THE FLORIDA RADON RESEARCH PROGRAM 1989-1995: A REVIEW OF SCIENTIFIC ACHIEVEMENT Kaiss K. Al-Ahmady, Walter G. Klein, Norman M. Gilley State of Florida, Department of Health and Rehabilitative Services Office of Environmental Toxicology, Radon and Indoor Air Toxics Tallahassee, FL ABSTRACT To reduce the exposure of Florida residents to radon, the Florida Legislature passed a 1988 bill requiring the development of standards for the construction of radon resistant new buildings and standards for the mitigation of radon in existing buildings. The Florida Department of Community Affairs (DCA) placed in charge of this development, launched a long-term, multi-million dollar state funded research program known as the Florida Radon Research Program (FRRP). From the beginning, DCA sought the cooperation of the United State Environmental Protection Agency (USEPA), the Florida Department of Health and Rehabilitative Services (HRS),the Florida State University System, and other participants nationwide for completion of the program. In late 1995 the FRRP completed its objectives and over the six-year period made a significant contribution to the knowledge and techniques in understanding and controlling indoor radon. By all measures, the FRRP was one of, if not the, largest radon research programs in the United States. The extensive scope of the FRRP covered the following related fields: soil-gas transport, soil and construction materials, radon entry and indoor radon modeling, mitigation techniques, building systems and environment, radon potential maps, and the development of radon-resistant construction standards for both residential and non-residential buildings. Most of the FRRP research results have been published in the USEPA report system and in national and international meetings and journals. Forty-five of the FRRP reports have been published by the USEPA as of April 1996. These published reports are tabulated and summarized in this paper. The tabulations are organized into the report title, authorfs), the USEPA report number, and include a brief description of the content of the report. This paper represents a significant resource for radon and indoor air professionals and interested parties in related fields. INTRODUCTION AND APPROACH In 1989 the Florida Radon Research Program started under the administration of the Florida DCA, Division of Codes and Standards. Many researchers from Florida universities and research centers, government agencies, and private industry participated in the research program for approximately six years. The main objective of the FRRP was the development of new radon-resistant construction standards for residential and large buildings in Florida. To provide for a quick start, at the early stage, the FRRP was established with startup funding to the State University System (SUS) in Florida. The Board of Regents of the SUS was to provide a preliminary draft building code to the DCA, which would be used in the initial administrative rule process to set the standards. Florida DCA process was structured under the idea that FRRP is not only their project, therefore, participation from USEPA, HRS,and other organizations was seriously sought from the beginning. During the span of the project, significant assistant, both technical and administrative, was received from the USEPA. The latter was delivered through the participation of the National Risk Management Research Laboratory (formerly Air and Energy Engineering Research Laboratory) of the Office of Research and Development (ORD) at Research Triangle Park in North Carolina. many In the process of achieving the main objective of the FRRP, research were administered, organized, and conducted virtually to cover all theoretical and experimental aspects of concern to the indoor radon problem and its interaction with building construction, systems, and the environment. For the purpose of this work, and to describe the nature of research covering, the subject of the main delivery of the research reports is generally classified into eight categories as the following: (A) soil/fill/construction materials characterization, evaluation, and modeling; (B) buildings and buildings support systems (BSS) characterization, evaluation, and modeling; (C) foundation and - 1996 International Radon Symposium IP 1.1 building construction standards; (D) radon potential and protection mapping development; (E) radon measurement methodology and standards; (F) radon source-term and entry measurement, modeling, and computer codes; (G) indoor radon driving forces and concentration modeling and computer code; and (H) radon mitigation and control systems evaluation, development, and standards. Research results and outcome from the FRRP have been published through the ORD system, and in national and international conferences and journals. However, the ORD publications provide for a systematic and uniform covering of the FRRP research results since final reports from all research contracts administered through the program are due to the Florida DCA and/or the USEPA under the contract requirement. As of April 1996, Forty-five FRRP-generated reports have been published by the USEPA. All publications were peer and administratively reviewed by the USEPA and other reviewers in accordance with the agency policy. Further all mentioned reports in this work are available to the public through the National Technical Information Services. There are over twenty other FRRP reports which are in various stages of the review process and completion but have not yet published. Those reports are not included in this work. RESULTS A total of forty-nine volumes, from forty-five research reports, were published between 1991 and April of 1996 have been reviewed and tabulated. The last row of Table 1 shows the number of generated reports in each of the FRRP operating year based on the USEPA publications. Table 1 also shows the distribution of the general subject of main delivery of research reports (according to the classification categories A-H discussed in the previous section), for the USEPA-published research reports that were generated in the FRRP between 1991 and April 1996. It should be noted that classification of the research subject is based on the main component in the research work not the research application As seen in the table, the majority (20%) of current standing of published reports foul into category F; radon-source term and entry measurement, modeling, and computer codes. The minority covering is that of the subject of category H (6.7 %).. Research subject of category A; is the second in volume and forms 15.6% of the current standing of published reports. It followed by categories C and D subjects with 13.3% , category G subject with 11.1%, and category E subject with 8.89% covering. Table 2 shows the list of the current standing of USEPA-published FRRP research reports. The title and author (s) of the report are shown in the first column, followed by the USEPA report number in the second column. A condensed description about each report is shown in the third column. For the purpose of this work and due to the limitation of size, the description is designed to deliver brief statement describing the report with the objective of providing input to what is there rather than what have been found. Therefore, the description column shows a condensed statement about the content of the report rather than its major findings. Table 1: Distribution of the general subject category of the FRRP USEPA-published research reports between 1991 and April 1996. The last row shows thinumberof report published for each year. I - H Number of Reports 1 8 1 6 0 o 3 9 1 1 3 1 6 - l 1996 International Radon Symposium IP 1.2 l 1 Â Table 2: A description of the USEPA-published research reports generated by the Florida Radon Research Program between 1991and April of 1996. TitleJAuthor (s) correlation of Florida Soil-Gas Permeabilities With Grain Size. Moisture, and Porosity. V.C. Rogers and K.K.Nielson Document Number : j EPA-60018-91439 1 : Proceedings of the Workshop on Radon Potential Mapping Florida radon Research Program. Description Presents a new correlation for predicting gas permeabilities of undisturbed or recompacted soils. This correlation is based on new in-situ Florida measurements and is a function of average yain diameter, moisture saturation fraction and porosity. Radon transport in .soil is highly dependent on permeability. ................... .........*........... ............................ ............................... ..... .................--. Documents a workshop on radon potential mapping in Gainesville, FL,April 20, 1990. Presented the technical basis ! for defining an indoor radon potential maps and reviews K.K. Nielson and V.C. Rogers existing radon maps and usage of aeroradiometric, geological, ! . . . , ..................................... radon, and other data. .....................................................................................................--......-.......-....--... ,.................................................. indoor ............ "........................................................... ..."........... EPA-60019-9 1-044 I Feasibility and Approach for Mapping Radon Potentials in Florida. K.K.Nielson and V.C. Rogers EPA-60018-9 1-046 i i I A review of previous radon potential mapping strategies and an evaluation of mapping strategies suitable for application to radon-resistant construction in Florida. Source, house and time variations influencing indoor radon are considered to quantify orobable indoor radon concentrations. A review and evaluation of technologies for measuring radon in soil gas. The measurement parameters, equipment needs, H. E, Rector procedures and concepts to convert the data to estimates of radon -presented for the methods evaluated. ....................are .................. ................................................................................... .............................................. "............................................................... -........."....... .............................................. .........potential Recommended Foundation Fill Materials Construction Standard I EPA-60018-9 1-206 One of a series of five reports recommending building of The Florida Radon Research Program. construction standards. Soil radon and radium limits are presented as a function of soil permeability. Information on V.C. Rogers and K.K. Nielson rates...into soils is included. ........................................................................................................................................................................................ ....... radon ..............entry ................... .....dwellings . .................and .......--Florida .........-............................. ........... An Assessment Soil-Gas Measurement Technologies. 1 1 EPA-60018-9 1-050 -..- Recommended Sub-Slab Depressurization Systems Design Standard of the Florida Radon Research Program. I EPA-60018-9 1-208 D.E. Hintenlang and C.E. Roessler I j 1 Development of Alternate Performance Standard for Radon EPA-60018-91-210a Resistant Construction Based On Short-Tenn/Lone-Term Indoor 1 One of a series of five reports recommending building construction standards. The design elements of the recommended standard for sub-slab depressurization are presented along with information supporting the inclusion of each of these elements. ..... ."...................................-......................................................... ........... A study of long and short term measurements in 80 Florida houses. It evaluates the coefficient of variation.for ........................................................... ....-................................... ,..-.the ....different .........., TitldAuthor (s) - Xadon Concentrations Volume 1 - Technical Report. Document Number 1 Description LD. Williamson, S. E. McDonough ,C.S. Fowler measurement periods to establish confidence limits for short term measurements. This report indicates a seasonal effect on average radon. ...................................................................................................................................... Development of Alternate Performance Standard for Radon Resistant Construction Based on Short-Tenn/Long-Term Indoor Radon Concentrations - Volume 2 Appendices Appendices to a study of long and short term measurements in SO Florida houses. These appendices include a summary and analysis of a Gainesville study, measurement data and quality control data. .............................................-......................................................................................... - - A.D. Williamson, S.E. McDonough, C.S. Fowler ,......................... ...................... .......................................... ............................................... - Standard Measurement Protocols Florida Radon Research Program. A.D. Williamson and J.M. Finkel ............................ ................................................-..................................................... " Radon Pressure Differential Project, Phase I, Florida Radon Research Program. J. B.Cummings, J.J. Tooley, N.Moyer .................... .............................".......................................................-.......................-... Recommended Standard of the Florida Radon Research Program J. B. Cummings ........................... Modeling Radon Entry Into Florida Houses With Concrete Slabs and Concrete-Block Stem Walls. K.L. Revzan, W.J.Fisk, R.G.Sextro ................................................................................................................................... Guidance For Research House Studies of The Florida Radon Research Program Volume 1: Research Plan. - K. J. Gadsby and T.A. Reddy ..................................................... "....,,",....... ................................................................. ....................................................... ................................................................................ A manual for FRRP soil and building measurement procedures. [t contains field sampling protocols for soil gas permeability, Rn concentration, in-situ soil density, soil classification and penetrometer analysis; and diagnostic procedures for sub-slab Rn and communication, differential pressure and leakage measurements. ......................................................... ..........-...................................................... . . . . . . . . . .n Presents pressure differential results performed in 70 new (5 years or less) homes located in central Florida. Measurement were taken between the interior and outdoors, sub-slab area, and other locations. An average 7.23 ACH at 50 Pa. was found using blower door testing with 11-6% of the leaks in the duct system. ............................................,.. ..................................................................................... One of a series of five report which recommended building construction standards developed by the Florida Radon Research Program. It presents recommendation for the heating, ventilating, and air conditioning (HVAC) standards of the FRRP. A model for radon entry into a typical Florida house whose interior is slightly depressurized. Radon entry rates are calculatedthrough the slab and for various slablwall gaps. The effects of varying soil conditions are also examined. ................................. ........................................................ .,............................................ Preliminary methodology to develop a model-backed experimental protocol for a research house study. This experimental protocol is intended to identify and quantify the relative importance of radon entry pathways, radon movement ....................................................................................................................................... I TitleIAuthor (s) I Document Number i Description I within a house and to evaluate the effectiveness of radon measures for house construction. .....,......"................. ................-......."..........."..................................................".............. .."."........................................."I,...resistant ".................................................................................................. "."...........-""........ Guidance For Research House Studies of The Florida Radon EPA-600/R-92-191b :A description of a preliminary methodology to develop a " Research Program-Volume 2: Model-Backed Experimental Protocol For Determining Radon Resistance of Buildings. T.A. Reddy, K.Gadsby, A. Cavallo model-backed experimental protocols for identifying and ;quantifying the relative importance of radon entry pathways, I and evaluating the effectivenessof certain radon resistant measures for house construction. ............................................................. ........................ ........................ -..... .... ....*... ........................................ " Recommended Performance Standard of The Florida Radon Research Program. EPA-600/R-92-198 "S ..". One of a series of five reports recommending building construction standards. This report compares long and short term measurement results and recommends acceptable levels foi various types of measurements. Additional indoor radon data from 80 Florida houses is included in this update to a previous ! reoort. S. E. McDonough and A.D. Williamson Radon Mitigation Studies: South Central Florida Demonstration. EPA-600JR-92-207 Evaluates sub-slab depressurization system (SSD) installations I In 14 slab-on-grade house InPolk County, Florida; for optimal C.S. Fowler, et al. Idesign criteria to recommend cost-effective mitigation in house: built over comoacted soil fills. Reference Manual For RASSMIT Version 2.1 - Sub-Slab Depressurization System Design Performance Simulation Program. 1 A manual for a DOS-compatible computer program for sub-slat EPA-600R-93-027 I D.E. Hintenlang ...... ............- ................... "-â Proceedings of The Indoor Radon Modeling Workshop Florida Radon Research Program. EPA-6001R-93-052 D E. Hintenlang .................................................................... ........................-.-.......................................". ..........-..*..........*...." Recommended Foundation Barrier Construction Standard of The Florida Radon Research Program. R Eggink, E. Gazetas, D. Steuemagel, A. Scott depressurization systems design and simulation, RASSMIT version 2.1. It uses finite difference numerical solutions to simulate pressure field extension associated with discrete pits and extended suction systems particularly on slab-on-gade residential structures (air < loA-6 i..."..." ............................ ......permeability .................... ............,.. ...cmA2).. ............... EPA-600lR-93-091 -- I Experts in various aspects of modeling evaluate models relating to radon in Florida buildings in this 1991 workshop. Guidance on the use of modeling as an aid to the development of building resistant buildings .............codes .... for radon .....-..--... .................... ...."....*is presented. ........................................--.........., " . . . P i 1 One of a series of five reports recommending building construction standards developed by the FRRP. This volume recommends foundation barrier construction standards of the FRRP. It includes: concrete mix,slab design, construction I practices, opening and joint sealing, and sealant materials. ...-.-.. ...................."...--....-................... "........ ""..............."....................................... ".............................. ............. - - 1996 International Radon Symposium IP - 1.6 I I TitleIAuthor (s) Document Number K.K. Nielson, V.C.R0gers.R.B. Holt ; ....... .--..-...... "...".......................................".. ...................................................... "4." Description indoor radon entry and accumulation from data that is more mmmonly available. The model is developed from empirical inalysis of building construction and performance measurements and a theoretical sensitivity analysis from the RAETRAD model. I I 1 Soil Radon Potential Mapping of Twelve Counties In North- 28. ICentral Florida. K.K. Nielson, R.B. Holt, V.C. Rogers 1 Air InfiltrationMeasurements Using Tracer Gases: A Literature 29. I Review. ........... a........................"."".........'........."...................................................................... -...., " 30. i Feasibility of Characterizing Concealed Openings in the House- Soil Interface for Modeling Radon Gas Entry. K.K. Nielson and V.C. Rogers ..... -...-,....-..-..-..............- ..........."....*.................................-................."........... 2" 1 Radon Generation and Transport In Aged Concrete. 'I V. C. Rogers, K.K. Nielson, RB. Holt. 3 1. 3 ........... I 32. 1 Lumped- Parameter Model Analyses of Data from the 1992New ............. - House Evaluation Project Florida Radon Research Program. K.K. Nielson, R B. Holt, V.C.Rogers -...... 33. "4" ...................-- ... ......................-.. ............................. .............."............. .... 1 Laboratory Assessment of the Permeability and Diffusion I Characteristics of Florida Concretes: Phase 11. Field Samples and Analysis. i Provides separate radon potential maps plotted for the median 75%, 90%, and 95% confidence limits for twelve counties in North-Central Florida. The maps are designed to show areas that have different levels of radon potential based on soil and geographical ....... .. features. ..................................................................... ...................Provides review and comparison of tracer gases that have been used for the measurement of air infiltration into structures and interzonal flows within a structure. Tracer gases included but are not limited to sulfur hexafluoride, carbon dioxide, and arson. Anexamination of the feasibility of characterizing the total effective size of openings in the house-soil interface using a lumped-parameter model, based on the RAETRAD model for radon entry. .......... ........................................................."..........".....-. fl P . . . . . M . . . . . . . . . . . . . . . . " Results of a characterization study of radon generation and transport in concrete samples collected from 12 to 45 years old residential slabs in Florida. Compares measurement results of the old samples with newly poured concrete in Florida residential.. A further analysis of radon-resistant construction features and data from the New House Evaluation Project. This analysis was aimed at characterizingthe radon resistance of the house-soil interface for different foundation designs and comparing the feat&. effectiveness passive .-.........of.-.active and .................................................. .................................... An analysis of Florida concrete samples to determine permeability and diffusivity. Correlations of permeability and diffusivityto site added water, sand and stone mix, and fly ash content were evaluated. ....."......."....... "............... ................................"....................................................... - 1996 International Radon Symposium IP 1.8 - 1996 International Radon Symposium IP 1.9 TitleIAuthor (s) Document Number Description - - - - -- ( radon concentration. ..Provides a candidate building materials radium standard and a summary of the technical basis for the standard. The standard limits the total radium concentration 10 pW1 for any materials used in concrete and to 5 pCi/1 for concrete used in the construction of habitable structures. rechnical Basis For A Candidate Building Materials Radium Standard. /.C. Rogers and K.K. Nielson development of A Radon Protection Map For Large Buildings In EPA400/R-96-028 :lorida. K.K. Nielson, RB. Holt, V.C. Rogers - -.....'.. . Effectiveness of Radon Control Features In New House Construction South Central Florida. - Presents a radon protection map for Florida large buildings. The map shows the areas that require different levels of radon protection from soil and geographical features. The map was proposed as a basis for implementing radon-resistant building construction standards in areas of high radon risk and avoiding unnecessary regulation in areas of low ......... .~--"......"---.-.. ....radon .........risk. ............ EPA-600/R-96-044 C.S. Fowler, S.E. McDonough, A.D. Williamson .......,.Site-Specific Protocol For Measuring Soil Radon Potentials For Florida Houses. K.K. Nielson, V.C. Rogers, RB. Holt Evaluates the effectiveness of monolithic and slab-in-wall slab types in 14houses built in accordance with the Florida proposed radon-resistant construction standards in south central Florida. Sites were selected with a minimum soil gas concentration of 1,000 pCi/1. Slab integrity was monitored over time. and postcon&ction measurements were made..."in all houses. ....... Presents a protocol to provide a basis to guide measurement and interpretation of radon-related features in a particular site of existing residential radon protection maps. Site conditions that differ from the general ones used in developing the map may be used to correct for radon potential above the mapped -. category. -