Radon

1. Radon Ray Copes, Emily Peterson, JinHee Kim, Rena Chung Environmental and Occupational Health

2. Outline Radon Overview What is PHO doing? Testing/mitigation Discussion: What can we do for you? Resources 2

3. What is Radon? Decay product of uranium Colourless, odourless gas Short lived progeny release ionizing radiation during radioactive decay Radon is a decay product of uranium It is a colourless, odourless gas The short lived progeny of radon release ionizing radiation during radioactive decay Radon is a decay product of uranium It is a colourless, odourless gas The short lived progeny of radon release ionizing radiation during radioactive decay

4. Sources of Radon Exposure Rocks and soil Major source Water Small contribution Building material Small contribution Generally low levels in outdoor spaces but can accumulate in enclosed spaces The major source of radon exposures come from rocks and soil. It can enter building through cracks and openings in the walls and floor. For example it can enter through a drain pipe in the basement Water has been investigated as a source of radon exposure because in some areas, groundwater can have high levels of radon. This can then be released as a gaseous state in places such as the shower. It has been found that water only contributes a small amount to overall radon exposures Building material such as granite counter tops have also been a source of radon exposures. Again for most people these materials will not contribute significantly to their radon exposures Generally low levels in outdoor spaces but can accumulate in enclosed spaces The major source of radon exposures come from rocks and soil. It can enter building through cracks and openings in the walls and floor. For example it can enter through a drain pipe in the basement Water has been investigated as a source of radon exposure because in some areas, groundwater can have high levels of radon. This can then be released as a gaseous state in places such as the shower. It has been found that water only contributes a small amount to overall radon exposures Building material such as granite counter tops have also been a source of radon exposures. Again for most people these materials will not contribute significantly to their radon exposures

5. How Does Radon Enter Buildings? Enters building from soil air through cracks and openings Pressure differentials between soil and indoor air drive transport Radon levels increase with decreasing ventilation Can accumulate in enclosed spaces 5

6. Exposure and Dose Radon concentrations are expressed as Bq/m3 A becquerel (Bq) is the quantity of a radionuclide where one atom is transformed per second (i.e. one decay per second) Radon progeny are alpha emitters Alpha particles will usually not penetrate a sheet of paper or skin Alpha particles present a hazard when taken into the body where they can be absorbed Millisievert (mSv) is a measurement of dose Calculated by the product of Bq/m3, a conversion factor and the average time that a dwelling is occupied 6

7. Health Effects Primary exposure through inhalation Linked to lung cancer IARC group 1: Carcinogenic to humans No threshold for effect found Risk can depend on level of exposure, duration of exposure and smoking habits The major exposure pathway for radon is inhalation. Radon can get lodged in the lung once it is inhaled and it can decay and release radiation in the lung. Some people have questioned the impact of ingested radon on the GI tract but this does not appear to be a significant exposures pathway. Radon does not appear to penetrate the skin so absorption is not a concern. The major health effect from radon is lung cancer This was first shown in cohort studies of uranium miners who were exposed to extremely high levels of radon. A pooled analysis of some of these studies performed in 1995 found a RR of 1.49. (Lubin et al, 1995) Recently case-control studies done in residential studies have begun to show a small association between radon and lung cancer. Pooled studies show an association between lung cancer and radon exposures at residential levels (OR 1.11) (Krewski et al., 2005) The ability of radon to have mutagenesis effects has been shown in multiple animal and cell studies (Al-Zoughoo et al, 2009) Radon has been classified by IARC as a group 1 carcinogen The effects seen in these studies appear to be linear and so far no threshold of effect has been found As with many things the risk of lung cancer can depend on the levels of exposure and the duration of exposure but it can also depend on ones smoking habits The major exposure pathway for radon is inhalation. Radon can get lodged in the lung once it is inhaled and it can decay and release radiation in the lung. Some people have questioned the impact of ingested radon on the GI tract but this does not appear to be a significant exposures pathway. Radon does not appear to penetrate the skin so absorption is not a concern. The major health effect from radon is lung cancer This was first shown in cohort studies of uranium miners who were exposed to extremely high levels of radon. A pooled analysis of some of these studies performed in 1995 found a RR of 1.49. (Lubin et al, 1995) Recently case-control studies done in residential studies have begun to show a small association between radon and lung cancer. Pooled studies show an association between lung cancer and radon exposures at residential levels (OR 1.11) (Krewski et al., 2005) The ability of radon to have mutagenesis effects has been shown in multiple animal and cell studies (Al-Zoughoo et al, 2009) Radon has been classified by IARC as a group 1 carcinogen The effects seen in these studies appear to be linear and so far no threshold of effect has been found As with many things the risk of lung cancer can depend on the levels of exposure and the duration of exposure but it can also depend on ones smoking habits

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9. Current Guidelines Since 2007, Health Canada indoor air guideline is 200 Bq/m3 Previous guideline was 800 Bq/m3 Guideline applies to homes and public buildings with high occupancy rates Schools, hospitals, long-term care residences, correctional facilities Health Canada recommends that: When average annual radon concentrations exceed 200Bq/m3 in a normal occupancy area of a dwelling remedial action should be taken The higher the concentration the sooner the remedial measures should be taken When remedial action is taken, the radon levels should be reduced to a level as low as practicable The construction of new dwellings should employ techniques that will minimize radon entry and facilitated post-construction radon removal A �dwelling� refers to homes and public buildings with a high occupancy rate by members of the public such as schools, hospitals, long-term care residences, correctional facilities One Becquerel (Beck-a-rel)is described as one radioactive disintegration per second Year 1 results: Preliminarily results that may change with year 2 data Estimated that 7.4% of Canadian homes have elevated radon levels above 200bq/m3 7.4% of homes sampled in Ontario had radon levels above 200bq/m3 Health Canada recommends that: When average annual radon concentrations exceed 200Bq/m3 in a normal occupancy area of a dwelling remedial action should be taken The higher the concentration the sooner the remedial measures should be taken When remedial action is taken, the radon levels should be reduced to a level as low as practicable The construction of new dwellings should employ techniques that will minimize radon entry and facilitated post-construction radon removal A �dwelling� refers to homes and public buildings with a high occupancy rate by members of the public such as schools, hospitals, long-term care residences, correctional facilities One Becquerel (Beck-a-rel)is described as one radioactive disintegration per second Year 1 results: Preliminarily results that may change with year 2 data Estimated that 7.4% of Canadian homes have elevated radon levels above 200bq/m3 7.4% of homes sampled in Ontario had radon levels above 200bq/m3

10. How Risky is Radon? 10

11. 11 Smokers Indoor exposure at 800 Bq/m3: 30/100 Indoor exposure at 200 Bq/m3: 17/100 No exposure to radon (i.e., at outdoor levels): 12/100 Nonsmokers Indoor exposure at 800 Bq/m3: 5/100 Indoor exposure at 200 Bq/m3: 2/100 No exposure to radon: 1/100 Risk of Lung Cancer for Smokers and Nonsmokers, for Lifetime Exposure

12. How protective is the Radon guideline? Conventional �one-in-a-million� definition of acceptable risk used by environmental health regulators: 1/1,000,000 Current radon guideline is 1,000-10,000 times higher Excess cancer risk for lifetime consumption of water with arsenic at the minimum acceptable concentration (10 �g/L): 3 to 39/100,000 12 The implied cancer risk for lifetime exposure at the current radon guideline is 1000-10000 times higher than the cancer risk that is targeted by most environmental regulators when setting limits for carcinogens in drinking water and air Occupational health and safety regulators usually target a higher acceptable risk than environmental regulators but below the risk associated with the radon guideline The implied cancer risk for lifetime exposure at the current radon guideline is 1000-10000 times higher than the cancer risk that is targeted by most environmental regulators when setting limits for carcinogens in drinking water and air Occupational health and safety regulators usually target a higher acceptable risk than environmental regulators but below the risk associated with the radon guideline

13. How much Illness is attributable to Radon? Radon is second only to tobacco as a preventable cause of lung cancer It has been estimated that 5-14% of lung cancers in Canada attributable to radon A Canadian study estimated an attributable risk of 7.8% In 2007: 7,872 Ontarians diagnosed with lung cancer Using low end estimate of 5% attributable to radon: 393 radon attributable Lung Cancers every year Attributable risks: BC - ~5% (394) Brand et al (Canada) � 7.8% (614) BEIR VI � 10-14% (787-1102) Attributable risks: BC - ~5% (394) Brand et al (Canada) � 7.8% (614) BEIR VI � 10-14% (787-1102)

14. 14 Cross-Canada Survey of Radon Concentrations in Homes 2-year project to gather long-term (3-month or longer) indoor radon measurements Hoping to recruit approximately 18,00 participants who are recruited through phone Cross-Canada Survey of Radon Concentrations in Homes 2-year project to gather long-term (3-month or longer) indoor radon measurements Hoping to recruit approximately 18,00 participants who are recruited through phone

15. Is Radon a problem in my Health Unit? Year 1 data shows that 86% of health units in Ontario had at least one sample above 200 Bq/m3 Year 2 data may be higher The only way to know is to test Currently little literature to suggest that building factors or geology can reliably predict radon levels Health Canada recommends that all homes be tested for radon 15 Health Canada suggests that the only way to know if Radon levels are high within a building is to test that building We cannot predict where radon levels will be high in Ontario Very little evidence to suggest that certain building types will be at higher risk for radon then others At the time, we cannot predict radon levels based on home age, building type, etc.] Hunter N. et al (2009) Uncertainties in Radon related to House-specific factors and proximity to geological boundaries in EnglandHealth Canada suggests that the only way to know if Radon levels are high within a building is to test that building We cannot predict where radon levels will be high in Ontario Very little evidence to suggest that certain building types will be at higher risk for radon then others At the time, we cannot predict radon levels based on home age, building type, etc.] Hunter N. et al (2009) Uncertainties in Radon related to House-specific factors and proximity to geological boundaries in England

16. PHO Plan: Burden of Illness in Ontario Health Canada�s 2-year survey of house-level residential radon data requested Estimating burden of illness in Ontario using exposure data: 16

17. Testing Radon levels can vary by season Usually higher in winter due to decreased ventilation. As well, heated indoor air increases the pressure differential with the soil Winter testing recommended Radon levels can vary over time Long-term testing (3-12 months) best reflects average levels Radon levels tend to be higher in lower levels of home Health Canada suggests testing in lowest level of home occupied by an individual for more than 4 hours a day 17 Radon levels tend to be higher in the winter season than the summer. For these reasons Health Canada recommends that testing be conducted in the winter months when the home is closed up Radon levels can also very over time, therefore long term testing for 3 or more months is recommended Radon levels also tend to be higher in the lower levels of the home so Health Canada recommends that testing occur in the lowest level of a home that is occupied by individuals for more than 4 hours a dayRadon levels tend to be higher in the winter season than the summer. For these reasons Health Canada recommends that testing be conducted in the winter months when the home is closed up Radon levels can also very over time, therefore long term testing for 3 or more months is recommended Radon levels also tend to be higher in the lower levels of the home so Health Canada recommends that testing occur in the lowest level of a home that is occupied by individuals for more than 4 hours a day

18. Short Term vs Long Term Testing Long-Term Testing devices (preferred) Alpha-track detector Electret ion chamber Continuous radon monitor � often used by contractors Short-Term Testing devices Activated charcoal canister Alpha-track detector Electret ion chamber Continuous radon monitor 18 Charcoal canister and charcoal liquid scintillation devices absorb radon or its products on to the charcoal. The radioactive particles emitted from the charcoal are counted in the lab. Alpha track detectors have a plastic film that gets etched by the alpha particles that strike it. In the lab, the tracks are counted. Electret ion detectors have a statically charged disc in a chamber. Ions generated from radon decay strike the disc, reducing the electrical charge. The voltage reduction is measured in the lab. All except continuous monitor must be sent to an outside lab for analysis Charcoal canister and charcoal liquid scintillation devices absorb radon or its products on to the charcoal. The radioactive particles emitted from the charcoal are counted in the lab. Alpha track detectors have a plastic film that gets etched by the alpha particles that strike it. In the lab, the tracks are counted. Electret ion detectors have a statically charged disc in a chamber. Ions generated from radon decay strike the disc, reducing the electrical charge. The voltage reduction is measured in the lab. All except continuous monitor must be sent to an outside lab for analysis

19. Availability of Testing Do-It-Yourself ($30-60) Alpha-track detectors At most hardware stores, Wal-Mart, some HUs and through internet Send to lab for results Professional testing ($150-400) 19 Professional testing sites (Google �professional radon testing ontario�) mr-radon.ca ($175 for electret ion test; $400 for granite counter top test) www.environmentalservicesgroup.ca/radon.php www.pinchin.com Etc. Some with NEHA or NRPP certification http://www.neha-nrpp.org/Canada_Measurement.html http://www.neha-nrpp.org/Canada_Mitigation.html Professional testing sites (Google �professional radon testing ontario�) mr-radon.ca ($175 for electret ion test; $400 for granite counter top test) www.environmentalservicesgroup.ca/radon.php www.pinchin.com Etc. Some with NEHA or NRPP certification http://www.neha-nrpp.org/Canada_Measurement.html http://www.neha-nrpp.org/Canada_Mitigation.html

20. Mitigation Methods include Ventilation (natural and mechanical) and air pressurization Seal cracks: foundation, walls, pipes, drains Active soil depressurization Chosen method will depend on radon concentration and building characteristics Mitigation steps Feasibility test Implementing mitigation Post installation testing 20 Multiple mitigation methods are available The method that is chosen will depend on the reduction in radon concentrations that is needed and also building characteristics (foundation type, natural ventilation levels) It is important that a mitigation plan is developed along with feasibility testing before it is done. In addition after mitigation has been finished poste instillation testing is needed to ensure that it is effective Henschel, 1994 Ventilation has variable effect on indoor radon concentrations � when effective 75-90% reduction have been reported Sealing entry routes associated with 0-50% reductions in indoor radon Active soil depressurization can reduce indoor radon levels by 80-99% Has a continuing operation cost due to fan maintenance and operationMultiple mitigation methods are available The method that is chosen will depend on the reduction in radon concentrations that is needed and also building characteristics (foundation type, natural ventilation levels) It is important that a mitigation plan is developed along with feasibility testing before it is done. In addition after mitigation has been finished poste instillation testing is needed to ensure that it is effective Henschel, 1994 Ventilation has variable effect on indoor radon concentrations � when effective 75-90% reduction have been reported Sealing entry routes associated with 0-50% reductions in indoor radon Active soil depressurization can reduce indoor radon levels by 80-99% Has a continuing operation cost due to fan maintenance and operation

21. Mitigation Active-soil depressurization ($1500-3000) Most common and effective method Pipe installed in soil beneath the home to collect radon, attached fan vents the radon outdoors Pipe installation at home construction is more cost-effective 21

22. Possible Public Health Responses Health Unit education/awareness campaigns Health Canada education materials available for free upon request Building codes National model construction codes Incentives for homeowners to test and remediate Rebate if provide testing results to HU Testing and remediation in public buildings (schools) 22 Education campaigns may increase public knowledge, but do not necessarily lead to testing or remediation. Education materials are available from health Canada Building Codes New dwellings should employ techniques that will minimize radon entry and will facilitate post-construction radon removal The federal government has included Radon prevention strategies in their National model construction codes Includes air barriers and a rough-in for a possible future subfloor depressurization system Other provinces have incorporated these suggestions into the building codes (Manitoba, BC) UK study suggests that new building codes for radon are a cost-effective approach (Gray et al., 2009) Will reduce radon exposures at a population level, but may affect homes that are not affected by high radon levels Homeowner subsidy Some countries have implemented financial incentives for radon testing and remediation in the form of tax credits or rebates. May be able to increase testing and remediation uptake in existing homes Study suggests that need for increased testing and remediation uptake to make radon testing in mitigation in older homes cost effective (Gray et al., 2009. Gagnon et al . 2008) Testing and remediation in public buildings Many provinces have done some testing and remediation in public buildings (Nova Scotia, PEI, BC) Health Canada has been testing federal buildings Study from Quebec suggest that radon screening in public buildings is the most promising screening policy for reducing radon related lung cancers (Gagnon et al. 2008Education campaigns may increase public knowledge, but do not necessarily lead to testing or remediation. Education materials are available from health Canada Building Codes New dwellings should employ techniques that will minimize radon entry and will facilitate post-construction radon removal The federal government has included Radon prevention strategies in their National model construction codes Includes air barriers and a rough-in for a possible future subfloor depressurization system Other provinces have incorporated these suggestions into the building codes (Manitoba, BC) UK study suggests that new building codes for radon are a cost-effective approach (Gray et al., 2009) Will reduce radon exposures at a population level, but may affect homes that are not affected by high radon levels Homeowner subsidy Some countries have implemented financial incentives for radon testing and remediation in the form of tax credits or rebates. May be able to increase testing and remediation uptake in existing homes Study suggests that need for increased testing and remediation uptake to make radon testing in mitigation in older homes cost effective (Gray et al., 2009. Gagnon et al . 2008) Testing and remediation in public buildings Many provinces have done some testing and remediation in public buildings (Nova Scotia, PEI, BC) Health Canada has been testing federal buildings Study from Quebec suggest that radon screening in public buildings is the most promising screening policy for reducing radon related lung cancers (Gagnon et al. 2008

23. Questions for Health Units Based on what was presented in the webinar, do you need additional radon information i.e. more detailed health information, direction on sampling programs, mitigation measures, etc. Is your health unit engaged in a public education campaign? If engaged in a campaign, do you sell detection devices? Which PHO project would your health unit benefit from most: radon mapping, burden of illness calculations or both? What else can we do for you? What do health units think can be done? 23

24. Comments or questions? 24 Contact us at: Environmental and Occupational Health Team Susanne Bell (assistant to Ray Copes): 647-260-7455 eoh@oahpp.ca

25. Resources Health Canada education resources available at: http://www.hc-sc.gc.ca/ewh-semt/radiation/radon/resource-ressources-eng.php#a1 Exposure Levels Health Canada. (2010) Cross-Canada Survey of Radon Concentrations in Homes Year 1 Interim Report. http://www.chba.ca/uploads/Policy%20Archive/2010/Health%20Canada%20Radon%20Survey%2015%20Dec%202010.pdf Testing Health Canada. (2008). Guide for Radon Measurements in Residential Dwellings. http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/radiation/radon_homes-maisons/radon_homes-maisons-eng.pdf Health Canada. (2008). Guide for Radon Measurements in Public Buildings. http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/radiation/radon_building-edifices/radon_building-edifices-eng.pdf NCCEH. (2009). Residential Indoor Radon Testing. http://ncceh.ca/sites/default/files/Radon_Testing_May_2009.pdf Mitigation Health Canada. (2010). Reducing Radon levels in Existing Homes: A Canadian Guide for Professional Contractors. http://www.radonleaders.org/sites/default/files/HC%20Rn%20Mitigation%20Guide%20English_0.pdf CMHC. (2007). Radon: A guide for Canadian Homeowners. http://www.cmhc-schl.gc.ca/odpub/pdf/61945.pdf Building Codes Lehmann and Zeghal. (2011) 2010 National Model Construction Codes: Radon http://www.nationalcodes.ca/eng/presentations/Radon.pdf Ontario. (2011) Potential Changes for the next edition of the Building Code: Second Round of Consolation (February-April 2011). http://www.mah.gov.on.ca/AssetFactory.aspx?did=9064 25