&EPA
United States
Environmental Protection
Agency
Air and Radiation
(6609J)
EPA402-R-92-014
July 1993
Radon Measurement
In Schools
Revised Edition
Aa Bb Cc Dd Ee
-------
TABLE OF CONTENTS
SECTION!: INTRODUCTION
A. Radon Facts
B. Health Effects
C. Radon Exposure
D. The Radon Problem in Schools
E. Radon Entry into Schools
SECTION II: RADON TESTING IN SCHOOLS
A. Introduction
B. Measurement Strategy for Schools
C. What Rooms to Test
D. When to Conduct Radon Measurements
E. Who May Conduct Testing
F. Quality Assurance Measurements
G. Summary of EPA Recommendations
H. Deciding How Quickly to Mitigate
I. Decision-Making Flow Chart
SECTION III: REDUCING RADON CONCENTRATIONS
SECTION IV: FREQUENTLY-ASKED QUESTIONS
A. Radon and Radiation
B. Planning and Testing
C. Conducting Initial Measurements
D. Tampering/Detector Placement
E. Weather Conditions
F. Conducting Follow-up Measurements
F. Quality Assurance
APPENDICES
A. State/Indian Nation Radon Contacts
B. EPA Regional Offices and Radon Training Centers
C. Using a Measurement Service
D. Measurement Devices
E. Quality Assurance Procedure
F. Procedural Checklist for Radon Testing
2
2
4
4
5
6
7
9
10
12
14
16
16
16
18
20
20
22
24
24
25
25
27
28
29
32
34
37
40
-------
Note; EPA no longer updates this information, but it may be
useful as a reference or resource,
Corrections in the Second Printing
page 9 After the third bullet in the subsection on Retesting, the following
bullet has been added:
• Retest after major renovations to the structure of a school building or
after major alterations to a school's HVAC system. These
renovations and alterations may increase radon levels within a
school building.
page 10 For the subsection on Recommendations for Specific School
Designs, the recommendations for a school with a Basement
Design has been further clarified:
(Original)
Basement Design: In addition to measuring all frequently occupied
basement rooms, measure all rooms above the basement that have
at least one wall with substantial contact with the ground.
(Clarification)
Basement Design: In addition to measuring all frequently occupied
basement rooms and rooms with a floor or wall with ground-
contact, measure all rooms that have no ground-contact but that
are directly above a basement space that is not frequently-
occupied.
page 19 For the subsection on Active Sub-slab Depressurization, the sixth
line of the first paragraph has been corrected to read:
(Original)
... When radon levels are greater than 20 pd/L..
(Correction)
...When radon levels are greater than 10 pCi/L...
-------
FOR FURTHER INFORMATION
Radon Measurement in Schools: Self-Paced Training Workbook
(EPA402-B-94-001)
For a free copy, call 202-260-2080 or write to the US EPA Public
Information Center; 401 M. Street, SW(PM 211 B); Washington, DC
20468. Please include your name, address, title of the document, and the
EPA number for the document. Before testing, call your State Radon Contact
for information on any State requirements concerning radon testing in schools
and on available state training.
Reducing Radon in Schools: A Team Approach
(EPA 402-R-94-OOB)
For a free copy, call your State Radon Contact.
Radon Prevention in the Design and Construction of Schools and Other
Large Buildings
(EPA625-R-92-016)
For a free copy, call the Center for Environmental Research Information at
513-569-7562 or FAX your request to 513-569-7566. Please include your
name, address, title of the document, and the EPA number for the document.
-------
SECTION I: INTRODUCTION
The U.S. Environmental Protection Agency (EPA) and other major national and
international scientific organizations have concluded that radon is a human carcinogen
and a serious environmental health problem. Early concern about indoor radon focused
primarily on the hazard posed in the home. More recently, the EPA has conducted
extensive research on the presence and measurement of radon in schools. Initial
reports from some of those studies prompted the Administrator in 1989 to recommend
that schools nationwide be tested for the presence of radon. Based on more recent
findings, EPA continues to advise U.S. schools to test for radon and to reduce levels to
below 4 pCi/L.
This report has been prepared to provide school administrators and facilities
managers with instructions on how to test for the presence of radon. The findings from
EPA's comprehensive studies of radon measurements in schools have been
incorporated into these recommendations. This report supersedes Radon
Measurements in Schools-An Interim Report (EPA 520/1-89-010). However, it does
not invalidate tests conducted or tests in the process of being conducted under the
interim report.
The amount of radon gas in the air is measured in picocuries per liter of air or
pCi/L. However, sometimes test results are expressed in Working Levels (WL),
representing radon decay products. EPA recommends that schools take action to
reduce the level of radon when levels are 4 pCi/L (or 0.02 WL) or higher. Testing is the
only way to determine whether or not the radon concentration in a school room is below
the action level. Measuring levels of radon gas in schools is a relatively easy and
inexpensive process compared to many other important building upkeep activities.
Because radon levels in schools have been found to vary significantly from room
to room, schools should test all frequently occupied rooms in contact with the ground. If
a room is found to have a level of 4 pCi/L or greater, this measurement result should be
confirmed with another test. If the second test is also at or above 4 pCi/L, schools
should take action to reduce the radon level to below 4 pCi/L.
Page 1
-------
In addition to radon, some schools may be interested in addressing overall
indoor air quality concerns. Many schools have poor indoor air quality resulting in part
from low rates of ventilation (low outdoor air intake). This is often the result of poor
maintenance and improper operation of the HVAC system or limiting the intake of
outdoor air to reduce heating (and cooling) costs. EPA is preparing to release practical
guidance on improving indoor air quality in school buildings. The guidance entitled
Indoor Air Quality Tools for Schools will be available in early 1995 through the
Superintendent of Documents; P.O. Box 371954; Pittsburgh, PA 15250-7954.
A. RADON FACTS
Radon is a naturally occurring radioactive gas. It comes from the natural
breakdown (decay) of uranium which is found in soil and rock allover the United States.
Radon travels through soil and enters buildings through cracks and other holes in the
foundation. Eventually, it decays into radioactive particles (decay products) that can
become trapped in your lungs when you breathe. As these particles in turn decay, they
release small bursts of radiation. This radiation can damage lung tissue and lead to lung
cancer over the course of your lifetime. EPA studies have found that radon
concentrations in outdoor air average about 0.4 pCi/L. However, radon and its decay
products can accumulate to much higher concentrations inside a building.
Radon is colorless, odorless, and tasteless. The only way to know whether or
not an elevated level of radon is present in any room of a school is to test. Each
frequently occupied room that is in contact with the ground should be measured
because adjacent rooms can have significantly different levels of radon.
B. HEALTH EFFECTS
Radon is a known human carcinogen. Prolonged exposure to elevated radon
concentrations causes an increased risk of lung cancer. Like other environmental
pollutants, there is some uncertainty about the magnitude of radon health risks.
However, scientists are more certain about radon risks than risks from most other
Page 2
-------
cancer-causing environmental pollutants. This is because estimates of radon risk
are based on studies of cancer in humans (underground miners). Additional studies on
more typical populations are underway.
EPA estimates that radon may cause about 14,000 lung cancer deaths in the
U.S. each year. However, this number could range from 7,000 to 30,000 deaths per
year. The U.S. Surgeon General has warned that radon is the second-leading cause
of lung cancer deaths. Only smoking causes more lung cancer deaths. The following
bar chart displays the estimated deaths caused by radon relative to deaths resulting
from other causes. The numbers of deaths from other causes are taken from 1990
National Safety Council Reports.
30,000
Radon is
estimated
to cause
thousands of
cancer deaths
in the U.S.
each year.
deaths
per year
10,000
Drunk RADON Drownings Fires Airline
Driving Crashes
Not everyone who breathes radon decay products will develop lung cancer. An
individual's risk of getting lung cancer from radon depends mostly on three factors: the
level of radon, the duration of exposure, and the individual's smoking habits. Risk
increases as an individual is exposed to higher levels of radon over a longer period of
time. Smoking combined with radon is an especially serious health risk. The risk of
dying from lung cancer caused by radon is much greater for smokers than it is for non-
smokers.
Children have been reported to have greater risk than adults for certain types of
cancer from radiation, but there are currently no conclusive data on whether children
are at greater risk than adults from radon.
Page 3
-------
C. RADON EXPOSURE
Because many people - particularly children - spend much of their time at home,
the home is likely to be the most significant source of radon exposure. Parents are
strongly encouraged to test their homes for radon and to take action to reduce elevated
radon concentrations there. Information to assist them in such efforts is provided in
EPA's A Citizen's Guide to Radon (EPA 402-K92-001, May 1992).
For most school children and staff, the second largest contributor to their radon
exposure is likely to be their school. As a result, EPA recommends that school
buildings as well as homes be tested for radon.
EPA recommends reducing the concentration of radon in the air within a school
building to below EPA's radon action level of 4 pCi/L. EPA believes that any radon
exposure carries some risk - no level of radon is safe. Even radon levels below 4 pCi/L
pose some risk, and the risk of lung cancer can be reduced by lowering radon levels.
This action level is based largely on the ability of current technologies to reduce
elevated radon levels below 4 pCi/L. Depending on the building characteristics, radon
levels in some schools can be reduced well below 4 pCi/L. In other schools, reducing
radon levels to below 4 pCi/L may be more difficult.
D. THE RADON PROBLEM IN SCHOOLS
EPA's investigations of radon in schools were initiated in 1988 with a study of
schools in Fairfax County, Virginia. Findings from that study were used to develop the
Radon Measurement in Schools - An Interim Report (EPA 520/1 -89- 010). Schools
have been using this document as a interim guide for measuring radon in schools.
In 1989 and 1990, EPA conducted the School Protocol Development Study,
a nationwide effort to further examine how best to conduct radon measurements in
schools. Results from this study have been used to improve the procedures for testing
radon in schools and are incorporated into this document.
The results of this study also suggested that elevated radon levels (levels > 4
pCi/L) may exist in at least some schools in every state. Although most elevated
measurements in this study were slightly greater than 4 pCi/L, several schools were
found with levels well over 20 pCi/L while some have been found with concentrations
over 100 pCi/L.
Page 4
-------
EPA has conducted a National School Radon Survey which provides a
statistically valid representation of the levels of radon in schools at the national level but
not at the state or local level. The results show widespread radon contamination in
schools. EPA estimates that 19.3% of U.S. schools, nearly one in five, have at least
one frequently occupied ground contact room with short-term radon levels above 4
pCi/L - the level at which EPA recommends mitigation. In total, EPA estimates that over
70,000 schoolrooms in use today have short-term radon levels above 4 pCi/L. Refer to
your State Radon Contact or EPA Regional Office for further information about the
results of this surveyor for more information about radon in schools in your area (see
Appendix A and B).
E. RADON ENTRY INTO SCHOOLS
Many factors contribute to the entry of radon gas into a school building. Schools
in nearby areas can have significantly different radon levels from one another. As a
result, school officials can not know if elevated levels of radon are present without
testing. The following factors determine why some schools have elevated radon levels
and others do not:
» the concentration of radon in the soil gas (source strength) and permeability
of the soil (gas mobility) under the school;
» the structure and construction of the school building; and
» the type, operation, and maintenance of the heating, ventilation, and air-
conditioning (HVAC) system.
Many schools are constructed on adjoining floor slabs which permit radon gas to
enter through construction and expansion joints between the slabs. Other features, such
as the presence of a basement area, crawl spaces, utility tunnels, subslab HVAC ducts,
cracks, or other penetrations in the slab (e.g., around pipes) also provide areas for
radon to enter indoor spaces.
Depending on their design and operation, HVAC systems can influence radon levels in
schools by:
» increasing ventilation (diluting indoor radon concentrations with outdoor air);
» decreasing ventilation (allowing radon gas to build up); pressurizing a building
(keeping radon out); and,
Page 5
-------
» depressurizing a building (drawing radon inside).
The frequency and thoroughness of HVAC maintenance can also play an
important role. For example, if air intake filters are not periodically cleaned and
changed, this can significantly reduce the amount of outdoor air ventilating the indoor
environment. Less ventilation allows radon to build-up indoors.
An understanding of the design, operation, and maintenance of a school's HVAC
system and how it influences indoor air conditions is essential for understanding and
managing a radon problem as well as many other indoor air quality concerns in schools.
More information on how HVAC systems can affect school radon concentrations is
provided in SECTION III.
SECTION II: RADON TESTING IN SCHOOLS
A. INTRODUCTION
There are two general ways to test for radon:
1. A short-term test is the quickest way to test for radon. In this test, the testing
device remains in an area (e.g., schoolroom) for a period of 2 to 90 days
depending on the device. Because radon levels tend to vary from day to day and
from season to season, a short-term test is less likely than a long- term test to
give an average radon level for a school year.
2. A long-term test remains in place for more than 90 days. A long-term test (e.g.,
a test conducted over the school year) will give a result that is more likely to
represent the school year average radon level in a schoolroom than a short-term
test.
Short-term measurements are most often made with activated charcoal devices,
alpha track detectors, electret-ion chambers, continuous monitors, and charcoal liquid
scintillation detectors. Alpha track detectors and electret-ion chambers are used for
long-term tests. Some general information about radon detectors is given in Appendix
D. More detailed information can be found in the document entitled Indoor Radon and
Radon Decay Product Measurement Device Protocols (EPA-402-R-92-004). In order to
assure adequate test results, only devices that are used for a measurement period of at
least 48 continuous hours should be used when testing for radon in school buildings.
Page 6
-------
Of the short-term tests, a 90-day test may provide a more representative picture
of the average school year radon level in a schoolroom than 2 to 5-day tests. Long-
term tests are able to integrate fluctuations of radon concentrations with time. For
example, while a 2-day radon measurement might be made during a period of higher
than usual radon levels, a 90-day measurement will allow such highs, if they are
occurring, to be balanced by periods of moderate or low radon concentrations.
Alternatively, 2 to 5-day tests indicate the radon level for a shorter period of
testing during which radon levels may have been somewhat higher or lower than the
school year average. However, EPA research suggests that, on average, these
measurements are more likely to reflect the average radon level for a 3-month or longer
period when testing is conducted in the coldest months of the year when closed
conditions are more likely to be present [see SECTION II (D) below].
B. MEASUREMENT STRATEGY FOR SCHOOLS
If a school decides to use a short-term test during initial measurements, EPA
recommends the two-step approach described below.
Step 1 Initial Measurements
Take initial measurements using a short-term test. Short-term measurements
should be made in all frequently occupied rooms in contact with the ground to
provide a quick test of whether or not high radon concentrations are present. All rooms
should be tested simultaneously.
» Do a follow-up test in every room with a short-term, initial test result of 4 pCi/L
or greater (See Step 2).
Step 2 Follow-up Measurements
All follow-up measurements in a school should be conducted simultaneously.
Follow-up measurements should be made in the same locations and under the same
conditions as the initial measurements (to the extent possible, including similar seasonal
conditions and especially HVAC system operation). This will ensure that the two results
are as comparable as possible.
» Use a short-term, follow-up test if results are needed quickly.
The higher the initial short-term test result, the more certain you can be that a
short-term test should be used rather than a long-term follow-up test. In general,
Page 7
-------
the higher the initial measurement, the greater the urgency to do a follow-up test as
soon as possible. For example, if the initial short-term measurement for a room is
several times the EPA's radon action level (e.g., about 10 pCi/L or higher), a short-term
follow-up measurement should be taken immediately.
» Use a long-term, follow-up test to better understand the average radon level
for a school year.
When a room's initial result is only slightly elevated above 4 pCi/L (e.g., between
4 and 10 pCi/L), a long-term follow-up measurement -preferably taken over the entire
nine month school year - is appropriate. The result from such a test may best represent
the average radon concentration for the school year in that room. A long-term test
should be conducted over the school year immediately following the completion of initial
measurements.
Appendix F provides a list of steps to take during a radon-testing program.
These steps are not intended to be all-inclusive. However, they may serve as guide
through the process of radon testing in a school.
Interpreting Test Results
» If a short-term, follow-up measurement was used, take action to reduce the
radon level if the average of the initial and follow-up measurement results is 4
pCi/L or more.
» If the result of a long-term, follow-up measurement is 4 pCi/L or more, take
action to reduce radon levels.
Schools can reduce radon levels by proceeding with diagnostics and mitigation.
Diagnostics involve the evaluation of radon entry points and the identification of the
appropriate radon reduction technique. Mitigation is the design and implementation of a
radon reduction system. Reducing Radon in Schools: A Team Approach (EPA 402-R-
94-008) will assist schools with the mitigation process. To receive this document, call
your State Radon Contact or EPA Regional Office (See Appendix A and B). For more
information on reducing radon concentrations in schoolrooms see SECTION III.
EPA does not recommend that schools use a single short-term test as the
basis for determining whether or not action needs to be taken to reduce radon
levels. A follow-up measurement to confirm an initial short-term measurement of 4
pCi/L or higher should be conducted before making such a decision. Indoor radon
levels depend upon a number of variables and can fluctuate significantly from day to
day. Short-term tests (particularly tests of 2 to 5-days) may in some cases reflect an
unusual peak in the radon concentration thus indicating a need for remedial action
Page 8
-------
which may not be necessary. In addition, EPA studies have shown that the averaging of
two such short-term measurements reduces the possibility of misrepresenting the
average radon concentration.
Retesting
In addition to initial and follow-up measurements, EPA recommends that schools
retest sometime in the future especially after significant changes to the building
structure or the HVAC system. Suggested times for retesting are as follows:
» If no mitigation is required after initial testing (e.g., all rooms were found to
have levels below 4 pCi/L), retest all frequently occupied rooms in contact
with the ground sometime in the future. As a building ages and settles, radon
entry may increase due to cracks in the foundation or other structural
changes.
» If radon mitigation measures have been implemented in a school, retest these
systems as a periodic check on any implemented radon reduction measures.
» If major renovations to the structure of a school building or major alterations
to a school's HVAC system are planned, retest the school before initiating the
renovation. If elevated radon is present, radon-resistant techniques can be
included as part of the renovation.
» Retest after major renovations to the structure of a school building or after
major alterations to a school's HVAC system. These renovations and
alterations may increase radon levels within a school building.
C. WHAT ROOMS TO TEST
EPA's research in schools has shown that radon levels often vary greatly from
room to room in the same building. A known radon measurement result for a given
classroom cannot be used as an indicator of the radon level in adjacent rooms.
Therefore, EPA recommends that schools conduct initial measurements in all frequently
occupied rooms in contact with the ground.
Frequently occupied rooms are usually classrooms, offices, laboratories,
cafeterias, libraries, and gymnasiums. Areas such as rest rooms, hallways, stairwells,
elevator shafts, utility closets, and storage closets need not be tested
(Note: these areas may be important areas for diagnostic testing if elevated radon is
found). EPA studies indicate that radon levels on upper floors are not likely to
Page 9
-------
exceed the levels found in ground-contact rooms. Testing rooms on the ground-contact
floor is sufficient to determine if radon is a problem in a school.
Recommendations for Specific School Designs
Slab-on-Grade Design: Measure only frequently occupied rooms in contact with
the ground.
Open-Plan or Pod Design: If sections of a pod have moveable walls that can
physically separate them from other sections, measure each section separately.
If moveable walls are absent or inoperable, measure the pod as one room
placing detectors every 2000 square feet.
Crawl Space Design: If classrooms are above an enclosed crawl space, measure
rooms directly above the crawl space.
Basement Design: In addition to measuring all frequently occupied basement
rooms and rooms with a floor or wall with ground-contact, measure all rooms that
have no ground-contact but that are directly above a basement space that is not
frequently occupied.
Placing Detectors in a Room
» Do not place detectors near drafts resulting from heating, ventilating vents, air
conditioning vents, fans, doors, and windows.
» Place detectors where they are least likely to be disturbed or covered up.
» Do not place detectors in direct sunlight or in areas of high humidity.
» Place detectors at least approximately 50 centimeters (20 inches), from the
floor and 10 centimeters (4 inches) from other objects and away from the
exterior walls of the building.
» Place detectors about every 2,000 square feet for large spaces.
» Do not disturb the test device at any time during the test.
Page 10
-------
D. WHEN TO CONDUCT RADON MEASUREMENTS
Recommendations
The purpose of initial testing is to identify rooms that have a potential for elevated
radon levels (e.g., levels of 4 pCi/L or greater) during the school year. To achieve this
purpose, EPA recommends that initial measurements be conducted:
» under closed conditions (closed windows/doors except for normal exit/entry).
» after 12-hours of closed conditions when using a 2 to 5-day test (e.g., initiate
testing after a weekend).
» during colder months (October through March, depending on geographical
location).
» during weekdays with HVAC systems operating normally when conducting a
2 to 5-day test.
The EPA recommends that schools avoid conducting initial measurements under
the following conditions:
» during abnormal weather or barometric conditions (e.g., storms and high
winds).
» during structural changes to a school building and/or the renovation or
replacement of the HV AC system.
An Explanation of the Recommendations
Closed conditions: Short-term tests should be made under closed conditions in
order to obtain more representative and reproducible results. Open windows and doors
permit the movement of outdoor air into a room. When closed conditions in a room are
not maintained during testing, the subsequent dilution of radon gas by outdoor air may
produce a measurement result that falls below the action level in a room that actually
has a potential for an elevated radon level. Closed conditions should be maintained for
at least 12-hours prior to the start of 2 to 5-day measurements. When using a short-
term test of 90-days, schools should also maintain closed conditions to the extent
possible. Although brief periods of open windows will not seriously jeopardize the
results, they should be avoided during testing.
Page 11
-------
Colder months: Because testing under closed conditions is important to obtain
meaningful results from short-term tests, schools should schedule their testing during
the coldest months of the year. During these months, windows and exterior doors are
more likely to be closed. In addition, the heating system is more likely to be operating.
This usually results in the reduced intake of outside air. Moreover, EPA has studied
seasonal variations of radon measurements in schools and found that short-term
measurements may more likely reflect the average radon level in a room for the school
year when taken during the winter heating season.
Weekday testing: When using 2 to 5-day short-term tests, EPA recommends that
testing be conducted on weekdays with HVAC systems operating normally. This
approach has the important advantage of measuring radon levels under the typical
weekday conditions for that school. This also eliminates the burden of weekend testing
and non-routine adjustments to the HVAC systems as previously recommended in
EPA's interim school guidance. Based upon EPA studies, this recommendation to
conduct 2 to 5-day tests on weekdays does not invalidate radon measurements that
were conducted on weekends with HVAC system operating continuously as
recommended in the interim school guidance (See SECTION IV (B), page 22).
Weather conditions: If major weather or barometric changes are expected, EPA
recommends postponing 2 to 5-day testing. EPA studies show that barometric
changes affect indoor radon concentrations. For example, radon concentrations can
increase with a sudden drop in barometric pressure associated with storms.
E. WHO MAY CONDUCT TESTING
Introduction
There are two options that EPA recommends to school officials when testing their
school for radon:
» testing may be conducted by a measurement service that has demonstrated
proficiency in EPA's Radon Measurement Proficiency (RMP) Program.
» testing may be conducted by qualified, trained school personnel.
Schools may choose to hire a testing service to supervise and conduct initial and
follow-up measurements. EPA operates a voluntary program to ensure that radon
measurement services with their selected test devices provide quality test results. This
program is called the Radon Measurement Proficiency (RMP) Program. EPA
recommends that schools use only RMP-listed (or State-listed) companies for
Page 12
-------
radon measurement services. Call your State Radon Contact or EPA Regional Office
for more information. General guidelines to consider when hiring a company to perform
school radon testing are given in Appendix C.
School and school district personnel may choose to design and implement the
radon testing program themselves if they are willing to devote the needed effort to
achieve a successful testing program. Radon testing requires careful planning, record
keeping, and logistical preparation which requires attention to the selection of
appropriate test locations and the handling of large numbers of devices. This option
has the advantages of reducing costs and providing in-house experience and
awareness to address future radon needs (e.g., such as retesting).
EPA recommends that school personnel use only radon testing devices from a
company listed with EPA's RMP Program or your State. EPA also recommends that
school personnel receive training to ensure the quality of their work when electing to do
testing themselves.
Recommended level of Training
EPA recommends two different levels of training for school personnel depending
on the measurement method chosen:
» Use of devices that are returned to a RMP-listed laboratory for determination
of the test result. In this case, school personnel are not involved in
determining the level of radon in pCi/L (or in WL) that is present in a room.
For most devices, the purchase price generally includes payment for the
laboratory analysis. For others, an additional fee may be charged when the
device is returned to the laboratory.
School personnel using devices which will be analyzed by an RMP-listed service
should receive training to introduce them to the major components of a school testing
program. At a minimum, school personnel who will supervise the measurement process
should receive training, but demonstrated proficiency in the RMP is not necessary.
» Use of devices purchased from a RMP-listed company where the
measurement in pCi/L or WL can be determined directly from the device with
either special portable equipment or directly from a self-contained
measurement device. In this case, school personnel are able to measure
directly the radon concentration and determine the test result immediately
(i.e., without a RMP-listed laboratory).
EPA strongly recommends that school personnel who plan to use measurement
devices or equipment which provide immediate results (i.e., the radon level)
Page 13
-------
demonstrate proficiency in the RMP Program or a State Certification Program.
Alternatively, school personnel could be directly supervised by someone who is RMP-
listed (e.g., State officials). Because school personnel, rather than an RMP- listed firm,
are providing the measurement analysis, EPA believes that it is important that these
school personnel demonstrate proficiency in the measurement of radon via the RMP. A
certain level of technical knowledge and demonstrated capability is necessary to ensure
the quality of such test results.
EPA recommends that you call your State Radon Contact for more information
on available training and for information on any state requirements before you begin to
test your school (see Appendix A). EPA supports several regional Radon Training
Centers (RTC) that currently provide courses in radon measurement, diagnostics, and
mitigation including courses associated with the Radon Measurement Proficiency
Program. EPA and the RTCs have also developed self-instructional training for radon
testing in schools. This training is presented in the document Radon Measurement in
Schools: Self-Paced Training Workbook (EPA 402-8-94-001). For directions on how to
obtain this workbook, refer to the box containing further information located at the
beginning of this document.
F. QUALITY ASSURANCE MEASUREMENTS
To ensure that measurement results are reliable, EPA strongly recommends that
quality assurance measurements accompany initial and follow-up measurements. The
term quality assurance refers to maintaining minimum acceptable standards of
precision and accuracy in your testing program. Quality assurance measurements
include side-by-side detectors (duplicates) and unexposed control detectors (blanks).
Appendix E provides the procedure to help you evaluate the results of the quality
assurance measurements.
Assessing the Precision of Your Measurements
Duplicates are pairs of detectors deployed in the same location side-by-side for
the same measurement period. Duplicates should be placed in 10 percent of all
measurement locations in a school building (they need not exceed 50 extra detectors).
They are stored, deployed, placed, removed, and shipped to the laboratory for analysis
in the same manner as the other devices so that the processing laboratory cannot
distinguish them.
Since duplicates are placed side-by-side, the measured values for radon should
be the same. For duplicate pairs where the average of the two measurements is
greater than or equal to 4 pCi/L, they should not differ by more than 25%. If they do,
each measurement is questionable. Problems in handling the detectors during the
measurement process, in the laboratory analysis, or in the detector may
Page 14
-------
introduce error into the test results. Consistent failure in duplicate agreement should be
investigated.
Assessing the Accuracy of Your Measurements
Blanks can be used to determine whether the manufacturing, shipping, storage,
or processing of the detector has affected the accuracy of your measurements. They
are called "blanks" because they are not deployed in a room during the measurement
period. As a result, blanks should give a result at or near to 0.0 pCi/L. Blanks are
unwrapped (but not opened) and immediately rewrapped at the end of the exposure
period. They are then shipped with the exposed devices so that the laboratory cannot
distinguish the two sets of devices. The number of blanks should be 5% of the
detectors deployed or 25 whichever is less.
Since blanks are not exposed to radon, their measurement value should
theoretically be 0.0 pCi/L. Any value other than 0.0 is a measure of the accuracy of
your measurements. For example, if a blank yields a result of 2 pCi/L, this indicates
some problem with the measurement device or the laboratory analysis.
G. SUMMARY OF EPA RECOMMENDATIONS
» Initial short-term tests should be made in all frequently occupied, ground-
contact rooms.
» Initial testing should be conducted during the coldest months when the
heating system is operating and windows and doors are closed (except for
normal exit/entry).
» If a school uses a short-term test of 2 to-5 days, the tests should be
conducted on weekdays with the HVAC system operating normally.
» If the short-term test shows that the radon level in a room is 4 pCi/L or
greater, schools should conduct either a second short-term test or a long-
term test to confirm the presence of an elevated radon level.
» EPA does not recommend that schools use a single short-term test result as
the basis for determining if action needs to be taken to reduce radon levels.
» Duplicates and blanks should accompany all testing programs (conducted by
school personnel or a measurement firm) to provide assurance of the quality
of the measurements.
Page 15
-------
Trained school personnel or a RMP-listed measurement service should
supervise and/or conduct a radon-testing program.
H. DECIDING HOW QUICKLY TO MITIGATE
How quickly to begin the diagnostic measurements that precede mitigation will
depend on the urgency of the situation as dictated by the radon level detected. Very
elevated radon concentrations (e.g., several times the action level or around 10 pCi/L)
demand a quicker response. In addition, if radon levels are near 100 pCi/L or greater,
school officials should call their State Radon Contact and consider relocating until the
levels can be reduced.
I. DECISION-MAKING FLOW CHART
The decision-making flow chart on the following page summarizes the t testing
guidelines from initial measurements through the decision to mitigate.
Page 16
-------
to in all
the
of the
Short-term
the of the
in on tie of
the
For
> 10 pCi/L),
a
Long-term
Do the
In the
as the
(if
fie
season.
Confirm a 9-month
the
the
/""^ ^\
<^ the .
N\^ *^
j YES
and a
The the
the
the for
1________
HO
*v
X" '"' " " - . -
HL
Considc
- ~~ ~ ~~ "" • mire
-
xx \,
/Is the \
NO ^,s v
""^x _^ •'"
"\ 2: 4 pCi/L?, ,•'"
fvES
a
The the
the
for
^^^JZIIIIT^^^
' f
jr
j
-------
SECTION III: REDUCING RADON CONCENTRATIONS
Introduction
EPA has investigated schools with elevated radon levels nationwide. These
investigations indicate that school buildings are more complex in their construction and
operation than most houses. As a result, diagnostic measurements are necessary to
develop and implement an appropriate mitigation strategy. In addition, these
investigations indicate that the following two strategies are effective in school buildings:
» venting radon gas from beneath the building slab (active sub-slab
depressurization - ASD)
» pressurizing and ventilating a school building with an HV AC system (HVAC
pressurization/ventilation)
ASD has been successfully used in homes and school buildings. It is a
particularly effective strategy when initial radon levels are above 20 pCi/L. HVAC
pressurization and ventilation has also been used successfully to reduce radon levels to
below EPA's action level guideline of 4 pCi/L. Because of local building code
requirements, occupancy patterns, school building construction/operation, and initial
radon levels, the use of an HVAC mitigation strategy may be more appropriate than
ASD.
Contractors or school maintenance personnel who have demonstrated
proficiency in radon mitigation through EPA's Radon Contractor Proficiency (RCP)
Program should develop the mitigation strategy for a school. School officials may call
their State Radon Contact or EPA Regional Office for information on State-
Certified and/or RCP-listed contractors (See Appendices A and B). In selecting a
contractor, ask if they have experience mitigating school buildings. It may also be
advantageous to consult an HVAC specialist particularly if an HVAC mitigation strategy
is chosen. More comprehensive information on radon mitigation in schools is available
in Reducing Radon in Schools: A Team Approach (402-R-94-008).
Indoor Air Quality
During EPA's investigations of school mitigation strategies, many schools were
found to have problems with the quality of their indoor air resulting from the lack of
ventilation (the introduction of outside air into the building). In general, for many of
these schools, the ventilation capabilities of their HVAC system(s) were in
Page 18
-------
disrepair or blocked to reduce heating and/or cooling costs. When considering the
indoor air quality of high occupancy buildings like schools, proper ventilation is a
significant part of an overall approach to its improvement.
Active Sub-slab Depressurization
ASD creates a lower air pressure beneath the slab to reverse the flow of air
through the building foundation thus preventing radon entry. This is accomplished by
installing a series of pipes that penetrate the slab or foundation walls. A high suction
fan is attached to these pipes to draw and vent the soil gas (containing radon) from
beneath the building foundation before the gas has a chance to enter into the building.
When radon levels are greater than 10 pCi/L, ASD will probably be needed to lower
levels below EPA's action level of 4 pCi/L. Although ASD is an effective strategy for
controlling radon entry into buildings, it has no other demonstrable effect on the overall
quality of indoor air within a school building other than its effects on radon levels.
The installation of an ASD system should be accompanied by the sealing of
radon entry routes. Sealing will increase the effectiveness of the system and reduce the
energy costs associated with operation of an ASD system. EPA does not recommend
the use of sealing alone to reduce radon levels. EPA studies indicate that sealing will
not lower radon levels consistently.
HVAC Pressurization/Ventilation
The HVAC system(s) in school buildings can directly influence radon entry by
altering air pressure differences between the radon laden soil and the building interior.
Depending on its type and operation, a school's HVAC system may produce positive or
negative air pressure conditions within the building. Positive pressure within the
building can prevent radon from entering a building while negative pressure can permit
or, in some cases enhance, radon entry into the building.
The pressurization of a school building is accomplished when sufficient quantities
of outdoor air are introduced into the building producing a positive air pressure within
the building. Pressurization may require additional heating, cooling, and/or
dehumidification that may exceed the capacity of the existing HVAC equipment. In
addition, routine operation and maintenance will be necessary for this type of mitigation
strategy to consistently reduce radon levels.
Restoring the ventilation capacity of an existing HVAC system to meet its original
design specifications will, in some cases, achieve the appropriate level of building
pressurization. If possible, ventilation rates should be increased to meet current
ventilation standards. Proper ventilation through the introduction of
Page 19
-------
outdoor air can reduce radon levels by diluting the radon that has entered the building.
Some older schools may not have a mechanical ventilation system (HVAC). For these
schools, consideration should be given to the installation of a ventilation system when
addressing radon problems especially since such a system may contribute to an
improvement in the overall indoor air quality of the school.
Because schools vary in their design, construction, and operation, there is no
standard HVAC pressurization and ventilation strategy for all schools. As a result, an
HVAC engineer may need to be consulted when considering HVAC pressurization and
ventilation as a mitigation strategy.
SECTION IV: FREQUENTLY-ASKED QUESTIONS
A. RADON AND RADIATION:
Q: Does radon cause headaches, eye irritation, or sick-building syndrome?
A: No.
Q: Do children have a greater risk than adults for certain types of cancer
caused by radon exposure?
A: Children have been reported to have greater risk than adults of certain types
of cancer from radiation, but there are no conclusive data on whether children
are at greater risk than adults from radon.
Q: What is a picocurie of radiation and why are radon levels reported in
units of picoCuries per liter?
A: All radioactive substances are unstable and undergo radioactive decay. The
amount of radioactivity can be assessed by the number of particles which
decay each minute. A picocurie (pCi/L) of radiation is equal to 2.2
radioactive decays per minute. A measurement result of 1 pCi/L of radon gas
means that in each liter of air there is enough radon to produce 2.2
radioactive decays each minute.
Page 20
-------
Q: What is a "Working Level"?
A: The working level (WL) is a unit used to measure radon decay products. The
concentration of radon decay products suspended in the air can be measured
and expressed in terms of working levels. Working levels, in turn, can be
converted to the concentration of radon gas in pCi/L. The measurement of
radon decay products is most frequently performed with continuous working
level monitors (see Appendix D).
Q: Is radon in water a problem in schools? If so, how do we test for it?
A: The primary entry route of radon into schools is through the soil. However,
radon can also enter through the water supply. It can then be released into
the air while using water. While radon in water is not a problem for most
public water supplies, it has been found in well water. Research suggests
that swallowing water with high radon levels may also pose risks although
these risks are believed to be much lower - in most cases - than those from
breathing air containing radon. EPA has proposed regulations which would
require the testing of public water supplies for radon and other radionuclides.
These regulations also include requirements to reduce elevated levels of
radon in the water supply. These requirements are scheduled to become final
in October 1993.
If your school is serviced by a public water supply, the water will be tested
for elevated radon levels. If an elevated radon concentration is detected, it
will be reduced under the above requirements. If your school is on a well
system and you have found elevated levels of radon in the indoor air, you
should have the water tested for radon. For more information, call EPA's
Drinking Water Hotline (1-800-426-4791) or your State Radon Contact.
Q: Is there any hazard involved in handling radon measurement devices?
A: No.
Q: How does background gamma radiation affect measurements?
A: Of the devices commonly used to make initial measurements in schools, only
electret-ion chambers (EICs) are sensitive to and require correction for
gamma radiation. Gamma correction is a simple calculation made by the
service analyzing the devices. If a gamma radiation measurement is not
made, a background value is assumed.
Page 21
-------
Q: Are building materials likely to contain or emit radon?
A: Radon emission from soil gas and its subsequent entry through the building
foundation is the major source of radon contamination for schools. However,
phosphogypsum wall board has been identified as a potential source of radon
in building structures. The presence of phosphogypsum wall board in
American buildings is very rare. Studies show that when phosphogypsum is
present its contribution to the overall indoor radon concentration is quite
small. EPA has not identified the presence of radon emanations from wall
board in measurements conducted during field studies. In very rare cases,
cinder blocks or concrete may contain enough radium to emit radon.
However, the concentrations are likely to be insignificant.
B. PLANNING FOR TESTING:
Q: In Radon Measurements in Schools - An Interim Report, EPA
recommended that 2-day tests be conducted over a weekend with
HVAC operating continuously (i.e., at maximum setting). Are these test
results still valid given the changes in the school measurement
guidance?
A: Yes. EPA studies indicate that these two testing protocols generally yield
similar results when conducted during the coldest months of the year.
Therefore, schools which have tested according to the interim guidance do
not need to retest using the revised guidance. EPA's revised
recommendation to test on weekdays with normal HVAC operation does not
require school personnel to deviate from the usual schedule of adjustments
to HVAC controls and is designed to reflect, as much as possible, normal
weekday conditions.
Q: Should testing be delayed if a school is planning major renovations to
the building structure or to the HVAC system?
A: Initial and follow-up tests should be conducted prior to major HVAC or
building structure renovations. If the test results indicate a radon problem,
radon-resistant techniques can be inexpensively included as part of the
renovation. Because major renovations can change the level of radon in any
school, school officials should test again after the completion of the
renovation to determine if the radon-resistant techniques are effective.
Page 22
-------
Q: EPA does not recommend testing the upper floors of a school. Does
this mean that upper floors never have elevated levels?
A: Upper floors may have elevated radon levels. However, EPA studies indicate
that a radon level for an upper floor room is not likely to exceed levels found
on the first floor. Therefore, if all measurements in ground-contact rooms are
below the action level, radon concentrations on upper floors are likely also to
be below 4 pCi/L. Furthermore, mitigation of school rooms on the ground
floor, if necessary, will also serve to reduce radon levels on upper floors.
Q: In schools with a basement level (below ground), the first floor is often
built at grade level and, therefore, is in contact with the ground only
along its outside edge. Should this floor be tested?
A: Although such a floor may have limited contact with the ground, the outside
rooms may have openings permitting radon entry and should be tested if they
are frequently occupied. If any of the rooms in the basement are frequently
occupied or may be in the future (for example, if extra classroom space is
anticipated), these basement rooms should also be tested. In addition,
schools with crawl spaces between the ground and first floor should test all
frequently-occupied first-floor rooms.
Q: Some schools and homes near us have reported finding no elevated
radon levels. Do we still need to test?
A: Yes. Since radon levels in buildings vary with local geology, building
structure, and HVAC system, schools in close proximity can exhibit
dramatically different radon levels. The only way to know if the rooms in your
school have elevated radon levels is to conduct radon testing in your school.
Q: What are the costs involved in testing for radon in schools?
A: The costs of testing are primarily dependent on the number of rooms to be
tested, the type of measurement device used, and whether school personnel
Page 23
-------
or a measurement company conduct the testing. As in the procurement of
any equipment or services, it is best to get several estimates (see Appendix
C).
C. CONDUCTING INITIAL MEASUREMENTS:
Q: If a room's short-term, initial test result is very high (for example, near
100 pCi/L), should remedial action be delayed to allow time for a follow-
up measurement?
A: Schools should conduct a follow-up measurement before deciding to
take remedial action. EPA's studies of radon measurements show that the
results from short-term tests become more accurate as radon levels rise
above 4 pCi/L. Therefore, under these circumstances, a school should
consider doing a follow-up short-term test of 2 to 5-days to quickly confirm a
high radon level and to eliminate the possibility of laboratory error. Consult
your State Radon Contact or EPA Regional Office if you discover radon
levels near or greater than 100 pCi/L in your schools (see Appendices A or
B). It may be appropriate to relocate staff and students until the radon level
is reduced.
Q: Should initial or follow-up measurements be conducted only during the
hours when a school is occupied?
A: No. EPA recommends that both initial and follow-up measurements be
conducted for a minimum of 48 continuous hours. This will measure the
effects of daily fluctuations in radon levels in a room and include periods
when radon levels may be at their highest. This provides a more conservative
measure (i.e., more protective) of the radon levels. If elevated radon is found
in a room, the diagnostic phase of mitigation can provide a more definitive
picture of occupied hour levels. This will be part of the information used to
decide how best to reduce radon levels.
D. TAMPERING/DETECTOR PLACEMENT:
Q: Should a room be retested if there is evidence of detector tampering?
A: Another test should be conducted under conditions which insure that
tampering has not affected the measurement results.
Page 24
-------
Q: How do you place radon detectors in large, open areas such as
cafeterias, gymnasiums, or auditoriums?
A: Since flat surfaces elevated from the floor are rare in gymnasiums and
auditoriums, detectors may be hung from walls in these rooms. However,
refer to the manufacturer's instructions for any restrictions on the deployment
of their device. Hanging radon detectors from walls should only be done when
absolutely necessary.
Q: How should we test partitioned classrooms?
A: Classrooms with moveable partitions should be individually tested if the
partitions extend from the floor to ceiling.
E. WEATHER CONDITIONS:
Q: What should be done if unusual weather conditions (e.g., heavy rain,
snow or wind) arise just before a planned 2 to 5-day winter testing
period?
A: EPA recommends that schools avoid testing under these conditions.
Therefore, testing should be postponed.
F. CONDUCTING FOLLOW-UP MEASUREMENTS:
Q: Why does EPA suggest a long-term, follow-up measurement of 9
months rather than a full year?
A: Schools generally conduct classes over a nine-month school year which
excludes summer months. In such a case, the summer months should be
excluded from the measurement period. If your facilities are used continually
throughout the calendar year, and you plan to do a long-term test as a follow-
up measurement, a 12-month test may be more appropriate.
Q: Is a long-term follow-up measurement of any duration greater than
three months recommended?
Page 25
-------
A: EPA uses "long-term" to refer to any measurement over 90 days in
duration. The longer the follow-up test, the better the picture of the average
radon concentration for the school year. If circumstances prohibit testing over
the full school year, consider testing for a measurement period of 6, 7, or 8
months if possible. If the initial test result was about 10 pCi/L or higher, a
short-term follow-up test is more appropriate.
Q: Is it acceptable to use short-term follow-up tests for all rooms even
though EPA's recommendation is to use a long-term follow-up test
when the initial measurement for a room is slightly elevated above 4
pCi/L and to use a short-term follow-up test if the initial test is much
higher (e.g., about 10 pCi/L or greater)?
A: Yes, it is acceptable. EPA recognizes that there can be a range of initial test
results for rooms in a school and this approach may simplify follow-up testing.
Both short-term and long-term radon tests can be used for making mitigation
decisions.
Q: Should quality assurance measurements be made during the follow-up
testing phase?
A: Yes. However, in most schools, there will be fewer follow-up measurements
than during the initial measurement phase since only rooms with elevated
initial measurement results receive follow-up tests. Even if only a few follow-
up measurements are needed, a minimum of one duplicate and one blank
should still be part of a testing plan.
Q: Is the use of continuous monitors ever appropriate for follow-up
testing?
A: Continuous monitors, as well as any other radon devices, may be used
for follow-up testing as long as they are used to measure a period of no fewer
than 48 continuous hours - EPA's minimum acceptable duration for initial and
follow-up measurements. Continuous monitors may be used in accordance
with EPA's measurement protocols for periods of time less than 48 hours only
as part of the diagnostic process.
Page 26
-------
G. QUALITY ASSURANCE:
Q: When two devices (duplicates) are placed in a room during initial
testing for quality assurance purposes, which measurement result is
taken as the test result for that room?
A: The arithmetic average serves as the initial measurement result for that room.
Q: If a device appears to have been damaged or opened before
deployment, may it be used to measure a room's radon concentration?
A: No. Any device which is damaged or opened before deployment cannot be
expected to yield a measurement result of acceptable quality and should not
be deployed.
Q: What should be done if a device is picked up late or found after the
other devices have been shipped for analysis?
A: Devices should be shipped to the analyzing laboratory as soon as possible,
preferably within one or two days after testing ends. Devices that are not
returned quickly may produce invalid results. If a device is picked up or
discovered after two days, record the serial number of the device, record the
actual retrieval time, and call the analytical laboratory or testing service for
advice.
Page 27
-------
APPENDIX A
STATE/INDIAN NATION RADON CONTACTS
ALABAMA
ALASKA
ARIZONA
ARKANSAS
CALIFORNIA
COLORADO
CONNECTICUT
DELAWARE
D.C.
FLORIDA
GEORGIA
HAWAII
IDAHO
ILLINOIS
INDIANA
IOWA
KANSAS
KENTUCKY
LOUISIANA
MAINE
MARYLAND
MASSACHUSETTS
MICHIGAN
MINNESOTA
MISSISSIPPI
MISSOURI
MONTANA
NEBRASKA
NEVADA
NEW HAMPSHIRE
NEW JERSEY
NEW MEXICO
NEW YORK
NORTH CAROLINA
NORTH DAKOTA
OHIO
OKLAHOMA
OREGON
PENNSYLVANIA
RHODE ISLAND
SOUTH CAROLINA
SOUTH DAKOTA
TENNESSEE
TEXAS
UTAH
800-582-1866
800-478-8324
602-255-4845
501-661-2301
800-745-7236
800-846-3986
203-566-3122
800-554-4636
202-727-5728
800-543-8279
800-745-0037
808-586-4700
800-445-8647
800-325-1245
800-272-9723
800-383-5992
913-296-6183
502-564-3700
800-256-2494
800-232-0842
800-872-3666
413-586-7525
800-723-6642
800-798-9050
800-626-7739
800-669-7236
406-444-3671
800-334-9491
702-687-5394
800-852-3345 X4674
800-648-0394
505-827-4300
800-458-1158
919-571-4141
701-221-5188
800-523-4439
405-271-1902
503-731-4014
800-237-2366
401-277-2438
800-768-0362
800-438-3367
800-232-1139
512-834-6688
800-536-4250
VERMONT
VIRGINIA
WEST VIRGINIA
WISCONSIN
WYOMING
PUERTO RICO
All Indian Pueblo Council
Cherokee Nation
Chickasaw Nation
Hopi Tribe
Inner Tribal Council
Jicarilla Apache Tribe
Navajo Nation
Oneida Indian Nation
Seneca Nation
St. Regis Mohawk Tribe
800-640-0601
800-468-0138
800-922-1255
800-267-4795
800-458-5847
809-767-3563
505-881-2254
918-458-5496
405-436-2603
602-734-2441
602-248-0071
505-759-3242
602-871-7754
315-361-6300
716-532-0024
518-358-3141
For Indian Nations in the States of MN, Wl,
Ml, IL, IN, and OH 312-886-6063
Page 28
-------
APPENDIX B
EPA REGIONAL OFFICES AND RADON TRAINING CENTERS
Map of EPA Regions
Each of the 50 United States, as well as the District of Columbia, the Virgin
Islands, and Puerto Rico, has been assigned to one of 10 Federal Regions. This map
shows the Regional assignments for the 50 States. Puerto Rico and the Virgin Islands
are assigned to Region 2. The District of Columbia is in Region 3. Identify your Region
on the map below and refer to next page for a telephone number and address.
Page 29
-------
EPA REGIONAL RADIATION (RADON) PROGRAM MANAGERS
Region 1
Radiation Program Manager
U.S. Environmental Protection Agency
John F. Kennedy Federal Building
Boston, MA 02203-2211
(617)565-4502
Region 2
Chief, Radiation Branch (2AWM-RAD)
U.S. Environmental Protection Agency
Federal Plaza, Room 1005A
New York, NY 10278
(212)264-4110
Region 3
Radiation Program Manager
Radiation Programs Section (3AT12)
U.S. Environmental Protection Agency
841 Chestnut Street
Philadelphia, PA 19107
(215)597-8326
Region 4
Radiation Program Manager
U.S. Environmental Protection Agency
345Courtland Street, N.E.
Atlanta, GA 30365
(404) 347-3907
Region 5
Radiation Program Manager
(AT-18J)
U.S. Environmental Protection Agency
77 West Jackson Boulevard (A T -082)
Chicago, IL 60604-3507
(312)886-6175
Region 6
Radiation Program Manager
U.S. Environmental Protection Agency
1445 Ross Avenue (6T -AG)
Dallas, TX 75202-2733
(214)665-7223
Region 7
Radiation Program Manager
U.S. Environmental Protection Agency
726 Minnesota Avenue
Kansas City, KS66101
(913)551-7020
Region 8
Radiation Program Manager
(8ARTRP)
U.S. Environmental Protection Agency
999 18th Street, Suite 500
Denver, CO 80202-2405
(303)293-1709
Region 9
Radiation Program Manager
(A-1-1)
U.S. Environmental Protection Agency
75 Hawthorne Street
San Francisco, CA 94105
(415)744-1048
Region 10
Radiation Program Manager
(AT-082)
U.S. Environmental Protection Agency
1200 Sixth Avenue
Seattle, WA 98101
(206) 553-7660
Page 30
-------
RADON TRAINING CENTERS
Eastern Regional Radon Training
Center (EERTC)
Rutgers University
Livingston Campus, Bldg. 4087
New Brunswick, NJ 08903
(908) 932-2582
FAX 908-932-4918
Western Regional Radon Training
Center (WRRTC)
Department of Industrial Sciences
IS Bldg. Room 200-B
Colorado State University
Fort Collins, CO 80523
(800) 462-7459 or (303) 491-7742
FAX 303-491-7801
Southern Regional Training Center
(SRRTC)
Auburn University
107 Ramsay Hall
Auburn University, AL 36849-5332
(800) 626-2703 or (205) 844-5719
FAX 205-844-5715
Midwest Universities Radon
Consortium (MURC)
University of Minnesota
1985 Buford Avenue (240)
St. Paul, MN 55108-6136
(612)624-8747
FAX 612-624-3113
Page 31
-------
APPENDIX C
USING A MEASUREMENT SERVICE
Although school personnel may design and implement a radon testing program,
some schools may prefer to contract with an organization that provides radon
measurement services. For example, in addition to supplying measurement devices
and analytical services, a qualified measurement contractor could supervise the entire
measurement procedure including the selection of sampling locations, the placement of
measurement devices, and the implementation of a quality assurance program.
Alternatively, a school may choose to place and collect measurement devices while the
contractor selects the sampling locations and implements the quality assurance plan.
Regardless of the degree of contractor involvement, the following guidelines may be
useful when employing a radon measurement contractor:
Selecting a Measurement Service
» Invite the measurement service to walk through your school building before
formulating their estimate.
» Select a measurement service that is listed with your State Certification
Program or with EPA's Radon Measurement Proficiency (RMP) Program.
Verify RMP-listing by requesting a copy of the current listing letter or an I.D.
card.
» Request references and check contractor's service history with your State
Radon Contact, Better Business Bureau, and State Department of Consumer
Protection.
» Obtain several written proposals with bids for radon measurement services.
» Request written estimates which give the total number of devices needed in
addition to their total costs. This will enable you to determine if the proposed
quantity will be sufficient to measure all sampling locations and to conduct
quality assurance measurements.
Evaluating Proposals from RMP-listed Services
» Review the quality assurance plan (QAP) of the measurement service. For
companies providing measurement and/or analytical services (primary
services), QAPs should contain procedures for the following:
calibration of instruments;
Page 32
-------
chain of custody for specific devices;
assessing contamination from background radiation; and
assessing accuracy and precision using spikes, blanks, and duplicates.
For companies providing measurement services only (secondary services), QAPs
should contain:
testing procedures consistent with this document;
procedures for device deployment and retrieval consistent with
manufacturer's instructions;
quality assurance procedures consistent with this document; and -use of
State or RMP-certified analysis lab.
Developing a Contract
After selecting a contractor, request that they prepare a contract detailing the
terms described in the proposal. Carefully read the contract before signing. Consider
including the following in the contract:
» A limit on the time required to report the measurement results (EPA's RMP
program requires reporting of results within 30 calendar days after completion
of testing).
» The contract should include a description of exactly what work will be done
prior to and during the testing period, the time required to complete the work,
and the total cost of the job including all applicable taxes, permit fees, down
payment (if any), and date of payment.
» A guarantee that the measurements will meet the standards required by
EPA's RMP Program and the quality assurance guidelines outlined in this
document. The guarantee should include provisions in the event that
measurements do not meet these standards (e.g., to reconduct testing or
portions thereof at no cost to the school).
» A statement that liability insurance and applicable worker's compensation
coverage is carried by the organization in the event of injury to persons or
damage to property during the measurement process.
Page 33
-------
APPENDIX D
MEASUREMENT DEVICES
This appendix contains brief introductory descriptions of the various
measurement devices mentioned in this guidance document. Further information on
each device, including EPA's approved protocols for their use and specific quality
assurance requirements, may be found in EPA's document entitled Indoor Radon and
Radon Decay Product Measurement Protocols (EPA 402-R-92-004). All devices used
for measuring radon in schools should meet EPA Radon Measurement Proficiency
(RMP) Program requirements and should be used in strict accordance with
manufacturer's instructions.
Passive Device: A radon measurement device which requires no electrical power
to perform its function. Passive devices are exposed to indoor air by being "uncapped"
or similarly activated, then left in place for a length of time known as the measurement
period. All of the devices described below are passive devices, except continuous
monitors which are active devices.
Active Device: A measurement device which requires an electrical power source
and which is capable of charting radon gas or radon decay product concentration
fluctuations throughout the course of a given measurement period (usually by producing
integrated periodic measurements over a period of two or more days).
Activated Charcoal Adsorption Devices (AC)
ACs are passive devices. The charcoal within these devices has been treated to
increase its ability to adsorb gases. The passive nature of the activated charcoal allows
continual adsorption and desorption of radon. During the entire measurement period
(typically two to seven days), the adsorbed radon undergoes radioactive decay. This
technique does not adsorb radon uniformly during the exposure period; as a result,
these devices are not true integrating devices. Moreover, ACs should be promptly
returned to the laboratory after the exposure period (by mail service that guarantees
delivery within two to three days at maximum).
As with all devices that store radon, the average concentration calculated is
subject to error if the radon concentration in a room varies substantially during the
measurement period. Therefore, the recommendations discussed in SECTION II (D)
should be followed when using AC devices.
Variations of AC are presently available. A device used commonly contains
charcoal packaged inside an air-permeable bag. Radon is able to diffuse into this
Page 34
-------
bag where it can be adsorbed onto the charcoal. Another device used commonly
consists of a circular, 6 to 10-centimeter (cm) container that is approximately 2.5 cm
deep and filled with 25 to 100 grams of activated charcoal. One side of the container is
fitted with a screen that keeps the charcoal in but allows air to diffuse in the charcoal.
For some of these devices, the charcoal container has a diffusion barrier over the
opening. For longer exposures, this barrier improves the uniformity of response to
variations of radon concentration with time.
Charcoal Liquid Scintillation (CLS) Devices
Charcoal liquid scintillation (CLS) devices are passive detectors which function
on the same principle as charcoal canisters. CLS devices retain radon on 1 to 3 grams
of charcoal in a glass vial approximately 1 inch in diameter and 2 % inches in height.
They are called "liquid scintillation" devices because they are analyzed by transferring
the charcoal with radon to a fluid and placed in a scintillation counter where the radon
level is determined from the rate of scintillations (flashes of light) that result from the
interaction of the radon decay products with the scintillation fluid. Like AC devices, CLS
devices are not true integrating devices and sometimes contain a diffusion barrier. In
addition, CLS devices must be resealed and sent to the laboratory for analysis promptly
after the exposure period (by mail service that guarantees delivery within two to three
days).
Electret-lon Chambers (EICs)
Electret-ion chamber detectors (EICs) are passive devices which function as true
integrating detectors measuring the average radon gas concentration during the
measurement period. EICs take advantage of the fact that the radiation emitted from
the decay of radon and its decay products imparts an electrical charge on the airborne
particles that are released during the decay of these particles. These charged particles
(ions) are attracted to an electret (electrostatically charged disk of Teflon®) in the EIC
housing which reacts to their presence by losing some of its voltage. The amount of
voltage reduction is directly related to the average concentration of radon within the
chamber during the exposure period.
EICs may be designed to measure for short periods of time (e.g., 2 to 5 days) or
for long periods of time (e.g., 9 months). The type of the electret (i.e., short or long-
term) and chamber volume determine the usable measurement period. The electret is
removed from the canister and its voltage measured with a special surface voltmeter
both before and after the exposure period. The difference between these two voltage
readings is used to calculate the average radon concentration. The devices may be sent
to a laboratory for measurement, or a school can purchase special equipment (i.e.,
voltmeter) that can measure the radon concentration soon after its detection. Schools
that purchase voltmeters for reading electrets should enroll in the Radon Measurement
Proficiency Program or have special training for operating these instruments.
Page 35
-------
Alpha Track Detectors (ATDs)
An alpha track detector (AID) is a passive device consisting of a small piece of
plastic or film (the sensor) enclosed in a housing with a filter-covered opening. Radon
diffuses through the filter into the housing where it undergoes radioactive decay. This
decay produces particles of alpha radiation which strike the sensor and generate
submicroscopic damage called alpha tracks. Alpha tracks on the sensor can be
counted under a microscope in a laboratory. The number of tracks counted determines
the average radon level over the exposure period. ATDs have no bias toward a specific
part of the exposure period; therefore, they function as true integrating devices. In
addition, they are most commonly used for measurements of three to nine months in
duration.
Continuous Radon Monitors and Working Level Monitors
Continuous monitors are the only active devices mentioned in this list. They
utilize various types of sensors. Some collect air for analysis with a small pump while
others allow air to diffuse into a sensor chamber. All have electrical circuitry capable of
reporting (and usually recording) integrated radon concentrations for periodic intervals
(e.g., every hour or every five minutes). Continuous radon monitors measure radon
gas. Continuous working level monitors, on the other hand, measure radon decay
product concentrations. Schools that purchase continuous monitors should participate
in the Radon Measurement Proficiency Program or have special training to operate
these instruments.
Page 36
-------
APPENDIX E
QUALITY ASSURANCE PROCEDURE
After receiving the results from the analysis of your initial or follow-up tests, take
the following steps to evaluate whether or not these measurements were conducted
with adequate quality. To perform these steps, you will need your completed Device
Placement Log (See Appendix F).
Analysis of Duplicates
The following steps are for activated charcoal adsorption devices, electret-ion
chamber devices, charcoal liquid scintillation devices, and alpha track devices. See
SECTION II (F) for a brief discussion on the use of duplicates to evaluate the precision
of your measurements.
_ 1 Identify your duplicate measurements on the Device Placement Log. Each row
containing a "D" in the "Room #" column represents the second duplicate pair
(hereafter, D2). The device listed in the row immediately above the "D" listing is
the first duplicate pair (hereafter, DI).
_ 2 Transfer the results for each duplicate pair to the Duplicate Log (see sample at
the end of this appendix). Place the first duplicate in the " DI" column. Place
the second duplicate in the " D2" column. Repeat this step for all duplicate
pairs.
_ 3 Calculate the average (mean) for each duplicate pair using the following
equation:
average (M) =
4 Record the average of the pair in the "M" column of the Duplicate Log.
5 Place an "X" in the "M > 4" column for duplicate pairs that have an average of 4
or greater. The following steps should only be conducted for those duplicate
measurements where the average of the two measurements is greater than or
equal to 4 pCi/L. If the average for every duplicate pair is below 4, see the
footnote at the end of this appendix.
6 Count the total number(N) of "X's" in the "M > 4" column. Write this total in the
space indicated at the bottom of the "M > 4"column.
Page 37
-------
7 Calculate the relative percent difference (RPD) for each duplicate pair that has
an "X" in the "M > 4" Column using one of the two formulas below:
a) If DI is greater than D2, then the
relative percent difference (RPD) = D^-D? x 100 = %
M
b) If D2 is greater than DI, then the
(RPD) = Dg-Dj x 100 = %
M
_ 8 Record the relative percent difference in the "RPD" column.
_ 9 Determine the total relative percent difference (TRPD) by adding together all
the "RPD" values in the "RPD" column. Record the TRPD in the space indicated
at the bottom of the "RPD" column.
_10 Determine the average relative percent difference (ARPD) for all duplicate
pairs by dividing the TRPD (from step 9) by the N (from step 6). Record this
result here ARPD = (see the example calculation using data from the
sample duplicate log on the next page).
(ARPD) = TRPD = 49.0 = 12.3%
N 4
.11 If the ARPD for all duplicate pairs exceeds 25%, then the quality of the
measurements is questionable. Contact the laboratory analyzing the devices
or the measurement service for assistance in determining if there is a problem
and if any retesting is necessary.
Analysis of Blanks
The following two steps are for all passive measurement devices. See SECTION
II (F) for brief discussion on the use of blanks to evaluate the accuracy of your
measurements.
1 Identify your blank measurements on the Device Placement Log. Note each row
containing a "B" on the Room #/Name column represents a blank.
Page 38
-------
2 If any of the blank measurements is equal to or greater than 1.0 pCi/L, contact
the analyzing laboratory or measurement service and request an explanation for
the inaccuracy in the blank result.
DUPLICATE LOG
SAMPLE
0,
M
N =
RfO
TRPD =
D,
1.4
0,8
3.9
4.6
4.1
0.3
0.8
6.4
4.2
1.8
3.0
4.5
0.5
D,
1.2
1,1
3,5
5.1
3,8
2.0
0.5
7.2
2.5
2.4
2.3
3.7
0.6
M
1.3
1.0
3.7
4.9
4.0
1.2
0,7
6.8
3.4
2.1
2,7
4,1
0.6
Ma4*
X
X
X
X
N= 4
RPD
10.2
7.5
11.8
19.5
TRPD = 49,0
* Duplicate pairs with an average less than 4 are not considered because of the
inherent limitations of measurement devices at radon concentrations below 4 pCi/L of
air. If the average of each duplicate pair is below 4, assume that the precision of the
duplicate measurements is acceptable given the measurement device's limitations and
proceed to the Analysis of Blanks section.
Page 39
-------
APPENDIX F
PROCEDURAL CHECKLIST FOR RADON TESTING
The following checklist presents a step-by-step guide for conducting a radon
testing program for a school building. The issues discussed in SECTION II of this
document have been incorporated into this checklist in chronological order. The reader
should be familiar with the issues discussed in this section before using this checklist.
In addition, the reader should review and understand each section of this checklist
before proceeding through the steps.
A Device Placement Log has been included at the end of this appendix.
Several copies of this log sheet should be made before initiating a testing program. You
will use these log sheets to record relevant information as you proceed through these
steps.
Planning a Testing Program
1 If possible, plan to test in the early part of the cold weather testing season in
your area (e.g. October to March) so that follow-up measurements (if needed)
may be conducted under similar conditions. If using 90-day measurements, start
early in the heating season.
Early in the planning phase, count the rooms to be tested (e.g., all frequently-
occupied, ground-contact rooms). Add an additional 15 percent of this total to
account for the duplicates (10%) and blanks (5%) but do not exceed 50
duplicates and 25 blanks. This will give you the number of detectors that you
will need to conduct a testing program.
3 Your selected measurement device should be listed with EPA's Radon
Measurement Proficiency (RMP) Program. To insure that a device is RMP-
listed check its packaging for the phrase "meets EPA RMP-requirements" or
"meets EPA proficiency requirements". If these phrases are not on the
packaging call your State Radon Contact (see Appendix A).
4 Use a floor plan to identify the rooms where initial testing will be conducted.
Simple diagrams like the Sample Floor Plan provided at the end of this
appendix are adequate for this purpose. Make a check in each room to be
tested. If you do not have standard room numbers for all of these rooms, assign
numbers to them.
Page 40
-------
These numbers will be used to match devices with the rooms where they were
deployed. Record these numbers on your floor plan.
5 A few days before the beginning of the test period, go to each room and choose
a location for the detectors. Note these locations (e.g., south wall filing cabinet)
on the Device Placement Log (see example at the end of this appendix). This
will prevent excessive delays during device deployment. Follow the guidelines
for detector placement in SECTION II (C) of this document.
6 The walk-through described in step 5 is also the best time to select rooms in
which duplicate devices will be deployed. Mark these rooms with a large "D" on
your floor plan. Approximately 10% of the rooms tested should contain
duplicates placed side-by-side.
7 Randomly mark with a "B" on your floor plan as many rooms as the number of
blanks you will need. This will enable you to intersperse the duplicates and
blanks on the Device Placement Log (hereafter, log sheet) that you send to the
analyzing laboratory so that the lab will not be able to tell which of the recorded
measurements are duplicates and blanks. Make copies of your completed floor
plan and log sheets and keep it in a file that documents your testing program.
8 When the measurement devices arrive from shipment, count them to make sure
that there will be enough. Carefully read all the information provided by the
manufacturer and/or supplier regarding detector handling, deployment
procedures, shipping, detector shelf life, etc. It is very important that you
understand and follow all instructions provided with your detector. Should
you have any questions, call the manufacturer, State Radon Contact, or EPA
Regional Office for assistance.
Deploying the Measurement Devices
9 Notify students and staff about testing and provide educational materials on
radon before the testing period begins. This will help to prevent inadvertent
tampering, damage and/or loss of detectors. Emphasize to students and
teachers that a reliable test result depends on their cooperation because any
disturbance with the test device or interference with the closed conditions,
especially during short-term test, will invalidate the test results.
Page 41
-------
_10 Other information to be recorded for each device includes: room number and/or
name, deployment location, device number (the manufacturer's serial number),
date and time of deployment ("start date and time"), date and time of pickup
("stop date and time"), and comments (for noting any special circumstances,
such as evidence of tampering, late pickup, etc.). The Device Placement Log
(hereafter, log sheet) may be used to record this information. The first four
columns of the form may be filled out a day or two early in order to save time
during deployment.
_11 Remember to intersperse locations for duplicates and blanks on the log sheet
(see steps 13 and 15 below). The Sample Floor Plan and Sample Device
Placement Log at the end of this appendix provide an example of how rooms
on the floor plan are recorded on the log sheet.
_12 All radon detectors should be deployed in a school on the same day. On the day
of deployment, place detectors in the preselected locations in each room and
carefully note the time of deployment (for example, "5:42 P.M."). Since the
recorded time of deployment should not be off by more than about ten minutes,
make certain to record it immediately after opening and deploying the device.
This is particularly important for 2 to 5-day measurements.
_13 Duplicate devices should be placed in all rooms marked earlier with a "D" on
your floor plan. Duplicate pairs are placed side-by-side in the same room so
that they will measure the same air. Both devices of a duplicate pair should be
given separate entry lines in the log sheet. Place a "D" in the "Room #/Name"
and "Location" columns for the second device of the pair so that duplicate pairs
will be easy to distinguish from the other measurements on the log sheet.
These columns will later be covered so that the analyzing laboratory will be
unable to distinguish the duplicates from the other measurements.
.14 Record the serial numbers for the two devices of a duplicate pair as you would
for the other measurements but add a few minutes (e.g., 2 to 5) to the
deployment time for the second device of the pair so that the lab will not know
that they were duplicates deployed at the same time and location. See the
completed log sheet at the end of this appendix for an example of how to record
duplicates on a log sheet. Pause for a few minutes before deploying the
detector in the next room to avoid having similar "start times" between the
duplicate and the detector in the next room.
Page 42
-------
.15 Blank devices should not be deployed. Instead, they are kept in safe
storage, unopened, throughout the measurement period. Blanks should be
recorded in the log sheet as separate entries immediately following the listings
for rooms marked earlier on the floor plan with a "B". Carefully record on the log
sheet the serial number of the blank device before setting it aside.
.16 Place a "B" in the "Room #/Name" and "location" columns of the log. Although
the blanks are not actually deployed, it is still important to record deployment
dates and times for these blank devices. Do this by adding a few minutes (e.g.,
2 to 5) to the deployment time that you recorded for the device listed just prior to
the blank's listing. A completed log sheet at the end of this Appendix has an
example on how to record blanks on the log sheet.
17 Depending on the type of radon detector you purchase, there might be a label on
each device for recording the dates and times of deployment and retrieval. If so,
record this information on the labels as well as the Device Placement log. This
redundancy assures that the laboratory will use the correct dates and times in
calculating room radon levels.
Record Keeping During Testing
.18 During testing, particularly if you are conducting 2-day to 5-day tests, note in the
"Comments" column of the log sheet any unusual or extreme weather conditions
(such as snow storms, heavy rain or high winds) that occur just before or during
the measurement period.
Retrieving the Measurement Devices
.19 On the last day of the deployment period, all devices must be retrieved. Make
sure that you have read all manufacturer's instructions about retrieving, closing,
and resealing the detectors since each type of device has its own procedures.
_20 When picking up each device, check its location and serial number with what
was recorded during deployment. Note any discrepancies in the "Comments"
column of the log sheet. If the serial number does not agree with the one listed,
change the number in the log to the "new" one and note the change as a
comment.
Page 43
-------
_21 Record the date and time of retrieval in the log sheet for each device. Do the
same for duplicates and blanks, adding a few minutes (e.g., 2 to 5) to the
retrieval time that you recorded for the device listed just above. It may be
necessary to pause for a few minutes before retrieving the detector in the next
room to avoid time entries too close together. Finally, print your name in the
space provided at the end of the log sheet. The Sample Device Placement Log
at the end of this appendix provides an example of how to record this
information.
Preparing the Devices for Analysis
_22 After retrieving the deployed detectors, blank devices must be prepared and
mixed in with these detectors for shipment. In preparing the blanks, remember
that the laboratory analyzing the devices should not be able to recognize them
as blanks. Therefore, any seals on the blanks must be broken (in some cases,
the device must be opened and immediately reclosed) and resealed in the same
manner as the deployed detectors.
_23 When devices have been retrieved and prepared for shipment, make sure that all
the necessary information for each device has been recorded on the log sheet.
_24 Make a special copy of the log sheet for the analyzing laboratory by
covering the "Room #/Name" and "Location" columns with a blank piece of
paper before copying. Be careful not to cover any of the other columns
particularly the device serial number and the start/stop dates and times. This
special copy of your log sheet keeps the identities of the duplicates and blanks
masked from the lab.
_25 Include this special copy of the log sheet with the shipment of detectors
that were deployed in the school.
Page 44
-------
SAMPLE DEVICE PLACEMENT LOG
Page 1 of 1
SCHOOL: Oldtown High School
Room it 1 Name
100
102
104
106
B
108
110
112
114
116
115
113
D
111
109
107
105
103
101
D
Location
S wall cabinet
bookshelf
file cabinet
file cabinet
B
teacher's desk
on lockers
above shelves
storage cabinet
N wall
bookshelf
shelf (SE side)
D
2nd file cab.
hung from ceil.
on shelf
fire ext. case
desk (W corner)
N wall shelves
D
Serial tt
65093
93277
17349
84758
09543
69299
59021
48770
56673
80173
28556
74305
97033
86848
96026
19485
67809
32289
65617
22021
Start Date
11/1/93
••
••
"
»
••
••
"
-
«
•<
••
••
••
Start Time
7:22 AM
7:26 AM
7:31 AM
7:33 AM
7:35 AM
7:37 AM
7:40 AM
7:45 AM
7:47 AM
7:50 AM
7:52 AM
7:55 AM
7:58 AM
8:02 AM
8:05 AM
8:08 AM
8:12 AM
8:14 AM
8:17 AM
8:20 AM
Stop Date
11/5/93
••
•<
-
••
»
•>
«
••
•<
„
••
»
Stop Time
4:34 PM
4:37 PM
4:42 PM
4:44 PM
4:46 PM
4:49 PM
4:51 PM
4:53 PM
4:56 PM
4:58 PM
5:01 PM
5:03 PM
5:06 PM
5:08 PM
5:12 PM
5:14 PM
5:17 PM
5:19 PM
5:21 PM
5:24 PM
Comments
slight damage
device fell
Result
NAME:
-------
DEVICE PLACEMENT LOG
Page of
SCHOOL:
Room # / Name
Location
Serial ft
Start Date
Start Time
Stop Date
Stop Time
Comments
Result
NAME:
-------
SAMPLE FLOOR PLAN
SCHOOL: Qldtown High School
N
t
102
104
106
B
108
110
112
114
116
Central Hallway
101
D
103
105
107
109
111
113
D
115
------- |