Attach 1e. Bioenvironmental Engineering Guidebook for Radon Management 3rd Edition (1).pdf

AFRL-SA-WP-TR-2021-0003

Bioenvironmental Engineering Guidebook for Radon

Management Capt Keith J. Westpfahl, Capt Stephanie A. Ohms, SSgt Jesse M. Ford, SSgt Michael J. Anderson, and SSgt David M. Flint

Occupational & Environmental Health

Report Date 27 April 2021

Final Report

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Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine Occupational & Env. Health 2510 Fifth St., Bldg. 840 Wright-Patterson AFB, OH 45433-7913

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This report is published in the interest of scientific and technical information exchange and its publication does not constitute the Government’s approval or disapproval of its ideas or findings.

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LANA D. HARVEY, DR-3, USAF

Chief, Consultative Services Division Occupational & Env Health Department

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4. TITLE AND SUBTITLE

Bioenvironmental Engineering Guidebook for Radon Management 3rd Edition

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Capt Keith J. Westpfahl, Capt Stephanie A. Ohms, SSgt Jesse M. Ford, SSgt Michael J. Anderson, and SSgt David M. Flint

5d. PROJECT NUMBER

5e. TASK NUMBER 5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

REPORT NUMBER

AFRL-SA-WP-TR-2021-0003 Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine Occupational & Env. Health 2510 Fifth St., Bldg. 840 Wright-Patterson AFB, OH 45433-7913

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine Occupational & Env. Health 2510 Fifth St., Bldg. 840 Wright-Patterson AFB, OH 45433-7913

AGENCY ACRONYM(S)

USAFSAM/ OE

11. SPONSORING/MONITORING

AGENCY REPORT NUMBER(S)

AFRL-SA-WP-TR-2021-0003

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DISTRIBUTION STATEMENT C. Distribution authorized to U.S. Government agencies and their contractors;

Administrative or Operational Use; April 2021. Other requests for this document shall be referred to USAFSAM/OE, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

13. SUPPLEMENTARY NOTES

This version of the report is the best quality available.

14. ABSTRACT

This guide provides Bioenvironmental Engineering with information about monitoring installations for high indoor radon. It emphasizes the importance of radon sampling and mitigation to protect USAF personnel and dependents work in or residing in Air Force-controlled buildings. It outlines common radon measurement industry practices, EPA guidance, sampling procedures, and post-sampling recommendations.

15. SUBJECT TERMS

Air Force, Radon, Detection, Monitoring, Exposure, Environmental, Health, Radiation, Assessment, Mitigation, RAMP, Sampling, Guide, Technical Guide

16. SECURITY CLASSIFICATION OF: 17. LIMITATION

OF ABSTRACT:

SAR

18. NUMBER OF

PAGES

19a. NAME OF RESPONSIBLE PERSON (Monitor)

a. REPORT Unclassified

b. ABSTRACT Unclassified

c. THIS PAGE Unclassified

USAFSAM/OEC

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N/A Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18

I

Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine

Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine

Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine

Bioenvironmental Engineering Guidebook for Radon Management

DISTRIBUTION STATEMENT C. Distribution authorized to U.S.

Government a gencies and their contractors; Administrative or

Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

3rd Edition

DISTRIBUTION STATEMENT C. Distribution authorized to U.S. Government agencies and their contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

On the previous page: Radon sampling equipment. (Photographed by SSgt David Flint at Wright-Patterson AFB, OH) i contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

TABLE OF CONTENTS

LIST OF FIGURES ................................................................................................................................................ III LIST OF TABLES .................................................................................................................................................. III

1 INTRODUCTION

1.1 CHANGES FROM THE BE’S GUIDEBOOK FOR RADON MANAGEMENT, 2ND EDITION

1.2 WORKING LEVEL MONTHS IN A YEAR (WLM/YR)

1.3 USAFSAM SUPPORT

2 PLANNING A SURVEY

2.1 REASONS FOR SAMPLING

2.2 DETERMINING IF SAMPLING IS REQUIRED

2.2.1 Determine the Risk Category

2.3 SELECTING STRUCTURES TO MONITOR

2.3.1 Determine the Base Size

2.3.2 Develop the Sampling Plan

2.3.3 Develop Sampling-Sites

2.3.4 Selecting Buildings to Monitor in a Sampling-Site

2.4 SELECT ROOMS TO MONITOR

2.4.1 Testable Rooms Criteria

2.4.2 Non-Testable Rooms/Locations

2.4.3 Number of Rooms/Locations to Test

2.5 SHORT-TERM VS LONG-TERM MONITORING

2.6 CLOSED BUILDING CONDITIONS

2.7 NORMAL OCCUPANCY CONDITIONS

2.8 REQUESTING SAMPLING EQUIPMENT FROM USAFSAM

3 PERFORMING A SURVEY

3.1 PLACING DETECTORS IN THE ROOM

3.2 MINIMIZING DETECTOR LOSS

3.3 SAMPLING EQUIPMENT INFORMATION

3.3.1 Voltage Reader Kit

3.3.2 Field Electrets

3.3.3 Chambers

3.3.4 Combining Chambers and Electrets

3.4 INITIAL SURVEY DOCUMENTATION

4 AFTER A SURVEY

4.1 ENDING SURVEY DOCUMENTATION

4.2 CALCULATING RADON CONCENTRATIONS

4.3 TESTING ERRORS AND INVALID RESULTS

4.3.1 Catastrophic Errors

4.3.2 Minor Errors

4.4 RETESTING MISSED ROOMS, MISSING SAMPLERS, AND INVALID RESULTS

4.5 QUALITY ASSURANCE AND QUALITY CONTROL (QA/QC)

4.5.1 Blanks

4.5.2 Duplicates

4.5.3 Field Sample Checks

4.6 DATA ANALYSIS

4.6.1 Validating Results

4.6.2 Confirming Elevated Results

4.6.3 Sequential Measurements Averaging

4.6.4 Analyzing Test Data from Other Sources

4.7 RADON MEASUREMENT REPORTING REQUIREMENTS

4.8 DATA MANAGEMENT

ii contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

4.8.1 Disclosing Results to Stakeholders

4.8.2 Records Management

4.8.3 Risk Assessment Code (RAC) Assignments

4.9 PERIODIC RETESTING

APPENDIX A RADON ASSESSMENT AND CATEGORIZATION METHODOLOGY

APPENDIX B FLOWCHART TO DETERMINE SAMPLING REQUIREMENT FOR UNCATEGORIZED BASES

APPENDIX C FLOWCHART TO DETERMINE SAMPLING REQUIREMENT FOR CATEGORIZED BASES

APPENDIX D LOCAL RADON MAPS

APPENDIX E CONSULTATION GENERAL INFORMATION AND GUIDELINES

APPENDIX F REFERENCES

APPENDIX G ACRONYMS AND ABBREVIATIONS

iii contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

FIGURE 1. ADJACENT ROOMS ON UPPER FLOORS

FIGURE 2. LEADING CAUSES OF SAMPLER LOSS

FIGURE 3. NOTICE TO TENANT

FIGURE 4. VOLTAGE READER

FIGURE 5. ELECTRETS

FIGURE 6. S-CHAMBER (OPEN CHAMBER ON LEFT, CLOSED ON THE RIGHT)

FIGURE 7. L-O CHAMBERS ARE ALWAYS 'ON'

FIGURE 8. L-OO CHAMBER (CLOSED)

FIGURE 9. RADON ASSESSMENT AND CATEGORIZATION METHODOLOGY

FIGURE 10. FLOWCHART TO DETERMINE SAMPLING REQUIREMENT FOR UNCATEGORIZED BASES

FIGURE 11. FLOWCHART TO DETERMINE SAMPLING REQUIREMENT FOR CATEGORIZED BASES

TABLE 1. RECOMMENDED BUILDING OCCUPANCY FACTORS

TABLE 2. COMMON ASSESSMENT TYPES

TABLE 3. RISK CATEGORIES

TABLE 4. DIFFERENCE BETWEEN SHORT-TERM AND LONG-TERM MEASUREMENTS

TABLE 5. EIC CONFIGURATIONS

TABLE 6. CONSTANTS FOR SAMPLING CONFIGURATIONS

TABLE 7. ACCEPTABLE RELATIVE PERCENT DIFFERENCE MEASUREMENTS

TABLE 8. SEQUENTIAL TESTING AVERAGING EXAMPLE

TABLE 9. TWA EXAMPLES

TABLE 10. LOCAL RADON MAPS

LIST OF FIGURES

LIST OF TABLES

contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

This guide is intended to help installation Bioenvironmental Engineering (BE) perform radon sampling to assess risk and to establish if mitigation is required to protect building occupants. At joint-base installations, it may be necessary to adapt the business practices laid out in this guide with similar guidance from other services such as the Navy Radon Assessment And Mitigation Guidebook for Naval Shore Installations or radon reduction programs laid out by the Army.

Section 2 discusses the AF methodology used to plan a radon survey. This includes common reasons for sampling, how to select sample locations on an installation and inside of selected buildings. Section 3 explains how to execute this plan. This includes the procedures BE should follow when sampling equipment is provided, where to place samplers in a room, and technical information about the equipment provided by the United States Air Force School of Aerospace Medicine (USAFSAM). Section 4 describes how to analyze the information collected during the sampling event. This includes step-by-step procedures for manually calculating the voltage lost during the sampling event into picocuries per Liter (pCi/L) activity, then into Working Level Months in a year (WLM/yr) exposure. It goes on to explain how those calculated results are used to determine if radon mitigation is required, how to document these sample results, and what to report to stakeholders.

Appendix A lays out the methodology used to determine a base’s Radon Risk Category and the recommended actions applicable to each category. The decision-tree in Appendix B is useful for uncategorized bases to determine their risk to radon based on sampling. Appendix E provides general information about radon sampling consults.

Additional resources are available on the ESOH Service Center Radon webpage, along with a list of bases that have already determined their Radon Risk Category. Document sampling results using the DOEHRS Radon Quick Start Guide (QSG).

Radon surveys should follow recommendations provided by the Environmental Protection Agency (EPA). Although the EPA does provide exposure guidelines, there are no EPA regulatory limits regarding naturally occurring radon exposure for non-occupational settings. However, employers are responsible for the presence of radon in any structure that exposes employees to hazardous concentrations of airborne radiation.1 The AF sets mitigation thresholds and associated timelines in Air Force Manual (AFMAN) 48-148.

1 OSHA. Consultative letter to U.S. Army Corps of Engineers. “ https://www.osha.gov/laws-regs/standardinterpretations/2002-12-23

1 INTRODUCTION

https://www.osha.gov/laws-regs/standardinterpretations/2002-12-23 https://www.osha.gov/laws-regs/standardinterpretations/2002-12-23 contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

1.1 Changes from the BE’s Guidebook for Radon Management, 2nd Edition

This guide has been substantially revised. Changes include:

• Added flowcharts to help Installation Radiation Safety Officers (IRSOs) determine what sampling is required for their installation.

• Clarified requirement for IRSOs to enter radon samples in Defense Occupational and Environmental Health Readiness System (DOEHRS) according to AFMAN 48-148 para 7.3.5.

• Removed statement that USAFSAM/OEC will contact MAJCOM BE when negotiating dates for radon sampling.

• Discussed Air Force’s (AF’s) decision to adopt WLM/yr instead of pCi/L, and established criteria to reflect this change in units.

• Increased use of hyperlinks to key sections within this guide for ease of use.

• Removed redundant checklists

• Migrated Base Risk Categories to ESOH Service Center to update as necessary.

• Reorganized/rephrased sections to improve readability and clarity.

• Expanded Quality Assurance (QA)/Quality Control (QC) section to increase confidence in sampling results.

1.2 Working Level Months in a Year (WLM/yr)

Residential radon and its progeny are traditionally measured in pCi/L. EPA recommends mitigating all homes likely to exceed 4 pCi/L.2 To more accurately account for occupational exposure, the AF has implemented quantifying this exposure in WLM/yr.

Assuming a space is occupied 100% of the time with an equilibrium factor of 0.4, residential exposure to 4 pCi/L is approximately the same as 0.82 WLM/yr.

Table 1. Recommended Building Occupancy Factors Building Types Hours Occupied in a Year Reasoning Workplaces 2,000 Accounts for a 40-hr work week.

Housing Units 8,760 Considers rare potential for dependents to remain in area 100% of time

Dormitories 6,760 Unlike housing units, single Airman dorms are expected to be vacant during the 40-hr work week

The length of time (in hours) that occupants remain in a building is referred to as the occupancy factor. Table 1 provides a list of assumed occupancy factors based on the

2 EPA. Citizen’s Guide to Radon. https://www.epa.gov/sites/production/files/2016- 12/documents/2016_a_citizens_guide_to_radon.pdf https://www.epa.gov/sites/production/files/2016-12/documents/2016_a_citizens_guide_to_radon.pdf https://www.epa.gov/sites/production/files/2016-12/documents/2016_a_citizens_guide_to_radon.pdf contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

type of building monitored, but this should be based on information gathered during the sampling event’s planning phase. Considering occupancy factors enables the AF to more appropriately characterize exposure risk to radon and better manage resources.

Rather than resample all bases for comparison to the mitigation criteria laid out in AFMAN 48-148 Table 7.1, it is advisable for installations to calculate existing sampling data in WLM/yr to determine if risk is appropriately characterized. See Calculating Radon Concentrations section for step-by-step details to accomplish this.

1.3 USAFSAM Support

The USAFSAM Occupational and Environmental Health Department (USAFSAM/OE) plays a key role in the AF radon program. They provide general oversight for all AF radon sampling, to include reviewing past sampling data, recommending sampling strategies, prioritizing/scheduling sampling events on the basis of risk, providing the equipment necessary to execute an installation sampling event, and offering consultative advice to help the installation BE resolve any issues they encounter.

Refer questions regarding radon assessment and mitigation to USAFSAM/OE through:

Environmental, Safety, and Occupational Health (ESOH) Service Center:

Toll Free 1-888-232-ESOH (3764)

Commercial (937) 938-3764

DSN 798-3764

Email: esoh.service.centr@us.af.mil https://static.e-publishing.af.mil/production/1/af_sg/publication/afman48-148/afman48-148.pdf mailto:esoh.service.centr@us.af.mil contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.1 Reasons for Sampling

Before performing radon sampling, it is important to decide what goal sampling is meant to achieve. Although this may seem obvious, many bases request sampling unable to answer this question. Table 2 lists the common reasons for performing radon sampling.

Most active duty bases already have records of Initial and Detailed Assessments during the AF Radon Assessment and Mitigation Program (RAMP) from 1987. Appendix A contains a methodology laying out how each of the common assessment types relate to create a comprehensive radon sampling program. Installations with no established risk category should progress through this methodology to characterize their installation’s radon risk. This chart can also be used to assist categorized bases with determining how to manage their installation’s radon program.

If an Initial Assessment was never performed, prioritize sampling based on neighboring bases’ risk categories in conjunction with the interactive Environmental Protection Agency (EPA) Radon Zones Map, or Outside Continental Unites States (OCONUS) equivalent provided in Appendix D. After an Initial Assessment is complete, it may be necessary to perform a Detailed Assessment to confirm any elevated results.

2 PLANNING A SURVEY

contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

Table 2. Common Assessment Types Radon

Assessments Requirement Test Type Description/Reason for Sampling

Fo r b as es w ith n o ca te go ry

Initial

Required for all bases to assess radon risk in DoD housing, and all

CDCs, and DoDEA schools. Should also test a sample of occupational settings with testable rooms.

Long-term >90 days

Determines Base Risk Category. Used as a screening tool to identify a radon problem at bases not previously tested. Test consists of >30 different locations.

Detailed One-time requirement for all bases with measurements >0.8 WLM/yr

Long- and Short-term

Determines Base Risk Category. Sample all structures containing testable rooms on base for 1-year. If any structures previously measured >4 WLM/yr, an additional 30-day sampler should be placed in each building alongside long-term samplers. Initiate mitigation in any buildings with short-term samples >4 WLM/yr, otherwise mitigation is based on a full-year sample result.

M iti ga tio n Diagnostic Measurement Required Short-term

2-15 days Test to make modifications and determine system effectiveness. See UFGS 31-21-13 para 3.4.2.1

Post- Mitigation Required

Long-term 240-365 days

Reportable test started within 90-days after mitigation has concluded. See UFGS 31-21-13 para 3.4.2.2

Supplemental As needed Short- or Long-term

Repeat survey as a replacement for missed rooms, lost detectors, or invalid sample results

Confirmation As needed Short- or Long-term

To confirm results from a previous survey when elevated radon levels were detected

Special Request As needed Short- or Long-term

Testing a room or building based upon a stakeholder’s request (facility manager, IRSO, employee complaint)

New Construction Required for new buildings with testable rooms at High or Medium Risk Bases4

Long-term Perform sampling no sooner than 1 year after construction concludes

Renovation Retest

Recommended for buildings with testable rooms at High or Medium

Risk Bases5 Short-term A retest after significant renovation or HVAC replacement

Periodic Retest Recommended for buildings with testable rooms at Medium- and

High-Risk Bases Long-term

Testing performed after Initial, Detailed, and Post-Mitigation Assessments were performed to ensure radon levels are acceptable and mitigation is operational. See Periodic Retesting section

School/Housing As needed for installations missing sampling results for DoD housing, CDCs, or DoDEA schools Long-term

If a categorized base missed sampling in any of these critical buildings follow procedures in Number of Rooms Locations to Test section

3 AFMAN 48-148. 2020. Ionizing radiation protection. para. 7.3.2 4 UFGS 31-21-13 pg. 3. https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf 5 AFMAN 48-148. 2020. Ionizing radiation protection. para. 7.3.2 https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.2 Determining if Sampling is Required

With the exception of deployed locations, all AF installations with buildings containing testable rooms should sample to determine if unacceptable radon exposures exist.

Even installations previously classified as Low-Risk are advised to consider additional radon sampling in key areas, including underground complexes/facilities, bunkers, nuclear missile silos, etc.

All AF installations MUST have long-term radon assessments for structures supporting Department of Defense (DoD) housing, child development centers (CDCs), and DoD Education Activity (DoDEA) schools to make available for building occupants.6

Mitigation systems shall be installed where elevated radon levels are confirmed above the 0.8 WLM/yr action level.

All new building construction, in bases located within EPA Zone 1 or where an average of >4 pCi/L is expected, should have passive mitigation systems incorporated into the building’s design.7 After a building is mitigated, a Diagnostic Measurement, and Post- Mitigation assessment must be performed to ensure the system remains effective.8 Investigate with the contracting office, to identify what sampling was performed, and determine if BE needs to perform sampling9. See Analyzing Test Data from Other Sources, if sampling was already performed by a non AF organization. It is advisable to perform Periodic Retesting every 5 years to verify radon reduction remains successful10.

Diagrams are available in Appendix A, B, and C that show the process for determining if sampling is necessary.

2.2.1 Determine the Risk Category

It is important to know an installation’s dynamic risk category––high, medium, or low, as this affects what additional program requirements are necessary and whether mitigation is required. USAFSAM tracks risk category information as determined by ongoing radon sampling events, but radon records are individually managed by installation BE.

When sampling, the highest confirmed radon result at the installation among ALL sampling results determines the base’s NEW radon risk level. After a problem building is mitigated or demolished, the installation’s category remains unchanged because the potential for buildings on the installation to exceed 0.8 WLM/yr has not changed.

6 AFMAN 48-148 para 7.2.1.

7 UFGS 31-21-13 pg.3. https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf 8 UFGS 31-21-13 para 3.4.2. https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf 9 UFGS 31-21-13. 2018. https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf 10 UFGS 31-21-13. 2018. pg.3 and 1.4.1.

https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf https://www.wbdg.org/FFC/DOD/UFGS/UFGS%2031%2021%2013.pdf contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

Table 3. Risk Categories Risk

Category Criteria Recommendation

High Sampling results >4 WLM/yr

Mitigation required IAW AFMAN 48-148 Table 7.1.

Periodic Retesting recommended every 5 years. Base should develop a formal written sampling plan establishing what buildings to test at what time intervals.11

Medium Sampling results >0.8 WLM/yr to 4 WLM/yr

Mitigation required IAW AFMAN 48-148 Table 7.1.

Periodic Retesting recommended every 5 years.

Low Sampling results <0.8 WLM/yr

At minimum, an Initial Assessment should be performed to characterize risk including DoD Housing, all CDCs, and DoDEA schools. If base does not have these buildings, sampling is still recommended at 10% of all buildings containing testable rooms or >30 separate locations.

2.3 Selecting Structures to Monitor

The following guidance applies to all bases performing Initial, Detailed, and Periodic Assessments.

2.3.1 Determine the Base Size

The base’s size affects the ideal sampling approach. Generally, sites with 50 buildings or less, such as most Air National Guard training facilities or remote communications sites, are considered small bases.

2.3.2 Develop the Sampling Plan

It is advisable for small bases that have never performed an Initial Assessment to measure all buildings containing testable rooms, but this may be impractical for large bases.

Small bases may proceed to the Select Rooms to Monitor section. Large bases may continue to the Develop Sampling-Sites and Select Buildings to Monitor sections below.

11 AFMAN 48-148 para. 7.3.1 contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.3.3 Develop Sampling-Sites

Dividing the installation into sampling-sites enables a base to divide large bases into more manageable, relatively similar sections. Although USAFSAM/OE can provide general guidance and review proposed sampling sites, large bases should work with installation Civil Engineering (CE) since they maintain the specific information required for all buildings and related plans for the base. After sampling-sites are determined, BE can proceed to test a representative number of structures within each one. Samples should be collected from 10% (a statistically significant number) of the structures in each of these sampling-sites.

Bases can develop sampling-sites by considering the following factors:

• Base Subdivisions. This consists of natural groupings of buildings with similar construction, uses, features, and dimensions. Reviewing base maps will often reveal ways to subdivide an installation with these similar structures making-up the ‘core’ of the sampling-site. Examples of base subdivisions can include dormitories, flight line maintenance buildings, and different housing areas.

• Areas Separated by Distance. Dividing bases into two or more geographic areas is also common. For example, the Hanscom AFB BE shop provides oversight for Cape Cod Air Station, New Boston Air Station, Rome Laboratory, and Sagamore Hill. Each location must have a separate sampling plan.

• Geology and Topography. Examine the geology and other conditions present when determining initial sampling-sites. Examples of other (non-geologic) conditions to consider include buildings over low points like wetlands, and valleys or highpoints such as landfills, and other filled areas. These factors affect how radon moves and collects in an area. If the geology, among other conditions, are the same for two adjacent sampling-sites, consider combining them into one site.

If the geology and other conditions differ within a sampling-site, consider subdividing the sampling-site.

2.3.4 Selecting Buildings to Monitor in a Sampling-Site

Give priority to buildings at higher risk likely to have elevated radon concentrations and/or containing sensitive populations.

High Priority Testable Buildings include:

• Housing, CDCs, DoDEA schools, and other locations with sensitive populations12.

• Buildings with occupied underground facilities (underground complexes, bunkers, nuclear missile silos, etc.)

• Buildings with energy-efficiency modifications that increase their “air tightness.”

12 AFMAN 48-148 para 7.2.1 contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

Areas having 24-hour operations are also good candidates for sampling. A representation of the buildings on the installation should be tested to better characterize radon exposure.

2.4 Select Rooms to Monitor

The initial objective when monitoring a building is to determine if any occupied room in the building exceeds guidance levels, therefore the building requires mitigation. For single-family dwellings, this is simple, but that is not the case for large, complex buildings.

2.4.1 Testable Rooms Criteria

A testable room must be occupied for more than 4 hours per day, or is readily capable of being occupied (i.e. living rooms, bedrooms, dens, offices, or barracks). Examples of rooms readily capable of being occupied include vacant billeting rooms, vacant offices, meeting rooms, or spaces that could easily be converted or occupied.

Testable rooms should also meet one of the following criteria:

• It is a basement or other underground location. This includes rooms that are partially underground i.e., built into a hillside (Not applicable to schools. See number of rooms to test for schools.

• It has ground contact (wall, floor, or ceiling) or is located over an unventilated crawlspace.

• Occupied service bays such as motor transport buildings, and hangars (only if the bay doors are closed for ≥4 hours/day).

• Additional rooms the AF may choose to test include ground-contact hallways, stairwells, and common areas.

2.4.2 Non-Testable Rooms/Locations

Unless for diagnostic purposes, the following room types should not be tested: kitchens, bathrooms, gear lockers, closets, dedicated storage rooms, elevator shafts, crawl spaces, or unoccupied areas like mechanical rooms. According to the manufacturer, areas frequently exposed to the outdoor environment should not be tested including temporary facilties, and tents. Dusty areas should only be tested after placing opened samplers in Tyvek bags. This will allow radon gas to penetrate while discouraging dust and other small particles from entering and skewing sampling results.

2.4.3 Number of Rooms/Locations to Test

The number of testable rooms necessary to characterize a building is determined based on several factors, including the type of assessment performed, and resources available. The testing plan should provide a reasonable, upper estimate of the average contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

annual radon concentration in that structure. Installation CE maintains blueprints, diagrams, specifications, and geological surveys necessary for BE to accomplish this.

Use the following guidance to perform building specific surveys including School/Housing Assessments and other Special-Request Assessments.

For Privatized Homes:

Radon sampling must be accomplished by the project owner, unless otherwise specified in a Memorandum of Understanding/Agreement (MOU/MOA) between the owner and

BE13.

For Non-Privatized Homes:

• Although it is ideal to sample all testable rooms in single-family housing units, this may not feasible. At minimum, test the primary living space, such as the family room or master bedroom in each of these residences.

• Similarly, for apartments, dorms, and similar multi-story housing units (townhomes, condominiums), sample each testable room in a representative sample of apartment or housing units if resources are available. If sufficient resources are unavailable, sample at least one testable room in each apartment or townhome in the complex. For example, with an apartment building containing 10 units, if only 5 have testable rooms, those 5 apartments require monitoring in at least 1 of those testable rooms.

• Follow this guidance for all testable rooms in other small structures similar to housing units.

For Workplaces and Similar Facilities:

• Radon sampling should be performed in at least 1 test location per 2,000 ft2. 14

• Contact USAFSAM/OE for guidance in rooms ≥ 10,000 ft2 (e.g., warehouse bays), for complex and/or very large buildings.

• If you determine it is appropriate to sample all testable rooms, ensure you provide justification for this request. Your assigned consultant will provide a recommendation, but ultimately, the IRSO makes the final decision.

13 AFMAN 48-148 para 7.4.6 14 ANSI/AARST. 2014. Protocol for Conducting Measurements of Radon and Radon Decay Products in Schools and Large Buildings https://standards.aarst.org/MALB-2014/index.html contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

For CDCs, and DoDEA Schools, USAFSAM recommends:15

• Sampling all frequently occupied testable rooms on all floors that are either underground, in contact with the ground, or above non-testable areas, such as empty crawl spaces or underground duct work.

• Large rooms or open areas (e.g., gyms, cafeterias, auditoriums) will have one testing location per 2,000 ft2.

If the facility has multiple floors, all upper floors will be tested as follows:

• Test 10% of rooms, with a minimum of at least one room on each floor

• Upper level rooms sitting above non-tested rooms on ground or sub-ground floors should be tested (e.g., test classroom on second floor that sits above a storage room on the first floor)

• On each upper floor, do not test rooms adjacent to those already tested on the previous floor. For example, if you test the northwest and southeast corner rooms on floor 2, you should test northeast and southwest rooms on floor 3 (Figure 1)

2.5 Short-Term vs Long-Term Monitoring

There are two different measurement types: short- and long-term (see Table 4). The Sampling Equipment Information section below discusses equipment in greater detail.

15 ANSI/AARST. 2014, Protocol for Conducting Measurements of Radon and Radon Decay Products in Schools and Large Buildings and AFMAN 48-148 para. 7.2

Figure 1. Adjacent Rooms on Upper Floors contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.5.1 Short-Term Measurements

The AF uses short-term measurements to collect radon samples for 7-15 days. Although it is permissible to read samplers in as few as 2 days after deployment, these early measurements are less reliable. Short-term samplers are sensitive to radon exposure even at lower levels. For these reasons, short-term measurements may provide an inaccurate representation of average annual radon concentrations, but they are excellent for screening purposes. Avoid short-term testing during periods of extreme weather (i.e., heavy rain or snow storms, very high winds, or similar storm conditions).

Short-term sampling MUST be performed under closed-building conditions. Provide justification to USAFSAM/OE if you are requesting short-term monitoring for purposes other than screening or evaluating radon mitigation effectiveness.

2.5.2 Long-Term Measurements

Long-term measurements are less sensitive to fluctuations in radon levels and provide a more stable and accurate representation of the average annual radon concentration in a structure. For this reason, long-term sampling equipment must be used for compliance sampling. Long-term measurements require at least 90-days of sampling and SHOULD take place, if possible, under closed-building conditions. If this is not practical, conduct testing when the building is most closed – winter in cold climates, summer in hot climates. If the test is 1 year in duration, closed-building conditions are not required.

Table 4. Difference Between Short-Term and Long-Term Measurements Item Short-Term Monitoring Long-Term Monitoring

Duration At 7-15 days At least 90 days and up to 1 year Accuracy Greater sensitivity More stable and accurate, less sensitive Measurement Conditions2

• Closed building is required. Windows and doors remain closed as much as possible.

• No monitoring during periods of extreme weather.

• If testing period is < 1 year, recommend closed-building conditions; if this is not practical, test when the building is most closed.

• If testing period is for 1 year, closed-building conditions are not necessary.

Uses • Screening purposes

• Evaluating radon mitigation effectiveness

Preferred method for all monitoring.

Required for establishing compliance or base’s risk category Note: Radon testing should not occur if significant building renovations or heating, ventilation, and air conditioning (HVAC) replacements are proposed/occurred during the test period.

contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.6 Closed Building Conditions

A structure’s radon levels will vary by the time of day, building conditions (closed windows versus open, ventilation), and the time of year. ‘Closed-Building Conditions’ refers to closing off- a building for as long as possible, to stabilize radon levels and entry rates increase measurement reproducibility.16 This reduces sampling variability caused by extreme fluctuations in outside radon levels, as well as any dilution that may occur.

This must be accomplished at least 12-hours before deploying sampling equipment.

The most effective way to accomplish this is to begin sampling early on a Monday morning or on the first day after a long holiday. Normal air conditioning systems can still be operated during this sampling event, but without fresh air supplied intake. In other words, supply fans that bring in air from the outside should be turned off. Exterior doors and windows must not be propped open during testing, but immediate entry or exit is permitted. American Association of Radon Scientists and Technologists (AARST)/ American National Standards Institute’s (ANSI’s) Radon Measurements in Schools and Large Buildings Table 6.0A and 6.0B provide detailed closed-building protocols that should be inspected during sampling deployment/collection. It is critical to maintain closed-building conditions during short-term sampling, but this is only recommended for long-term sampling.

Note: Do not turn off any radon mitigation systems during the survey, since sampling these areas intends to confirm radon levels are successfully reduced.

When planning the radon sampling event, advise Facility Management staff regarding their responsibilities: to inform building tenants not to disturb samplers, to obtain closed-building conditions, and to report incidents where closed-building conditions/tampering may affect testing.

2.7 Normal Occupancy Conditions

As with other sampling events, radon sampling should be performed during normal-operating (occupancy) conditions. For example, do not begin sampling a month before a new unit is reassigned to work in the facility. Minor fluctuations in building occupancy during the survey is expected, but extreme changes will skew radon measurement accuracy. This will also affect the occupancy factor required to calculate the expected WLM/yr exposure.

16 ANSI/AARST. 2014. Protocol for Conducting Measurements of Radon and Radon Decay Products in Schools and Large Buildings. Para. 6.1 https://standards.aarst.org/MALB-2014/23/index.html#zoom=z https://standards.aarst.org/MALB-2014/23/index.html#zoom=z contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

2.8 Requesting Sampling Equipment from USAFSAM

All requests for radon monitoring must be submitted through the ESOH Service Center as a “Request for Radon Sampling at (name of base)” along with the completed USAFSAM Radon Sampling Strategy spreadsheet as an attachment. Once this request is received, USAFSAM will contact the installation BE/requestor to coordinate any necessary radon monitoring.

mailto:esoh.service.center@us.af.mil https://hpws.afrl.af.mil/dhp/OE/ESOHSC/pages/index.cfm?id=728 contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

3.1 Placing Detectors in the Room

After selecting rooms for testing, deploy samplers in accordance with ANSI/AARST guidelines.

Specifically:

• Select a testing location that reduces the probability of disturbance.

• Do not place the device within 3-feet of drafts caused by fans or HVAC systems.

• Do not place or hang the detectors on lights or fire sprinkler fixtures.

• Do not put the detectors inside containers including drawers ,cabinets, buckets or lockers because this will skew the sampling results.

• Do not place devices near radiation sources including natural stone, rock collections, granite, hearths and slate pool tables

• Do place devices between 2 and 8 feet above the floor, greater than 4-inches away from objects, greater than 3-feet from exterior doors and windows, and 1-foot from any outside wall or cracks in the foundation.

• Do place collocated duplicate detectors within 4 to 6 inches of each other.

3.2 Minimizing Detector Loss

Most detector loss (Figure 2) can be prevented by exercising the following precautions:

• Provide the occupant with notification similar to Figure 3 during deployment and attach as a doorhang to the room, and/or in close proximity to active samplers

• Inform contractors and base personnel that radon testing is in progress and the testing devices should not be disturbed.

• Place detectors away from major foot traffic areas to ensure they will not be bumped during the test period.

3 PERFORMING A SURVEY

Figure 2. Leading Causes of Sampler Loss contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

During detector placement, you may also wish to provide occupants with a handout containing information about radon such as the EPA’s “Citizen’s Guide to Radon.”

Figure 3. Notice to Tenant

Notice to Tenant

DO NOT TOUCH, MONITORING IN PROGRESS

This detector is testing the environment for radon gas and is not harmful. It must remain in place for a minimum of __ days. Contact Bioenvironmental Engineering with any questions you may have.

Date chamber was opened Recommended date for return

Bioenvironmental Engineering POC:

Name: Phone number: _________ contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

3.3 Sampling Equipment Information

After the proposed radon monitoring request is reviewed by the USAFSAM consultant, they will ship: a voltage reader kit, a combination of electrets, and chambers. Equipment distribution depends on the AF's greatest need, as determined by USAFSAM/OE.

Installation BEs may always chose to contract technicians or laboratories certified through National Radon Proficiency Program (NRPP), National Radon Safety Board (NRSB) or the state. The Analyzing Test Data from Other Sources section discusses what information these organizations must provide.

3.3.1 Voltage Reader Kit

All bases will receive a voltage reader kit. Each kit contains one reader (Figure 4), one Zero electret, and two Reference electrets.

CAUTION - Electrets have a charged surface and should not be touched as it will discharge the voltage, rendering the device useless.

• Zero Electret. The Zero electret is part of the QA/QC program. It is used to verify the Voltage Reader reads a zero-volt charge accurately and the person performing the sampling is doing so correctly. This measurement should not exceed 5 volts.

NOTICE - If readings exceed this range, and/or are not reproduceable contact your USAFSAM consultant immediately because this will render any further readings unusable.

Figure 4. Voltage Reader contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

• Reference Electrets. Reference electrets are used as part of the QA/QC program. It is used to verify that the reader is functioning properly, and the person performing the sampling is doing so correctly. These electrets are highly-stabilized to reduce the voltage-loss that occurs from contact with radon. These electrets are read in a lab and certified accurate within +/- 3 volts.

NOTICE - If readings exceed this range, contact your USAFSAM consultant immediately because this will render any readings you make unusable.

3.3.2 Field Electrets

These are shipped from USAFSAM with a plastic protective, screw-on cover, referred to as a “Keeper Cap”. In most cases, short-term sampling uses blue-labeled electrets (ST electrets) and long-term sampling uses red-labeled electrets (LT electrets). The acceptable measurement range is between 100 Volts and 750 Volts17. Electrets (Figure

5) come from the manufacturer fully charged with about 750 volts. As they come in contact with radon and its progeny, a small voltage is discharged from the electret’s charged surface. Radon measurements are determined by comparing the ending voltage measurement against the initial voltage measurement, then calculating the voltage loss.

For step-by-step instructions on how to read Zero, Reference, or field sample electrets, see Radon Sampling Instructions.

3.3.3 Chambers

The AF uses two different types of ion chambers for radon sampling: S-Chambers and L-Chambers.

17 Rad Elec Inc. E-PERM System User’s Manual [v 3.3.1]. p. 26

Figure 5. Electrets contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

S-Chambers

These bell-shaped ‘Standard’ chambers (Figure 6) are designed primarily for short-term sampling, but are usually provided for long-term sampling, for ease-of-use, and to prevent the loss that occurs from using the smaller L-Chambers. These chambers can be read and prepared in the BE shop, transported to the sampling site, then activated in the sampling area To operate - Take the initial reading at the BE shop, securely affix the electret into the bottom of the S-Chamber, then transport to the sampling location. To place the chamber in test mode, completely unscrew the cap allowing the top to extend upward. If this is a field- or lab-blank, securely affix the electret to the bottom as normal, but leave the cap completely closed during the survey

L-Chambers

L-Chambers come in two different styles: L-O and L-OO and are ONLY used for long-term sampling.

L-O Chambers

L-O Chambers (Figure 7) are dome-shaped and have a small hole on the side that must not be covered. These are rarely issued to bases because they are less versatile than L-OO chambers.

To operate - Unscrew the electret cap in the sampling area. Simply collect the initial electret voltage, securely affix the electret into the bottom of the chamber, and IMMEDIATELY place for sampling. You cannot use these chambers for field- or lab-blanks, but you can place the electret in the area with its “Keeper Cap” on to accomplish this.

Figure 6. S-Chamber (Open chamber on left, closed on the right)

Figure 7. L-O Chambers are Always 'on' contractors; Administrative or Operational Use; 27 April 2021. Other requests for this document shall be referred to USAFSAM/OEC, 2510 Fifth St., Bldg. 840, Wright-Patterson AFB, OH 45433-7913.

L-OO Chambers

These chambers (Figure 8) look similar to L-O chambers but have a long flat plastic piece affixed to it with a metal clip. Unlike the L-O chamber, this device has a ‘closed’ and an ‘open’ feature. For this reason, it may be read in the BE shop then transported to the sampling location where it is activated.

To operate - Place in test mode by removing the pin, moving the chamber to reveal the complete slide bar, then replace the pin. If using as a blank, the slide bar should be exposing a circular hole.

3.3.4 Combining Chambers and Electrets

Once an electret is affixed to a chamber, the sampler is considered an Electret-Passive…