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Radon Review and Update:How Good is the Science

Mar 2010

EPA Office of Radiation and Indoor Air (ORIA)Indoor Environments Division (IED)

CAPT Susan Conrath, PhD, MPH,US Public Health Service

conrath.susan@epa.gov 202-343-9389

Radon as an Indoor Problem

• When:

• Where:

• How:

Radon as an Indoor Problem

• When: 1984

• Where:

• How:

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Radon as an Indoor Problem

• When: 1984

• Where: Limerick Nuclear Power PlantReading Prong area of PA

• How:

Radon as an Indoor Problem

• When: 1984

• Where: Limerick Nuclear Power PlantReading Prong area of PA

• How: Stanley Watras set off plantnuclear alarms

Radon as an Indoor Problem

• When: 1984

• Where: Limerick Nuclear Power PlantReading Prong area of PA

• How: Stanley Watras set off plantnuclear alarms

Radon was coming from his home[2700 pCi/L]

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Stanley Watras Family & Home

Policy Setting Considerations

Policy Setting Considerations

• Scientific Basis

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Policy Setting Considerations

• Scientific Basis

• Best Available technology

Policy Setting Considerations

• Scientific Basis

• Best Available technology

• Cost-Benefit

Policy Setting Considerations

• Scientific Basis

• Best Available technology

• Cost-Benefit

• Legislation

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EPA & Radon

EPA has general Regulatory Authority to implement Title III of TSCA (i.e. IRA).

Voluntary ProgramRadon Outreach Effort

EPA relies on others for Research/Science Development

Radon Risk in Perspective

• EPA and its Science Advisory Board– Radon among the top four

Environmental risks to the Public• Harvard Risk in Perspective, 1998,

John Graham– Radon ranked #1 risk in the Home

Radon Risk

• Second Leading cause of Lung Cancer

• Leading cause of Lung Cancer in Non-Smokers

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Source of Radon Risk

Alpha Radiation

Epidemiology Study Designs• Cohort

Epidemiology Study Designs• Cohort

– Identify populations based on exposure– Follow for disease occurrence

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Epidemiology Study Designs• Cohort

– Identify populations based on exposure– Follow for disease occurrence

• Ecological

Epidemiology Study Designs• Cohort

– Identify populations based on exposure– Follow for disease occurrence

• Ecological– Compares level of disease & exposure in

groups– Cannot correlate exposure to sick individuals– Cannot control for confounders

Epidemiology Study Designs• Cohort

– Identify populations based on exposure– Follow for disease occurrence

• Ecological– Compares level of disease & exposure in groups– Cannot correlate exposure to sick individuals– Cannot control for confounders

• Case-Control

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Epidemiology Study Designs• Cohort

– Identify populations based on exposure– Follow for disease occurrence

• Ecological– Compares level of disease & exposure in groups– Cannot correlate exposure to sick individuals– Cannot control for confounders

• Case-Control– Identify Individuals with disease & individuals without disease– Look at and compare exposures

EPA’s Risk Assessments Based on Miner [Occupational] Studies

Radon Risks Are Significant and Supported By Strong Science

• National Academy of Science [NAS] BEIR VI Report - The Health Effects of Exposure to Indoor Radon

(February, 1998)

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BEIR VI Conclusions

BEIR VI Conclusions

• Serious public health problem

BEIR VI Conclusions

• Serious public health problem • Second-leading cause of lung cancer

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BEIR VI Conclusions

• Serious public health problem • Second-leading cause of lung cancer• No evidence of a threshold

BEIR VI Conclusions

• Serious public health problem • Second-leading cause of lung cancer• No evidence of a threshold• Effects of Radon & Smoking more

powerful in combination

BEIR VI Conclusions

• Serious public health problem • Second-leading cause of lung cancer• No evidence of a threshold• Effects of Radon & Smoking more

powerful in combination• Radon contributed to 15,000 or 22,000 US

lung cancer deaths in 1995 [2,100 or 2,900 in never smokers].

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BEIR VI Conclusions• Serious public health problem • Second-leading cause of lung cancer• No evidence of a threshold• Effects of Radon & Smoking more powerful in

combination• Radon contributed to 15,000 or 22,000 US lung

cancer deaths in 1995 [2,100 or 2,900 in never smokers].

• Reduction of Residential Radon levels above 4 pCi/L could prevent approx. 1/3 of the annual deaths

Summary of Miner StudiesCourtesy J. Lubin (NCI)

• Clear lung cancer dose-response in all cohort studies

Summary of Miner StudiesCourtesy J. Lubin (NCI)

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• Clear lung cancer dose-response in all cohort studies

• BEIR VI miner-based risk models (11 studies)

Summary of Miner StudiesCourtesy J. Lubin (NCI)

• Clear lung cancer dose-response in all cohort studies

• BEIR VI miner-based risk models (11 studies)

• Continuing expansion of data (currently 15 studies)

5,000+ cases, 2M person-yrs

Summary of Miner StudiesCourtesy J. Lubin (NCI)

• Clear lung cancer dose-response in all cohort studies

• BEIR VI miner-based risk models (11 studies)

• Continuing expansion of data (currently 15 studies)

5,000+ cases, 2M person-yrs

• Cumulative exposures in miners overlap home

exposures

Summary of Miner StudiesCourtesy J. Lubin (NCI)

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Cohort Studies (15) of Radon-Exposed MinersCourtesy J. Lubin (NCI)

Radium Hill

Czech Republic (2)

China

Ontario

Port Radium

Beaverlodge

NewfoundlandFrance

New Mexico

Sweden

Colorado

Cornwall E Germany

Brazil

EPA Assessment of Risks from Radon in Homes, by ORIA/Radiation Protection Division

(EPA 402-R-03-003, June 2003)

EPA Radon Assessment Results

– Modified & extended the NAS BEIR VI report [consultation with SAB and NAS panel members]

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EPA Radon Assessment Results

– Modified & extended the NAS BEIR VI report [consultation with SAB and NAS panel members]

– Best estimate of US population risk in homes is about 20,000 (21,100) lung cancer deaths per year. [At US average indoor radon conc.]

EPA Radon Assessment Results

– Modified & extended the NAS BEIR VI report [consultation with SAB and NAS panel members]

– Best estimate of US population risk in homes is about 20,000 (21,100) lung cancer deaths per year. [At US average indoor radon conc.]

– Current Risks at Action Level• Smokers 6/100• Never Smokers 7/1000

EPA Action Level

• 4 pCi/L• Technology-based NOT Health-based• Lower Levels are NOT Safe• Risks @ Action Level

– Smokers 6/100 [10-2]– Never Smokers 7/1000 [10-3]

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Scope of the Radon Risk in Homes

Scope of the Radon Risk in Homes

• 100M ‘should test’ homes

Scope of the Radon Risk in Homes

• 100M ‘should test’ homes

• 6% (1:15) of homes > 4 pCi/L

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Scope of the Radon Risk in Homes

• 100M ‘should test’ homes

• 6% (1:15) of homes > 4 pCi/L

• As of 2008, 7.1M US homes still have elevated indoor radon levels

Strengths of Radon Risk Assessment

Strengths of Radon Risk Assessment

• Known Human Carcinogen

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Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies

Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk

Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk• Extensive Review by National and

International Groups

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Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk• Extensive Review by National and

International Groups• Consensus of Expert Committees

Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk• Extensive Review by National and

International Groups• Consensus of Expert Committees• ID as Serious Public Health Risk

Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data

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Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data• Well Characterized Exposure of General

Population

Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data• Well Characterized Exposure of General

Population• Analysis of Dosimetry in Mines & Homes

Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data• Well Characterized Exposure of General

Population• Analysis of Dosimetry in Mines & Homes• Extrapolation NOT Large

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Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data• Well Characterized Exposure of General

Population• Analysis of Dosimetry in Mines & Homes• Extrapolation NOT Large• Extensive Peer Review & Detailed

Uncertainty Analysis

Additional Strengths of Radon Risk Assessment

• Risk Model Derived from Human Data• Well Characterized Exposure of General

Population• Analysis of Dosimetry in Mines & Homes• Extrapolation NOT Large• Extensive Peer Review & Detailed

Uncertainty Analysis• International Consensus on Risk

Miner to Residential Extrapolation

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Equivalent?

Radon Residential Case-Control Studies

• 22 worldwide residential case-control studies [19 show an assoc]

• Small study populations

US Department of Energy [DOE] & Commission of European

Communities [CEC] Residential Pooling Workshops

(1989,1991, 1995)

• Continuing meetings of PIs after 1995

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Residential Case-Control PoolingEuropean Pooling

• 13 Studies from 9 Countries– Austria– Czech Republic– Finland [nationwide]– Finland [south]– France– Germany [eastern]– Germany [western]– Italy– Spain– Sweden [nationwide]– Sweden [never smokers]– Sweden [Stockholm]– United Kingdom

• Total 7,148 cases and 14,208 controls

North American Pooling

• 7 Studies from 2 countries:– New Jersey– Winnipeg– Missouri I [non-smoking women]– Missouri II [women]– Iowa– Connecticut– Utah-South Idaho

• Total 3,622 cases and 4,966 controls

Chinese Pooling

• 2 Studies– Gansu– Shenyang

• Total 1050 cases and 1996 controls

North American, European and Chinese Residential Risk Pooling

Studies

• Provide direct evidence

• Results:– Validate miner extrapolations– Directly demonstrate residential radon risks

N. America EuropeChina Miner Studies

OR = 1

EPAAction Level

4 pCi/L

Radon Concentration, pCi/L

Results of All Radon Studies of Lung CancerCourtesy of Jay Lubin, NCI

Odd

s R

atio

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Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk• Extensive Review by National and International Groups• Consensus of Expert Committees• ID as Serious Public Health Risk• Risk Model Derived from Human Data• Well Characterized Exposure of General Population• Analysis of Dosimetry in Mines & Homes• Extrapolation NOT Large• Extensive Peer Review & Detailed Uncertainty Analysis• International Consensus on Risk

Strengths of Radon Risk Assessment

• Known Human Carcinogen• Extensive Epidemiological Studies• Consistency in Magnitude of Risk• Extensive Review by National and International Groups• Consensus of Expert Committees• ID as Serious Public Health Risk• Risk Model Derived from Human Data• Well Characterized Exposure of General Population• Analysis of Dosimetry in Mines & Homes• Extrapolation NOT Large• Extensive Peer Review & Detailed Uncertainty Analysis• International Consensus on Risk• New Residential Pooling Results

US Radiation Exposure

• Radon Largest Source of Radiation Exposure [Exclud. Med]

• Outdoor Radon Natural Pollutant

• Radon in Homes is NOT

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Comparative US Cancer Death Rates in 2005

Courtesy of Bill Field (U of Iowa)

C o m p a rin g R a d o n R e la te d C o m p a rin g R a d o n R e la te d C an ce r to O th e r C a n ce r T y p e sC an ce r to O th e r C a n ce r T y p es

02 0 0 04 0 0 06 0 0 08 0 0 0

1 0 0 0 01 2 0 0 01 4 0 0 01 6 0 0 01 8 0 0 02 0 0 0 0

Ann

ual U

.S. C

ance

r Dea

ths

L u n g C a n c e r (ra d o n )

L iv e r C a n c e r

B ra in C a n c e r

S to m a c h C a n c e r

M e la n o m a

O ra l C a n c e r

G a llb la d d e r C a n c e r

B o n e C a n c e r

US Surgeon General’s National Health Advisory on

RadonIssued January 13, 2005

• "Indoor radon is the second-leading cause of lung cancer in the United States”

• “breathing it over prolonged periods can present a significant health risk”

• "Radon can be”– “detected with a simple test”– “fixed through well-established venting techniques"

Public Service CampaignU.S. Surgeon General

TV, Print (Magazine, Newspaper), Radio

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WHO International RN Project[IRP]

WHO IRP• Started in 2005

WHO IRP• Started in 2005• Key output: WHO Handbook on Indoor

Radon [launched Sept 2009]

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WHO IRP• Started in 2005• Key output: WHO Handbook on Indoor

Radon [launched Sept 2009]• 30 countries and over 100 experts

WHO IRP• Started in 2005• Key output: WHO Handbook on Indoor

Radon [launched Sept 2009]• 30 countries and over 100 experts• Consensus: indoor radon is a leading

cause of lung cancer world wide

WHO IRP• Started in 2005• Key output: WHO Handbook on Indoor

Radon [launched Sept 2009]• 30 countries and over 100 experts• Consensus: indoor radon is a leading

cause of lung cancer world wide• First Global Call-to-Action on indoor RN

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WHO Handbook on Indoor Radon

WHO Handbook on Indoor Radon

• Consensus document

WHO Handbook on Indoor Radon

• Consensus document• Almost complete agreement with US

positions

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WHO Handbook on Indoor Radon

• Consensus document• Almost complete agreement with US

positions• Recommended a reference level of 2.7

pCi/L

New Reference Level Will Not Affect EPA’s Action Level of 4 pCi/L

New Reference Level Will Not Affect EPA’s Action Level of 4 pCi/L

• EPA’s recommends:Consider fixing homes testing 2-4 pCi/L since No Safe Level

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New Reference Level Will Not Affect EPA’s Action Level of 4 pCi/L

• EPA’s recommends:Consider fixing homes testing 2-4 pCi/L since No Safe Level

• WHO Handbook recommends countries reduce reference level only afterimproving their testing and fixing rates

Why Not Just Expand Non-Smoking Programs

Why Not Just Expand Non-Smoking Programs

• Radon is a communal not an individual risk

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Why Not Just Expand Non-Smoking Programs

• Radon is a communal not an individual risk

• US has had 50+ years of non-smoking programs

Why Not Just Expand Non-Smoking Programs

• Radon is a communal not an individual risk

• US has had 50+ years of non-smoking programs

• Most US households don’t allow smoking

Why Not Just Expand Non-Smoking Programs

• Radon is a communal not an individual risk

• US has had 50+ years of non-smoking programs

• Most US households don’t allow smoking• Need to address the source of the Radon

exposure

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Other Recent Developments

• Presidents Cancer Panel invited speakers on radon to its Dec 2008 Environmental Cancer Meeting.– Interim Reports released in Dec 2009 & Jan 2010– Final Report in April 2010

Other Recent Developments

• Presidents Cancer Panel invited speakers on radon to its Dec 2008 Environmental Cancer Meeting.– Interim Reports released in Dec 2009 & Jan 2010– Final Report in April 2010

• Health Physics Society came out with a new Position Paper on radon– Released in Oct 2009– Endorses EPA’s Action Level of 4 pCi/L– Endorses EPA Rec. to consider fixing between 2 and

4 pCi/L

Rn Program has accomplished a lot…

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More than 6,000 Lives Saved

We still have much to do…

EPA Policy Position on Radon

• Because Radon:- Constitutes Substantial Risk- Is Largely Preventable- Is Easy to Control

• Reduction of Risk from Radon Exposure is Prudent Public Policy