26th National Radon Training Conference September 18–21, 2016 San Diego, CA

Risks from Radon in Homes (and Costs for Its Control) What is new since BEIR VI? David Pawel, Ph.D. (EPA/RPD) Richard Krop, Ph.D. (CADMUS)

DISCLAIMER The numbers given in this presentation are preliminary and do not reflect official new EPA estimates of risk for radon in homes.

“The more that things change, the more they pretty much stay the same.”

“Current” Estimates of Risk from Radon in Homes Radon in homes: “second-leading cause of lung cancer.” Based on 1995 population data, EPA estimated that about 21K die each year from radon-induced lung cancer Average cost per life saved (EPA 1992): $1.2 million (2016 $) Current EPA estimates of radon risk (2003) are based on NAS (1999) BEIR VI models Derived from data from 11 cohorts of underground miners Risks from radon depend on baseline lung cancer rates Excess risk from radon >> for smokers than non-smokers Models applied to 1989-1991 mortality data What has happened since?

Ten to Twenty years later

Are Efforts to Control Radon Cost Effective? Several more recent publications called into question EPA’s approach to controlling radon and its effects Lantz et al. (2013) Radon, smoking and lung cancer: The need to refocus radon control policy Also Mendez (2009) on impact of declining smoking on radon-related cancer Ford et al. (1999) Radon and lung cancer : A cost-effectiveness analysis About $5 million (2016$) per life saved !!!! Based on BEIR IV (NAS 1988) Used 4% discount rate for both benefits and costs

New Information on Risk from Radon New underground miner study results East German miners (WISMUT cohort) Other study updates, e.g., Czech, French, Colorado Plateau Direct information from pooled analyses of residential case-control studies Thirteen European studies (Darby et al 2006) Seven North American studies (Krewski et al 200?) Iowa, NJ, Winnipeg, Missouri (2), Iowa, Conn., Utah/Idaho Changes in Baseline Rates Smoking prevalence has decreased

What Else Might Have Changed or is New? Costs for mitigating homes? How homes are tested ? Average radon levels ? Effectiveness of Mitigations ? Housing patterns and demographics Pennsylvania “Hot Spot” homes

Questions to Be Addressed What effect might all this new information have on projections of risk for radon in homes? What impact might it have on comparisons of estimated benefits vs. costs? What are the most important gaps in knowledge? Will NOT present new official EPA estimates of risks for radon in homes

EPA and BEIR VI Radon Risk Models and Projections

Pooled Underground Miner Data (11 Cohorts) Number of Lung Cancers 113 (Non-exposed), 2674 (Exposed) Cohorts with largest number of lung cancer cases China (980), Czech (705), Colorado (336), Ontario (291), Newfoundland (118) Mean exposure 164 WLM (miners) vs. 14 WLM (lifetime residential) Cohorts with largest number of cancers among miners exposed to < 50 WLM Ontario (180), China (77), Radium Hill (52) Mean exposure rate and duration 2.9 WL, 5.7 y Cohorts with Smoking Data China, Colorado, Newfoundland, 3 others

EPA Estimates of Risk for Radon in Homes for the U.S. Population EPA formulas for calculating risk for the U.S. population: 5.4 × 10-4 lung cancer deaths per WLM 9.7 × 10-4 (WLM)-1 (ES); 1.7 × 10-4 (WLM)-1 (NS) Average exposure of 0.18 WLM per year (@ 1.25 pCi/L) Life expectancy of about 75 y Lifetime risk = 0.7% = 5.4 × 10-4 × 0.18 × 75 (All) 1.3% = 9.7 × 10-4 × 0.18 × 74 (ES) 0.2% = 1.7 × 10-4 × 0.18 × 76 (NS) About 13% attributable to radon Of 157.3K lung cancers (2010), 21K attributable to radon

Radon Risk Projections Using Updated (2010) Mortality Statistics Increases in lung cancer death rates from radon exposure is roughly proportional to the baseline rates. New information on all cause mortality, lung cancer rates, smoking prevalence Cancer Intervention & Surveillance Modelling Network (CISNET) Applied current EPA (BEIR VI) radon risk model to updated (2010) mortality data An estimated 51% (males) & 37% (females) will (or have) smoked. Previous estimates: 53% (M), 41% (F)

Change in Mortality Statistics Relatively Minor Impact on “BEIR VI” Model Projections General Population Ever Smokers Never Smokers Risk per 104 WLM 4.2 5.4 7.8 9.7 1.4 1.7 Lifetime Risk @ 4 pCi/L 1.9% 2.3% 3.4% 4.1% 0.6% 0.7% Etiologic Fraction 12% 13% 11% 20% 26% # Attributable to Radon per year 18K (2010) 21K (1995) 18K (1995) 3K (1995) 90% UI for 1995 8K-45K

How Many Deaths are Avoided from Mitigations in the U.S.? Proportional to avg. radon level reduction from mitigations Depends on radon levels in target populations Depends on the testing “protocol” Effectiveness of mitigations Assume radon levels can be reduced to 2 pCi/L Alternative assumptions could be made “Our” estimate of average reduction = 3.3 pCi/L Out of 100K homes that are targeted (267K people): 6.3K mitigations; 16.7K people affected; (IF) mitigations last 25y Deaths Avoided (one estimate!) = 82 = 16.7K × (3.3 × 25y × 0.144 WLM/y) × 4.2×10-4 WLM-1

BUT When Would the Deaths Have Occurred?

Deaths Avoided Due to Mitigations (3 Deaths Avoided Due to Mitigations (3.3 pCi/L reduction for 25 or 75y; million people)

How Should Benefits Be Counted? Lung cancers avoided would otherwise occur 5 to >100 years after radon levels are reduced EPA/NCEE recommends discounting benefits (at 3%). Decisions on discounting have a huge impact on benefit/cost results.

Discounting of Deaths Avoided When economic analysis are conducted using discounting, a death avoided that would have occurred today counts more than a death avoided that would occur later. At a 3% discount rate: the number of avoided deaths that would otherwise occur 30y from now are divided by the factor = 1.0330=2.4 (or multiplied by about 41%). Suppose the “value of a statistical life” is $8.8 million. Value of a life “saved” 30 y from now = 0.41*$8.8 M = $3.6 M Value of a life “saved” 50 y from now = 0.23*$8.8 M = $2.0 M Value of life “saved” 50 y from now @4% = 0.14*$8.8 M = $1.2M

Deaths Avoided After Discounting (100K Homes Targeted) Discount Rate Effective for 25 y Effective for 70 y None 82 231 1% 54 123 3% 26 44 4% 19 29 5% 14 20

Projections Based on Alternative Radon Risk Models New underground miner study results East German miners (WISMUT cohort) Other study updates, e.g., Czech, French, Colorado Plateau Direct information from pooled analyses of residential case-control studies Thirteen European studies (Darby et al 2006) RR models: increase in lung cancer death rates from radon exposure is roughly proportional to baseline rates Applied radon risk models derived for these alternate sources to updated (2010) mortality data

Underground Miner Studies WISMUT (Bismuth) East German Wismut uranium mines supplied the Soviet Union atomic industry from 1946. Uranium from occupied Germany > amount from Soviet Union (Walsh et al. 2014) The largest study of health risks associated with exposures to underground miners About 59K members in cohort About 3K lung cancer cases: About equal to the total in the pooled analysis of underground miners for BEIR VI . An estimated 1.4K attributable to radon (Walsh et al. 2010) Large size allows for estimates of how risk depends on factors such as age, exposure rate, time-since-exposure

WISMUT (Limitations) Incomplete smoking information Nested case-control study (Schnelzer et al 2009) About 700 cases; 1.4K controls High proportion of smokers: Cases (95%); Controls (75%) Estimates of excess risk for exposure to radon did not depend greatly on whether smoking is taken into account. Other exposures: diesel fumes, asbestos Ascertainment of cause of death < 60% before 1970 Estimates based on pre-1970 vs. post-1970 data are similar Most miner exposure rates >> exposure rates in homes

Pooled Analysis of European Residential Case-Control Studies Darby et al (2006) reported results from a joint analysis of 13 European residential case-control studies Provided a “direct” estimate of risk for radon in homes and “firm evidence that residential radon acts as a cause of lung cancer in home.” (p = 0.0002) Large, influential, impressive scientific achievement A total of 7K persons with lung cancer (cases) and 14K controls.

Pooled Analysis of European Residential Case-Control Studies (II) Studies carefully chosen according to the criteria Clear rules for selection of cases Controls are representative of population that lung cancer cases had been drawn Detailed residential histories for at least 15 y Careful (long-term) measurement of radon gas concentrations Data on smoking and other pertinent variables Each had at least 150 cases and 150 controls A complement to underground miner studies Less precision to examine how risk depends on age and time-since-exposure

Projected Number of Deaths Avoided (100K homes tested; 6 Projected Number of Deaths Avoided (100K homes tested; 6.3K mitigations) Length of Mitigation Discount Rate “BEIR VI” WISMUT (cohort) Europe pooled resident’l New Official EPA 25 y 0% 82 45 46 ? 3% 26 15 18 70 y 231 125 128 44 24 31

Benefits of Mitigation Deaths Avoided About $8.8M value of life saved Medical Care for Lung Cancer Patients About $120 K per lung cancer Other avoided costs not included Societal costs such as from lost employment

Mitigation Costs Installation of Active Soil Depressurization (ASD): $1460 Effective either 25 or 70 y. Maintenance Costs: $166 per year Operating Costs Fan Replacement Every 10 y: $383 Warning Device @ 37 y: $121 Testing Costs: $106 Assumed 80% through real estate transactions Only 20% of positive non-real estate tests result in retests Discount Rate: 3%

Benefit-Cost Analysis Mitigations Effective 25 y; 100K homes targeted BEIR VI WISMUT Europe Residential Lives Saved 82 (26) 45 (15) 46 (18) Costs (discounted) $44 M Installation $9.2 M Operating $21 M Testing $14 M Cost per Life Saved $530 K $980 K $960 K Cost per Life Saved (both discounted) $1.7 M $3.0 M $2.4 M I used a 25 year mitigation system life – I know this is conservative. I welcome your feedback. On the next slide I calculated it at 75 years.

Benefit-Cost Analysis Mitigations Effective 70 y; 100K homes targeted BEIR VI WISMUT Europe Residential Lives Saved 231 (44) 125 (24) 128 (31) Costs (discounted) $59 M Installation $9.2 M Operating $37 M Testing $14 M Cost per Life Saved $260 K $470 K $460 K Cost per Life Saved (both discounted) $1.4 M $2.4 M $1.9 M

Benefit-Cost Ratio Mitigations Discount Benefits? Mitigation Duration (y) “BEIR VI” WISMUT Europe Residential No 25 16.8 9.1 9.3 70 34.8 18.9 19.3 Yes (3%) 5.4 3.0 3.8 6.6 3.7 4.7

Radon Resistant New Construction Difficult to analyze benefits and costs without more information/data How much are radon levels reduced through passive depressurization? Where are the RRNCs, e.g., how many in Zone 1? What proportion of RRNCs are tested? How many that test positive are fitted with fans?

Information Wish List Areas where better information is needed/desired: RRNC !!! How many mitigations/RRNC are done each year? Fan data: how many are replacements vs. for new mitigations Testing How many are done through real estate transactions? What is actually done, e.g., testing devices, placement within homes? False-positive/negative rates? How effective are mitigations in reducing radon levels? How long are mitigations effective? What are the lung cancer risks from exposure to radon in homes?

Summary EPA’s current radon-in-home risk projections are based on risk models adapted from BEIR VI and 1990 mortality data Changes (from 1990 to 2010) in mortality statistics have a relatively small impact on radon risk projections. A “BEIR VI” model estimate suggests about 20K radon-induced lung cancer deaths in 2010 “New” information from residential case-control studies provides “direct” evidence that radon in homes causes lung cancer Risk projections based on models derived from recently published analyses, e.g., from data from WISMUT and the residential case-control studies tend to be within a factor of about 2 of BEIR VI model projections Decisions on discounting benefits can have a huge impact on results. Preliminary calculations indicate that benefit-cost ratios for mitigation may be about 3 or larger (even with discounting)

Acknowledgments We wish to thank Jani Palmer, Phil Jalbert, Dave Rowson, Bill Long and Angana Roy for their helpful comments, input and assistance.