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Current National and International Scientific Radon-Related Activities and Educational Initiatives Keynote Address. R. William Field, Ph.D., M.S. Associate Professor Department of Occupational and Environmental Health Department of Epidemiology College of Public Health 104 IREH
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Current National and International Scientific Radon-Related Activities and Educational Initiatives Keynote Address R. William Field, Ph.D., M.S. Associate Professor Department of Occupational and Environmental Health Department of Epidemiology College of Public Health 104 IREH University of Iowa Iowa City, IA 52242 bill-field@uiowa.edu Fifteenth National Radon Meeting Shelter Pointe Hotel and Marina San Diego, California September 25–28, 2005
Current National and International Scientific Radon-Related Activities and Educational Initiatives • Residential Radon Epidemiology • European Residential Radon Pooling • North American Residential Radon Pooling • Global Residential Radon Pooling • Iowa and Missouri Glass-based Residential Pooling (Laboratory and Field Studies - Steck) • Genetic polymorphims • Other diseases related to radon exposure? • Educational Initiatives • Coordination of stakeholders within regions and states • World Health Organization Initiative
Radon Epidemiology 1556 Agricola - Miners in Europe 1879 Harting & Hesse - Lung Cancer in Miners 1921 Uhlig - Radium Emanations & Lung Cancer 1950s Peller - First Review of Mining Related Cancers 1970s Studies of Underground Miners (ongoing) 1990s Residential Radon Studies 1994 NCI Pooled Analyses of Miners 1999 NAS BEIR VI Report 2005 North American and European Pooled Residential Radon Studies 2007 Global Pooling of Residential Radon Studies 2007 Pooling of Glass-based Residential Radon Studies
European Residential Radon Pooling Radon in homes and risk of lung cancer: European case-control studies collaborative analysis of individual data from 13 European Case-control studies. S Darby, D Hill, A Auvinen, J M Barros-Dios, H Baysson, F Bochicchio, H Deo, R Falk, F Forastiere, M Hakama, I Heid, L Kreienbrock, M Kreuzer, F Lagarde, I Mäkeläinen, C Muirhead, W Oberaigner, G Pershagen, A Ruano-Ravina, E Ruosteenoja, A Schaffrath Rosario, M Tirmarche, L Tomácek, E Whitley, H-E Wichmann, and R Doll British Medical Journal 330: 223, Jan 2005 7,148 Cases, 14,208 controls
European Pooling Summary • The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m3 • After correction for the dilution caused by random uncertainties in measuring radon concentrations, an increase of 16% (5% to 31%) per 100 Bq/m3 was noted • Small cell histologic type most associated with radon exposure
North American Residential Radon Pooled Analyses Residential Radon and Risk of Lung Cancer: a Combined Analysis of 7 North American Case-control Studies Krewski D, Lubin JH, Zielinski JM, Alavanja M, Catalan VS,Field RW,Klotz JB, Letourneau EG, Lynch CF, Lyon JI,Sandler DP, Schoenberg JB, Steck DJ, Stolwijk JA, Weinberg C, Wilcox HB Epidemiology 16(2):137-45. Mar 2005 3,662 cases, 4,966 controls
Basement and Living Area Radon Concentrations for U.S. Residential Radon Studies. 1Summary data represent those homes that were measured with no imputed (values added to replace missing values) values.
North American Pooling Summary • The 11% estimated risk at 100 Bq/m3is consistent with the predicted excess risk of 12% per 100 Bq/m3 based on a linear model developed by the National Research Council • When the analyses were restricted to individuals living in one or two homes for at least 20 years, the risk estimates increased to 18% at 100 Bq/m3
Pooled Analyses Agreement ?? 10% – 18% New Jersey, Missouri I, Canada, Iowa, Missouri II, a combined study from Connecticut, Utah and S. Idaho Shenyang, China, Stockholm, Sweden, Swedish nationwide, Winnipeg, Canada, S. Finland, Finnish nationwide, SW England, W. Germany, Sweden, Czech Republic, Italy-Trento, Spain, Austria, France, China - Gansu Province, E. Germany 16%
We have “demonstrated that empiric models with improved retrospective radon exposure estimates were more likely to detect an association between prolonged residential radon exposure and lung cancer.” Therefore, estimated pooled risk estimates are likely low. Journal of Exposure Analysis and Environmental Epidemiology 12(3):197-203, 2002.
2.2 2.0 1.8 1.6 Odds Ratio 1.4 WLM20 1st Story 1.2 BR BR/LR LR 1.0 Basement 0.8 Risk Estimates for Alternative Models(live cases and controls) Complete exposure Other location radon concentrations only 20-39% 40-59% 60-79% 80+% JEAEE 12(3): 197-203, 2002
Special Residential Radon Publication February 2006 issue Samet, J. Residential Radon Epidemiology Zielinski, J, Field, R.W., Residential Radon and Lung Cancer - Preface Krewski et al. A Combined Analysis of North American Case-Control Studies of Residential Radon and Lung Cancer. Field et al. An Overview of the North American Case-Control Studies of Residential Radon and Lung Cancer. Sandler et al. Connecticut, Utah/S. Idaho Residential Radon Studies Steck, D., Field, R.W. Dosimetric Challenges for Residential Radon Epidemiology.
GLOBAL RESIDENTIAL RADON POOLING Led by Sarah Darby at Oxford, U.K. Next meeting of investigators – Geneva, March 2006 Anticipated completion 2007 New Jersey, Missouri I, Canada, Iowa, Missouri II, Connecticut, Utah and S. Idaho, Shenyang, China, Stockholm, Sweden, Swedish nationwide, Winnipeg, Canada, S. Finland, Finnish nationwide, SW England, W. Germany, Sweden, Czech Republic, Italy-Trento, Spain, Austria, France, China - Gansu Province, E. Germany 10,810 cases; 19,174 controls
Current Activities Current collaboration between the University of Iowa and the National Cancer Institute involve pooling of the glass-based retrospective radon detectors used in the two studies. We believe the glass-based detectors provide both improved retrospective radon and radon progeny dosimetry.
“Glass-Based” Residential Radon Studies Glass-based detectors measure embedded radon progeny in glass surfaces and can be used to reconstruct the average radon concentration for periods as long as several decades.
Radon-222 a,g Polonium-218 a,g Lead-214 b,g Bismuth-214 b,g Polonium-214 a,g Lead-210 b,g Bismuth-210 b,g Polonium-210 a,g Lead-206 (Stable) 4 day Retrospective Radon Detectors 3 min • Progeny adhere to solid objects • Can become embedded in glass • surfaces 27 min 20 min 0.2 ms 22 yrs • Alphas can be detected from Po 210 • decay. • Can provide a long-term indication of • radon decay deposition on objects in • home. • A means to look back in time at radon • levels. 5 day 138 day
Recent results for retrospective radon-related dose reconstruction from radon progeny implanted in glass Dose per unit radon Exposure room studies Simplified Models Comparison with exposure room results
Dose Conversion Factor • Concept • Improve dose rate estimate using a dose delivery efficiency factor to interpret the radon or radon progeny concentration • Basis • Small radon progeny (nanoparticles) are much more effective at delivering dose to sensitive lung tissues than either radon or progeny attached to aerosols • Different home atmospheres have different mixtures of small and large progeny
Radon Dose Conversion FactorsDose rate per unit radon concentrationmeasured in a radon exposure room
Introduction and Background • Each of these processes must be modeled for all the progeny
Model correlations • Look for strong correlations between measurable activities and dose • Non-linear or linear functions • single or multiple variables
What’s the situation in homes? • Long-term, integrated measurements of airborne radon progeny, radon, and deposited radon progeny in a variety of homes to test the model • Fieldwork started in Iowa and Minnesota with a goal of at least 20 houses, depending on funding, in each state split between smoking and non-smoking. • Extremely challenging work
Residential Radon Epidemiology: Do the risk estimates indicate that everyone has the same risk of developing radon induced lung cancer? • First degree relatives of a lung cancer victim have a 2 to 3 fold increased risk of developing lung cancer. • Genetic polymorphisms play a role in susceptibility. Genetic polymorphisms are defined as variations in DNA that are observed in 1% or more of the population.
Ionizing radiation can directly and indirectly damage DNA Free radical formation Alpha Particle Double –strand DNA breaks Defects in tumor suppressor genes – p53 At risk individuals–GSTM1 (glutathione S-transferase M1)
Bonner MR, Bennett WP, Lan Q,Wright ME, Lubin JH, Field RW, Brownson RC, Alavanja MCR,Radon, Environmental Tobacco Smoke, Glutathione-s-transferase M1 and Lung Cancer in US Women. • Recent work with collaborators at the NCI and City of Hope (Los Angeles) have explored gene-environment interactions between residential radon, environmental tobacco smoke (ETS), and the GSTM1 null genotype. • The sample series included lung cancer cases pooled from three previously completed case-control studies. • Recent results show a statistically significant 3-fold increase in the interaction OR for GSTM1 null cases compared with GSTM1 present cases. • These findings have just been submitted for publication.
Why is it so hard to get people to take action on radon ?? • Invisible, odorless, colorless • Naturally occurring (no villains) • Can not link deaths to radon exposure • Long latency period • Not a disease affecting children • Not a dread hazard • Cancers occur one at a time • Voluntary risk • Lack of press – no sensational story • No sensory reminders to repetitively stimulate us to think about it
“Motivation is the art of getting people to do what you want them to do because they want to do it.” Dwight D. Eisenhower “Motivation is a fire from within. If someone else tries to light that fire under you, chances are it will burn very briefly.” Stephen R. Covey
Education is the starting point • Lead by example – Develop a “Top 10” reasons I am concerned about radon presentation. Describe why you have a fire inside to take action on radon. • Provide sample health-based presentations to local civics groups etc. • Team up with local health organizations
Comparing Radon Related Cancer to Other Cancer Types Lung Cancer (radon) 20000 Liver Cancer 18000 16000 Brain Cancer 14000 Stomach Cancer 12000 Annual U.S. Cancer Deaths 10000 Melanoma 8000 Oral Cancer 6000 4000 Gallbladder Cancer 2000 Bone Cancer 0
NetworkingMaximize Educational Efforts • National Institute of Environmental Health Sciences, Environmental Health Sciences Research Center, University of Iowa • U.S. EPA Region VII • Iowa Department of Public Health • American Lung Association • Iowa Consortium for Comprehensive Cancer Control • Holden Comprehensive Cancer Center • Iowa Air Coalition • American Cancer Society
International Radon Initiative January 2005 Develop guidelines for member countries to reduce radon exposure and develop radon measurement and mitigation guidelines. http://www.who.int/ionizing_radiation/env/radon/en/index.html
What are the benefits of an international action agenda on radon? • Provide scientific consensus on radon health risks • Promote public awareness of health risks associated with residential radon • Promote action at national level • Increase homeowner compliance with voluntary/advisory radon guidelines • Set minimum criteria for radon risk management (e.g. measurement and mitigation) that allow for country specific needs)
WHO Jan 17-18 Geneva Consensus Statements • For many people, radon represents the largest source of exposure to ionizing radiation in humans. • Radon is known to cause lung cancer in humans. • Radon is an important contributor to the human lung cancer burden, after tobacco smoking.
Radon is considered responsible for some 10 percent of the human lung cancer burden in developed countries/worldwide (will differ between developed and undeveloped countries). • The BEIR VI Report estimated there are approximately 22,000 deaths annually from radon in the United States alone (European results will be added). • Radon related lung cancer risk is affected by tobacco smoking with most radon-related lung cancers occurring in smokers; however, radon is one of the leading causes of cancer in nonsmokers. • Radon should be a priority public health issue for national environmental and radiation safety programs.
There is a need to carefully evaluate the costs and benefits of national and international radon mitigation programs. • Based on existing knowledge of geological conditions and building types, and consideration of the total lung cancer burden, countries should consider developing cost-effective national or regional policies on testing and mitigation. • Where appropriate, countries should build capacity within the public and or/private sectors to provide testing, mitigation and radon resistant new construction. • Where appropriate, countries should issue and widely disseminate statements that address the importance of radon risk reduction and the steps that can be taken to reduce such risks.
Countries should explore ways to address radon health risks in a cost-effective manner, considering both the installation of preventive measures in new buildings and remediation of existing buildings. • National governments should team with other stakeholders to ensure radon risk communication messages are delivered from multiple sources • Governments should strive to include radon health messages and action steps with other national efforts on green buildings, housing policy and the built environment.
Radon Working Groups • Risk Assessment – “World burden of disease” • Exposure Guidelines • Measurement and Mitigation • Cost Effectiveness • Risk Communication • Program Evaluation
Measurement and Mitigation Working Group • Radon Entry and Fate • Measurement Methods and Devices • Measurement Practices, Protocols, and Standards • Quality Management, Assurance, and Control • Mitigation Methods • Mitigation Practices and Standards • Prevention Strategies and Codes • Recommended Content for Training Programs for Radon Testers and Mitigators • Gaps of Knowledge and Research Recommendations
Measurement Methods and Devices • Recommended detector needs to be able to perform well under a variety of field conditions (good accuracy and precision in the field setting) • Factors that affect validity of the measurement need to be examined (e.g. humidity, gamma radiation, thoron, etc.)
Summary • Residential radon epidemiology has made major advances the past few years. • We no longer need to rely solely on extrapolations from miners to predict risk for people exposed to residential radon. • We now have direct evidence that prolonged residential radon is one of our leading public health risks and major cause of cancer. • The challenge now is to use this information so that a fire can be lit within people to test and mitigate as well as to promote radon resistant new construction.