Radon in Florida: Current Status

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1 Radon in Florida: Current Status Clark Eldredge, M.S. Bureau of Environmental Health Florida Department of Health (DOH) April 1, /1/2016 1

2 Current Status The current understanding of radon risk and exposure in Florida is most influenced by legislative actions in the late 1980s and mid 1990s, radon distribution research in the early 1990 s and exposure to dose estimates of the late 1990 s and early 2000 s. 3/1/2016 2

3 Current Status Continued Health standard setting agencies are still evaluating the latest exposure to risk estimates of the late 2000s and early 2010s. There are recent federal efforts to revitalize action on radon. 3/1/2016 3

4 Topics To Be Covered State laws and regulations Federal risk reduction efforts Public/private Initiatives Florida data Risk estimates and standards 3/1/2016 4

5 Florida Statutes Chapter : (1) Environmental Standards (2) Certification (3) Public Information (4) Mandatory Testing (5) Notification on Real Estate Documents 3/1/2016 5

6 Federal Efforts Indoor Radon Abatement Act, 1988 Federal Radon Action Plan, 2011 National Radon Action Plan, /1/2016 6

7 Indoor Radon Abatement Act Ongoing federally funded: State grants Informational documents Ongoing non-federally funded: Model construction standards Regional training centers 3/1/2016 7

8 Indoor Radon Abatement Act Continued Completed, discontinued or transitioned: Technical assistance Study of schools Proficiency programs Federal building study 3/1/2016 8

9 Federal Radon Action Plan , federal agencies adopted strategies to reduce radon risk 33 specific actions identified Biggest impact action testing and mitigation in multi-family housing 3/1/2016 9

10 Federal Radon Action Plan Partners 3/1/

11 National Radon Action Plan Released November 2015 Expand partnerships to include non-profit and private sector Ultimate goal: Incorporate radon testing, radon mitigation and radon-resistant construction into the systems that govern purchasing, financing, constructing and renovating homes and other buildings. 3/1/

12 National Radon Action Plan Partners American Lung Association American Association of Radon Scientists and Technologists American Society of Home Inspectors Cancer Survivors Against Radon Children s Environmental Health Network Conference of Radiation Control Program Director Citizens for Radioactive Radon Reduction Environmental Law Institute U.S. Environmental Protection Agency U.S. Department of Health and Human Services U.S. Department of Housing and Urban Development National Center for Healthy Housing 3/1/

13 Radon Risk Leading cause of lung cancer in nonsmokers Contributor to lung cancer in smokers 21,000 annual lung cancer deaths 3/1/

14 Alpha Emitter High linear energy transfer radiation (LET IR) Resulting damage to DNA is clustered together Significant incidence of double strand breaks Much more challenging to repair accurately 3/1/

15 Alpha DNA Damage Total DNA DNA breaks α α α α DNA breaks Overlay Dr. Aaron Goodarzi, University of Calgary, 3/1/

16 DNA repair kinetics for high LET IR 100 % unrepaired DNA breaks Hours after irradiation >7 days 3/1/

17 Radon Units Concentration: picocuries per Liter (pci/l) Becquerels per cubic meter (Bq m -3 ) Exposure Rate: Working Levels (WL) Becquerels hours per cubic meter (Bq h m -3 ) Exposure: Working Levels Months (WLM) 3/1/

18 Risk Estimates International Commission on Radiological Protection, System of Radiological Protection in 2007 (ICRP, 2007), Detriment-adjusted nominal risk coefficient for a population of all ages: 8x10-10 per Bq h M -3 or 5x10-4 WLM -1 3/1/

19 Risk Estimates Continued For a nominal risk coefficient of 5x10-4 WLM -1 there is an average of 1 lung cancer per 2000 WLM exposure to a population. 3/1/

20 Risk Estimates Continued For every 2000 Floridians who reduce their annual average radon concentration by 5.2 pci/l (192 Bq m -3 ) (0.5 Equilibrium ratio) or 6.4 pci/l (237 Bq m -3 ) (0.4 Equilibrium ratio), one lung cancer is avoided. 3/1/

21 Florida Data Facilities Tested 1995 to present 13,200 facilities 31,500 buildings 186,700 results Residences Tested 41,600 from 1990 to ,400 from 2000 to ,300 from 2010 to present 3/1/

22 Florida Radon Standards Florida Administrative Code Rule 64E : Normal Indoor Background: Working Levels (WL) Indoor shall not exceed : 0.02 WL US Environmental Protection Agency Action Level: 4 pci/l (148 Bq m-3) 3/1/

23 Residential Elevated Radon 1990 to % reporting Rn >= 4 pci/l, average elevated level 8.2 pci/l 2009 to % reporting Rn >= 4 pci/l, average elevated level 8.3 pci/l 2010 to % reporting Rn >= 4 pci/l, average elevated level 7.8 pci/l For all testing, 130,200 residences 24% reporting Rn >= 4 pci/l, average elevated level 8.1 pci/l 3/1/

24 Mitigation Results Average post mitigation indoor radon concentration in Florida residences is 2.0 pci/l (74 Bq m -3 ) Average mitigation reduces exposure by 6.1 pci/l (237 Bq m -3 ) or 75% 3/1/

25 Avoidable Lung Cancers In 2104, there were 19.5 million Floridians. If 24%, (4.7 million) lived with elevated radon and all homes were mitigated on January 1 st to achieve a 6.1 pci/l reduction in average radon concentration, 2,300 future lung cancers would have been avoided that year. 3/1/

26 Estimate Limitations Testing in one building or structure cannot be used to predict actual radon levels in any other structure. 24% of homes with elevated radon is only accurate when applied to the 130,000 residences in the dataset. 3/1/

27 Better Estimate 1) Exclude population in mobile homes: No data on their radon exposure exists. 2) Evaluate population exposed to radon in each county using DOH measurement data. 3) For counties without sufficient data, assign state average for applicable EPA radon zone. 4) Evaluate data for any possible adjustment factors. 3/1/

28 EPA Radon Zone Map Is a policy planning tool. Ranks counties by amount of radon risk reduction for a given amount of effort. Zone 1 has the biggest return on investment, zone 3 has the least. Florida has no zone 1 counties. 3/1/

29 Data Coverage Take 175 radon measurements as the minimum number for inclusion 29 counties, containing 90% of Florida s population, have at least 175 radon tests 9 total EPA zone 2 counties; 8 with at least 175 radon tests 58 total EPA zone 3 counties; 22 with at least 175 radon tests 3/1/

30 Percentage of Homes > 4 pci/l Population weighted average for counties with more than 175 measurements: Florida EPA zone 2 counties: 28.6% Florida EPA zone 3 counties: 14.8% 3/1/

31 Florida Housing From the American Communities Survey: 9% of all Floridians live in mobile homes Depending on the county, 1.3% to 52.1% of the dwellings are mobile homes 17.6 million of 19.5 million Floridians live in site built housing (2013) 3/1/

32 Range of Elevated Radon County # of Homes Tested % of Housing % >=4 pci/l Bay % 0% Broward 15, % 32% Collier 10, % 56% Indian River % 17% Marion 3, % 44% Saint Johns % 1% 3/1/

33 Additional Correction Leon County: Testing 383 randomly selected Leon County residences found 20% homes with elevated radon vs. 25% for the county in the DOH radon database. 3/1/

34 With Correction Estimating percentage of homes with elevated radon from raw county level data may over estimate occurrence by 20%. 3/1/

35 Revised Homes with Radon Estimated number of Florida residences with elevated radon is 2.6 million. Calculated and summed by county Adjusted down for potential over estimation 3/1/

36 Avoidable Lung Cancers If 2.6 million Floridians lived with elevated radon and all homes were mitigated on January 1 st to achieve a 6.1 pci/l reduction in annual average radon concentration, 1300 future lung cancers would have been avoided in one year. Compared to 11,700 Lung cancer deaths per year from all causes. 3/1/

37 Any Questions? 3/1/

38 Thank you for your time. Clark Eldredge, MS Radon & Indoor Air Program Public Health Toxicology Section Bureau of Environmental Health Florida Department of Health / /1/

Summary of ICRP Recommendations on Radon

ICRP ref 4836-9756-8598 January 26, 2018 Summary of ICRP Recommendations on Radon Radon is a natural part of the air we breathe. Radon levels outdoors are generally very low, but can be considerably higher