that: 

• radon testing devices provide accurate data on indoor radon risks, and 

• radon testing laboratories accurately analyze and report indoor radon results. 

Background 

Radon is a naturally occurring gas that seeps out of rocks and soil into the air in homes from the 

movement of gases beneath homes. Radon builds up to higher concentrations indoors when it is 

unable to disperse. Radon atoms decay by emitting alpha particles. The decay product is also 

radioactive and attaches to tiny dust particles in indoor air that are easily inhaled into the lungs 

and can adhere to the lining of lungs. As this product decays, it emits alpha radiation, which has 

the potential to damage cells in the lungs. This can disrupt the DNA of lung cells, and can lead 

to lung cancer. EPA estimates that about 20,000 lung cancer deaths each year in the United 

States are related to indoor exposure to radon. A 1999 report by the National Academy of 

Sciences estimated about 15,000 to 22,000 Americans die every year from radon-related lung 

cancer,

1

 or 10 to 14 percent of all persons each year who die from lung cancer in the United 

States. This makes indoor radon the second leading cause of lung cancer, after cigarette 

smoking. 

In 2005, the U.S. Surgeon General issued a national health advisory warning the American 

public about the risks of breathing indoor radon. EPA and the Surgeon General recommend 

testing all homes below the third floor for radon. They also recommended taking mitigation 

action in homes with radon levels at or above 4 picocuries per liter (pCi/L), EPA’s recommended 

action level. According to EPA, the 4.0 pCi/L action level is not the maximum safe level for radon 

in the home, since any exposure to radon poses some risk. Instead, the 4.0 pCi/L action level was a 

decision based on EPA’s assessment of technology and cost. The only way to know whether 

indoor radon levels are elevated is to test the indoor air. 

Due to the widespread recognition of health threats from radon exposure in the 1980s and the 

need for competent radon service providers, EPA established the Radon Measurement 

Proficiency Program in 1986 to assist consumers in identifying organizations capable of 

providing reliable radon measurement analysis services. EPA established the Radon Contractor 

Proficiency Program in 1989 to evaluate the proficiency of radon mitigators in residences and 

provide information to the public on proficient mitigators. In 1991, EPA expanded the 

proficiency programs, adding a component to evaluate the proficiency of individuals who 

provide radon measurement services in the home. 

These programs were later consolidated in 1995 to form the National Radon Proficiency 

Program (NRPP). The authority to establish these programs was provided to EPA through 

1 Health Effects of Exposure to Radon: Biological Effects of Ionizing Radiation VI, Committee on Health Risks of 

Exposure to Radon, Board on Radiation Effects Research, Commission on Life Sciences, National Research 

Council, National Academy Press, Washington, DC. 1999. 

1 
 

 

 

 

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Section 305 of the 1988 Indoor Radon Abatement Act (IRAA). In addition to requiring that EPA 

assist States with the development of radon measurement and mitigation methods, Section 305 of 

the IRAA also required EPA to establish a: 

Proficiency Rating Program - This section also establishes that $1.5 million will 

be given for EPA to establish proficiency programs for firms offering radonrelated services, including testing and mitigation. The program would later be 

funded through a user-fee system. 

EPA operated the NRPP from 1995 until 1998, when it disinvested in the program. EPA made a 

one-time “acknowledgment” to both of the existing non-federal national radon proficiency 

programs in March 2001. These were the National Radon Safety Board (NRSB) program and the 

National Environmental Health Association’s (NEHA’s) NRPP. EPA’s official acknowledgement 

of these two proficiency programs ended December 31, 2002. 

Scope and Methodology 

We conducted our evaluation from May 2008 to March 2009. Our evaluation focused on the 

Indoor Environments Division within EPA’s Office of Air and Radiation, Office of Radiation 

and Indoor Air, located in Washington, DC. We interviewed program staff and managers from 

EPA’s Office of Radiation and Indoor Air, and obtained and reviewed applicable radon program 

policies, procedures, and guidance. In addition, we interviewed key indoor radon stakeholders, 

including representatives of the following non-governmental groups: 

•	 The NEHA’s NRPP 

•	 The NRSB 

•	 A calibration laboratory for radon testing devices 

•	 A major supplier of “do-it-yourself” test kits 

We reviewed documents on the accuracy of radon testing devices and laboratories, including: 

•	 A January 2008 report, Blind Testing of Commercially Available Short-Term Radon 

Detectors, by Kainan Sun, Gregory Budd, Steven McLemore, and R. William Field 

•	 A February 2008 report, A Test of Radon Service Providers Available on the Internet, 

by J. Chen, R. Falcomer, L. Bergman, J. Wierdsma, and J. Ly 

•	 A July 2006 report, Pilot Project for the Blind Testing of Certain Passive Radon Test 

Devices Commonly Used in the New England States, by C. Juliano and W. Bell 

•	 A September 2008 Consumer Reports article, Lead and Radon Test Kits - Challenging 

Choices 

We also reviewed Website information for the two proficiency programs (NEHA and NRSB). 

We conducted this evaluation in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the evaluation to obtain sufficient, 

appropriate evidence to provide a reasonable basis for our findings and conclusions based on our 

2 
 

 

 

 

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evaluation objectives. We believe the evidence obtained provides a reasonable basis for our 

findings and conclusions. 

Generally accepted government auditing standards require that auditors obtain an understanding 

of internal controls significant to the audit objectives and consider whether specific internal 

control procedures have been properly designed and placed in operation. We performed a 

limited review of management and internal controls as they related to our objectives. We 

reviewed EPA guidance documents, including the NRPP Handbook dated July 1996 and the 

NRPP Guidance on Quality Assurance dated October 1997. We did not perform a detailed 

review of management controls, since EPA asserts that it has no oversight responsibility for the 

accuracy and reliability of radon testing. We had performed a review of management controls 

for the overall radon program during a recent evaluation, More Action Needed to Protect Public 

from Indoor Radon Risks (Report No. 08-P-0174), dated June 3, 2008. There were no other prior 

reports on which to follow up. 

Results of Review 

Limited Authority and Resources to Assess Accuracy of Radon Testing Devices 

EPA currently exercises no oversight over radon testing devices, laboratories, or the privately 

run proficiency programs. EPA decided to stop operating the NRPP in 1998 after holding public 

meetings with principal radon stakeholders during a 2-year period on how to privatize the 

proficiency program. EPA cited three factors that it considered when deciding to stop operating 

the NRPP: 

• Costs/budget issues 

• The proper role of the Federal Government 

• Maturity of the industry 

EPA’s decision led to the formation of two privately run radon proficiency programs: the 

NEHA-NRPP and the NRSB. Both proficiency programs were formed in 1998 and used the 

same framework EPA had established for its federal NRPP program. The private proficiency 

programs offer proficiency listing, accreditation, and certification in radon testing and mitigation. 

Neither of the programs report to EPA nor receive EPA funding. Representatives from both 

proficiency programs told us EPA provides no oversight of their programs. 

EPA initially recognized the two private proficiency programs as equivalent to its previous 

federal program. This official “acknowledgement” ended December 31, 2002, and has not been 

renewed. EPA recognizes the two programs by referring the public to them on its public 

Website. Whether operated by EPA or the privately run proficiency programs, participation by 

firms offering radon-related services, including testing and mitigation, has been voluntary. 

In 2006, EPA offered members of the radon stakeholder community the opportunity to 

participate in a professionally-facilitated stakeholder dialogue group, a venue for communication 

and problem-solving. According to EPA, this group has worked to address radon testing device 

accuracy issues. These radon stakeholders – consisting of industry, State and local agencies, 

3 
 

 

 

 

 

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academia, and EPA – meet periodically to discuss the issues surrounding radon testing as well as 

possible solutions to issues. There are no published reports provided to the general public from 

the radon stakeholder meetings. 

According to EPA Center for Radon and Air Toxics representatives, it has neither the authority 

nor resources to ensure radon testing devices and testing laboratories are accurate and reliable. 

EPA stopped operating the NRPP when its authorization expired and the budgetary impact was 

considered. 

Concerns with Accuracy and Reliability of Testing Devices 

When EPA privatized the NRPP in 1998, many radon testing devices were grandfathered 

(not tested by the private proficiency programs) into the current private proficiency programs. 

However, according to an NRSB representative, not all of the devices were evaluated prior to 

being grandfathered in. Further, there are testing devices on the market that are not listed by 

either proficiency program. 

NEHA-NRPP representatives informed us that during the original EPA evaluation process, if 

several applications were submitted at the same time for similar radon testing devices, EPA 

would only evaluate one of them but certify all of them. However, NEHA-NRPP believes these 

devices may not all have had the same accuracy. NEHA-NRPP also informed us there are 

companies selling devices that may have been modified significantly since they were originally 

evaluated, but that the companies have never re-submitted the devices for re-evaluation. 

Because of these concerns, NEHA-NRPP believes that all devices evaluated prior to 2006 should 

be re-evaluated. 

A representative from a calibration laboratory for radon testing devices (one of the larger private 

laboratories, according to EPA) also had concerns with the accuracy of radon testing devices. 

These concerns included whether all testing devices on EPA’s original approved list were ever 

evaluated. The representative told us that some devices probably could not pass an evaluation, 

some devices might not be accurate at high humidity, and staff at some laboratories may not be 

trained in calibration. The representative also expressed concern that there was no mechanism 

for re-evaluating devices that were added to the approved list of devices years ago but might not 

be able to pass now, and suggested periodic re-evaluation of devices. 

Both proficiency programs had concerns with consistency of State enforcement of radon testing. 

While some States require that radon vendors be certified, not all States do. As a result, 

enforcement options are limited. For example, if a proficiency program decided to take a radon 

testing device off its list of certified devices, the vendor could still operate in States that do not 

have certification requirements. 

Recent Studies Identified Problems with Accuracy of Radon Testing Devices 

Two recent U.S. studies that blind-tested short-term radon detectors commercially available in 

the United States found significant problems in both electret ion chambers and diffusion barrier 

charcoal canisters (with and without liquid scintillation). A 2006 study found that devices for 

five of six companies failed EPA’s 25-percent relative error accuracy guideline. A 2008 study 

4 
 

 

 

 

 

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found that radon testing devices for three of seven companies failed the same accuracy guideline, 

even under ideal conditions of constant temperature, humidity, and radon concentration 

[emphasis added]. The test results suggested systematic bias for the three companies, which 

merited further investigation. According to the 2008 study, prior to the recent studies, published 

studies examining the accuracy and precision of commercially available short-term radon 

detectors were rare. An EPA staff member participated in this study.2 

Further, a September 2008 Consumer Reports article concluded that long-term devices (both 

alpha track and digital readout meters) were more accurate when compared against a calibrated 

standard than short-term devices (charcoal canister). Two short-term devices (charcoal canister) 

of the seven tested underreported radon levels by almost 40 percent. This exceeds the 25-percent 

guideline established by EPA. 

A 2008 peer reviewed Canadian study of 36 short-term radon detectors available over the 

Internet found some problems.3 The Radiation Protection Bureau of Health Canada tested 

34 activated charcoal canisters manufactured by 10 companies. Two tests of charcoal canisters 

were conducted: one with radon concentrations at or near the Canadian action level, and the 

other at concentrations about twice that level. On the first test of eight companies manufacturing 

charcoal canisters, three companies (four canisters total) had relative errors equal or greater than 

24 percent. On the second test at the higher radon concentration, of the eight companies 

manufacturing charcoal canisters, three companies (three canisters total) had relative errors equal 

or greater than 24 percent. Also, in the second test, the results for four detectors (11 percent) 

manufactured by two companies were declared invalid because of excessive delay in providing 

test results. The study also tested two alpha track (long-term) detectors. Alpha track detectors 

had relative errors of 10 and 4.5 percent. The test results showed that online radon testing 

services could collectively meet Canada's performance requirement (that readings be within 

+50% and -33% of reference values, 95% of the time); however, the quality of a few service 

providers needed to be improved. 

EPA stated that there are multiple variables that affect the accuracy and precision of radon test 

results, including: 

• The device itself 

• The laboratory 

• The skills and reliability of the person deploying the test 

• The time it takes to mail the test 

• A significant randomness factor in the ability of any device to detect radon itself 

Nonetheless, the Agency has no radon testing oversight data and these are the best data available. 

2 Blind Testing of Commercially Available Short-Term Radon Detectors, by Kainan Sun, Gregory Budd (EPA, 

Office of Air and Radiation, Office of Radiation and Indoor Environments, National Lab in Las Vegas, NV), Steven
 

McLemore, and R. William Field, June 2008, Volume 94, Number 6. Health and Physics Society. 

3 A Test of Radon Service Providers Available on the Internet, by J. Chen, R. Falcomer, L. Bergman, J. Wierdsma, 

and J. Ly, accepted for publication on 25 February 2008 by Indoor Air 2008. 

5 
 

 

 

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Recent Studies Identified Problems With Quality of Radon Laboratory Analyses 

Concerned about the quality of radon measurements, the New England States’ Radon Programs 

jointly undertook a double-blind study4

 of radon measurement laboratories operating in their 

States. In this 2006 study,5

 researchers concluded that there are relatively high percentages of 

laboratories performing radon analysis in the New England States that are unable to successfully 

analyze proficiency samples. Laboratories analyzing radon gas in the New England States were 

sent a small number of passive 48-hour test devices for the purpose of estimating analytical 

precision and accuracy. The test devices were exposed to known conditions in EPA’s radon 

calibration chamber in two batches. A laboratory is considered proficient in radon testing when 

all of the results in a batch of performance tests are within 25 percent of the reference value. 

According to this study: 

• Six of 14 laboratories (43 percent) were not proficient in radon testing in batch 1. 

• Four of 14 laboratories (29 percent) were not proficient in radon testing in batch 2. 

The researchers concluded that to maintain an accurate and timely measure of radon testing 

proficiency, a routine testing program should be established. Although EPA funded this pilot 

project, the Agency did not provide additional funding for such projects after the pilot project. 

EPA Website Provides Assurances Related to Accuracy of Radon Testing 

Devices Without Sufficient Current Knowledge 

EPA has not reviewed the two private proficiency programs since its original acknowledgement 

of the two programs in 2001. EPA’s Website recommends that anyone interested in finding a 

qualified radon service professional to test or mitigate their home should contact their State 

radon office or one or both of the two privately-run national radon programs that offer 

proficiency listing/accreditation/certification in radon testing and mitigation. Similarly, a key 

2009 EPA publication on the Agency’s Website continues to state that radon testing devices 

provide reliable measurements of indoor radon levels. In its 2009 radon guide, A Citizen's Guide 

to Radon: The Guide to Protecting Yourself and Your Family from Radon, EPA states: 

MYTH: Radon testing devices are not reliable and are difficult to find. 

FACT: Reliable testing devices are available from qualified radon testers and 

companies. Reliable testing devices are also available by phone or mail-order, 

and can be purchased in hardware stores and other retail outlets. Call your state 

radon office for help in identifying radon testing companies. 

However, EPA does not have data within the last 10 years to support that radon test kits or radon 

testers are reliable. Despite the Agency’s disclaimer that it has limited involvement in the radon 

proficiency programs and its reference to any specific products or services do not necessarily 

imply its endorsement, EPA lacks sufficient current knowledge of the radon testing and 

4

 A “double blind” study is one where both the researcher and participants are not aware of which treatment each 

participant is receiving. 

5 Pilot Project for the Blind Testing of Certain Passive Radon Test Devices Commonly Used in the New England 

States, by C. Juliano and W. Bell, July 2006. 

6 
 

 

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laboratory proficiency programs to support statements regarding radon testing device accuracy 

and reliability. 

The Director of EPA’s Center for Radon and Air Toxics (within the Indoor Environments 

Division) said that given the fundamentally difficult task of measuring radon in homes, the 

enormous population exposed, and the reality that citizens are the ones who must choose to act 

independently to measure, evaluate, and reduce their risk, it is appropriate to sacrifice “some 

degrees of precision” to promote ease of use, so long as the results of the system achieve 

necessary risk reduction. He stated that: 

Even when there is a “false positive,” i.e., the reading is above 4.0 while the actual value 

may be somewhat below 4.0, the decision to fix the home will result in substantial risk 

reduction. This is true because our national risk estimates – over 20,000 deaths annually 

– are based on lifetime exposure at the indoor background level of 1.25 pC/L. 

Mitigations that take place at levels below 4.0 pC/L will result in risk reduction. For this 

reason EPA’s policy is to recommend fixing when the test result is between 2-4 pCi/L 

(see Citizen’s Guide). It is also true that some ‘false negative’ test results occur, leading 

the occupant to assume no action is needed when an accurate measurement would 

indicate otherwise. However, we believe the risk of such a result is acceptable as a 

matter of public policy, compared to the much greater risk associated with providing no 

easy and affordable mechanism for owners to test their homes at all. 

The Agency is suggesting that devices that are easy to use, affordable, and of uncertain precision 

and reliability are acceptable for measuring indoor radon risks. However, EPA does not have 

recent data on the number of false positives or false negatives that occur, and was not able to 

provide any studies or any other evidentiary basis within the last 10 years to support its 

assumptions. 

Conclusions 

EPA does not have data within the last 10 years to support that radon test kits or radon testers are 

reliable. EPA has not reviewed the two private proficiency programs since originally 

acknowledging them in 2001. Several recent studies – while not nationwide in scope – have 

identified problems with the accuracy of radon testing devices and quality of laboratory analyses. 

Both EPA and the U.S. Surgeon General recommend testing homes for radon. However, EPA 

cannot provide the public with reasonable assurance that radon testing devices and laboratory 

proficiency programs provide accurate data on indoor radon risks. Further, EPA cannot assure 

the public that radon laboratories accurately analyze and report indoor radon test results. We 

believe the lack of assurance also has negative consequences for EPA’s efforts to protect the 

public from indoor radon risks under the IRAA. 

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Recommendations 

We recommend that the Assistant Administrator for Air and Radiation: 

1. Disclose to the public that while radon testing is recommended by the Agency and the 

U.S. Surgeon General, EPA cannot provide assurance that commercially available radon 

testing devices or radon testing laboratories are accurate and reliable. 

2. Inform Congress that the limitations of reliable testing for radon may negatively affect 

achieving the IRAA goals. 

Agency Comments and OIG Evaluation 

The Agency said it generally agreed with Recommendation 1. The Agency stated that it will 

review its Web-based materials and revise them, as appropriate, within 60 days; printed 

documents will take longer to revise due to printing cycles. However, the Agency did not 

provide information related to what it will disclose and how it intends to characterize the 

accuracy and reliability of radon testing in these documents. Additional information is needed as 

to EPA’s planned revisions of public documents, such as whether they will explicitly state that 

commercially available radon testing devices or radon testing laboratories may not be accurate 

and reliable. We will need this information to assess whether EPA’s planned actions meet the 

intent of this recommendation. The recommendation will remain open and unresolved until an 

Agency corrective action plan is completed that provides details on how the Agency will 

implement the recommendation. 

The Agency agreed with Recommendation 2. The Office of Air and Radiation stated that it will 

work with the Office of the Chief Financial Officer to initiate this update to the Agency’s next 

Performance and Accountability Report to Congress within 90 days of the final OIG report. It 

plans to use this report to notify Congress that the limitations of reliable testing for radon may 

negatively affect achieving the IRAA goals. This response meets the intent of our 

recommendation. The recommendation will remain open until the Agency provides an 

acceptable action plan that includes a completion date. 

The Agency’s complete written response is in Appendix A. Details on our evaluation of those 

comments are in Appendix B. 

8 
 

 

 

 

 

 

 

 

 09-P-0151 

Status of Recommendations and 

Potential Monetary Benefits 

POTENTIAL MONETARY 

RECOMMENDATIONS BENEFITS (in $000s) 

Rec. 

No. 

1 

2 

Page 

No.

8 

8 

 Subject 

Disclose to the public that while radon testing is 

recommended by the Agency and the U.S. 

Surgeon General, EPA cannot provide assurance 

that commercially available radon testing devices 

or radon testing laboratories are accurate and 

reliable. 

Inform Congress that the limitations of reliable 

testing for radon may negatively affect achieving 

the IRAA goals. 

Status1 

U 

O 

Action Official 

Assistant Administrator for 

Air and Radiation 

Assistant Administrator for 

Air and Radiation 

Planned 

Completion 

Date 

Claimed 

Amount 

Agreed To 

Amount 

1 O = recommendation is open with agreed-to corrective actions pending 

C = recommendation is closed with all agreed-to actions completed 

U = recommendation is undecided with resolution efforts in progress 

9 
 

 

 

 

 

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Appendix A 

Agency Response to Draft Report 

Memorandum 

SUBJECT: Comments on the Draft Evaluation Report: EPA Does Not Provide Oversight of 

Radon Testing Accuracy and Reliability 

FROM: Elizabeth Craig 

 Acting Assistant Administrator 

Office of Air and Radiation 

TO: Wade T. Najjum 

Assistant Inspector General for Program Evaluation 

Office of Inspector General 

The EPA Office of Air and Radiation appreciates the opportunity to comment on the 

OIG’s draft report “EPA Does Not Provide Oversight of Radon Testing Accuracy and 

Reliability," (Assignment No. Project No. 2008-0186, March 10). Thank you for your 

observations on the important public health challenge of reducing indoor radon exposure. 

Our response to the draft findings are as follows: 

Recommendation 1 - Disclose to the public that while radon testing is recommended by the 

Agency and the U.S. Surgeon General, EPA cannot provide assurance that commercially 

available radon testing devices or radon testing laboratories are accurate and reliable. 

OAR generally concurs with OIG’s recommendation that EPA should not assure the 

public of greater accuracy than these simple devices have been demonstrated to deliver. The 

report points to an instance in which we appear to have offered such an assurance. OAR will 

review its public materials and revise them, as appropriate, within 60 days. Note that this applies 

to our web-based information; our printed documents will take longer to revise due to printing 

cycles. 

See Appendix B, Note 1, for OIG Response 

However, OAR believes the report would benefit from additional information. For 

example, while OAR acknowledges OIG’s main point, that EPA does not oversee a 

comprehensive national system of quality assurance for the testing and certification of radon 

measurement devices and laboratories in the United States, the report is misleading without a 

greater state perspective. Despite their small size, some State programs have substantial 

competency in the area of radon measurement reliability, and we suggest the OIG report would 

be considerably more robust if the State program perspective were to be included. 

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Responsibility for quality control and assurance is shared among EPA, States, private 

proficiency programs, device manufacturers, and laboratories. The OIG report recognizes that 

limited resources are a constraint throughout the system, and that is a key insight. The US radon 

protection system as a whole operates on the basis of high professional commitment and modest 

resources. Although competent and dedicated, State radon programs are typically very small. 

Private proficiency programs, field mitigators, device manufacturers, and test labs operate within 

tight financial margins. The current economic crisis has put additional strain on a system already 

under daily pressure. Device testing, quality assurance activities, and more exotic system 

checks, such as blind testing, are especially costly to an industry operating in such difficult 

market circumstances. 

See Appendix B, Note 2, for OIG Response 

Further, the report does not acknowledge that different levels of measurement precision 

are appropriate for different applications. For residential self-testing, devices must not only 

guide appropriate personal decisions about actions to reduce residential risk, but must also be 

broadly available, affordable, and easy to use by the non-expert. More accurate measurement is 

available for specific applications (long-term tests, active devices, etc.) when their greater cost is 

justified. Cheap, simple devices that build awareness and motivate action are indispensible, even 

at the price of some scientific accuracy. 

See Appendix B, Note 3, for OIG Response 

Another important consideration not adequately addressed by OIG is that EPA’s 

recommended action level of 4 pC/L does not demark a bright line between “healthy” and 

“unhealthy.” As EPA acknowledges in our public documents, a great deal of risk persists below 

the action level. EPA’s level is based on practical considerations, such as ease of measurement 

and the likelihood that standard methods of mitigation will result in substantial risk reduction if 

undertaken at or above the recommended action level. Since the action level is itself imprecise, 

the burden on testing to measure precisely against it is not so great as it would otherwise be. In 

that respect, we note, as does OIG, that the Canadian government recently established a standard 

of accuracy for measurement of radon in air (-33/+50%) that is significantly broader than the 

guideline adopted by EPA for use in its former National Radon Proficiency Program (+/-25%). 

The Canadian action is consistent with EPA’s view that precision in measurement is less 

important than offering a test that is simple, affordable, and effective in driving individual action 

to reduce high levels of indoor radon. 

See Appendix B, Note 4, for OIG Response 

Despite such constraints, EPA and the radon community have taken numerous steps to 

address device accuracy, and the report would benefit from their inclusion. EPA’s Radon 

Laboratory at the Radiation and Indoor Environments National Laboratory (R&IE) plays an 

active role in assisting the national proficiency programs in their efforts to ensure reliability and 

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accuracy of the radon measurement industry. For the past several years, the R&IE has provided 

verification exposures of radon measurement devices for both NEHA and NRSB. The lab also 

supports performance testing of commercial radon laboratories and calibration of Lucas type 

cells for the measurement of radon gas. More recently the R&IE Laboratory has begun to 

support university researchers and State organizations conducting blind testing of commercially 

available radon measurement devices. 

In addition, the stakeholder dialogue group convened by EPA – which is actually a venue 

for communication and problem-solving and not a “consensus building process” as it is 

characterized in the report – has worked to address device accuracy. The group has examined 

QA/QC needs for radon protection, and national consensus groups such as ASTM and the Radon 

Consortium have subsequently formed committees and begun work on writing and revising 

quality standards for the industry. The dialogue group continues to discuss opportunities for 

greater focus and consistency in radon testing and measurement. Also, the annual National 

Radon Training Conference and International Radon Symposium has scheduled numerous 

technical sessions and produced several professional papers addressing device accuracy. Finally 

several parties have undertaken blind testing projects, some of which OIG reviewed. The State 

of Pennsylvania, for example, has conducted several blind testing studies that were not discussed 

in the OIG review. 

See Appendix B, Note 5, for OIG Response 

While such undertakings do not constitute a unified national system of device 

testing and measurement, they reflect the radon community’s shared concern with verifying and 

improving measurement accuracy appropriate to the application. The renewed attention brought 

by the OIG to this need is therefore welcome, and OAR believes it will generate even further 

commitment to continued improvement in a vital area of the radon program. 

Recommendation 2 - Inform Congress that the limitations of reliable testing for radon may 

negatively affect achieving the IRAA goals. 

OAR concurs with this recommendation. OIG recommended in a previous evaluation 

that we use the Performance and Accountability Report to inform Congress of issues raised in 

that report. OAR will work with OCFO to include this recommendation in that process and will 

initiate updating the PAR within 90 days of the final OIG report. 

See Appendix B, Note 6, for OIG Response 

Thank you again for the opportunity to comment on the draft evaluation report. If you 

have questions, please contact Bill Long, Director for the Center of Radon and Air Toxics, at 

(202) 343-9733. 

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 Appendix B 

OIG Evaluation of Agency Response 

Note 1 - We agree with the Agency’s commitment to review its public materials and revise 

them, as appropriate. However, the Agency did not provide information related to 

what they will disclose, such as whether public materials will explicitly state that 

commercially available radon testing devices and radon testing laboratories may not 

be accurate and reliable. Additional information is needed to assess whether EPA’s 

planned actions meet the intent of this recommendation. The recommendation will 

remain open and unresolved until an Agency corrective action plan is completed that 

provides details on how the Agency will implement the recommendation. 

Note 2 - We do not believe our report is misleading. Our objectives were to determine how 

EPA ensures that radon testing devices and laboratories accurately analyze and report 

indoor radon results. We saw no systemic program or process for doing this. While 

some States may provide oversight activities, as discussed on page 4 of this report, 

there are variances in State oversight activities. For example, if a proficiency 

program decided to remove a radon testing device from its list of certified devices, 

the vendor could still operate in States that do not have certification requirements. 

Further, as we noted in our June 2008 report, More Action Needed to Protect Public 

from Indoor Radon Risks (Report No. 08-P-0174), radon codes and regulations vary 

widely between locations, even within States. 

Note 3 - The Agency states that our report does not acknowledge that different levels of 

measurement precision are appropriate for different applications. We do not agree with 

the Agency’s premise. As we noted in our June 2008 report, there is no safe level of 

exposure to radon gas, and the only way to know whether indoor radon levels are elevated is 

to test the indoor air. However, testing with inaccurate, unreliable devices may or may not 

“. . . build awareness and motivate action,” as stated in the Agency’s response. Device 

readings that overstate the true level of risk may cause homeowners to take unnecessary 

actions, and readings that understate the true level of risk may cause homeowners to 

forego taking needed actions. 

Note 4 - We clarified our description of EPA’s action level in response to the Agency’s 

concern regarding how we characterized this in the draft report. 

Note 5 - We revised the description of the stakeholder dialogue group convened by EPA to 

state that it is a venue for communication and problem-solving and, according to 

EPA, has worked to address device accuracy. Regarding the Agency’s statement that 

Pennsylvania has conducted several blind testing studies that were not included in the 

OIG review, we followed up with the Office of Air and Radiation and obtained two 

studies conducted by the Pennsylvania Department of Environmental Protection, 

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Bureau of Radiation Protection.6 The two studies address the blind testing of 

laboratories certified to provide radon results in Pennsylvania. These studies do not 

contradict our conclusion regarding EPA’s ability to assure the public about radon 

test results because these studies also identified instances of inaccurate test results. 

Also, neither study addresses the accuracy and reliability of radon test kits. We 

acknowledge that Pennsylvania's Department of Environmental Protection reported 

improvements in laboratory testing. However, as discussed in Note 2, there are 

variances in State codes, regulations, and oversight activities. Pennsylvania supports 

a certified radon testing program, which performs regular inspections of laboratories. 

As stated in the 2003 study: 

The higher percentage pass rate for this study may reflect lessons 

learned and good practices incorporated and better attention to quality 

assurance procedures. The better attention to good QA [quality 

assurance] procedures may be due to the fact that this state radon 

program performs regular inspections of testers and laboratories. 

EPA acknowledges in its response that it does not oversee a comprehensive national 

system of quality assurance for the testing and certification of radon measurement 

devices and laboratories in the United States. 

Note 6 - The Agency’s response meets the intent of our recommendation. The 

recommendation will remain open until the Agency provides an acceptable action 

plan that includes a completion date. 

6 Short-Term Electret Ion Chamber “Blind” Testing Program," Lewis, Robert K., Pennsylvania Department of 

Environmental Protection, Bureau of Radiation Protection, Radon Division, Harrisburg, Pennsylvania, included 

in the "Proceedings of the 2003 International Radon Symposium - Volume II, American Association of Radon 

Scientists and Technologists, Inc., October 5-8, 2003; and "Blind Testing of Certified Charcoal Laboratories" 

by Lewis, Robert K, Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection, 

Radon Division, Harrisburg, Pennsylvania, June 2005. 

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Appendix C 

Distribution 

Office of the Administrator 

Acting Assistant Administrator for Air and Radiation 

Deputy Assistant Administrator for Air and Radiation 

Director, Office of Radiation and Indoor Air 

Agency Follow-up Official (the CFO) 

Agency Follow-up Coordinator 

Acting General Counsel 

Acting Associate Administrator for Congressional and Intergovernmental Relations 

Acting Associate Administrator for Public Affairs 

Audit Follow-up Coordinator, Office of Air and Radiation 

Acting Inspector General 

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