Bill Field Bill Field, PhD, MS Department of Occupational and Environmental Health Department of Epidemiology

Transcription

1 Bill Field Bill Field, PhD, MS Department of Occupational and Environmental Health Department of Epidemiology

2 Overview Radon Health Effects/Epidemiology Cancer Control

3 CANCER MORTALITY 2015 CA: A Cancer Journal for Clinicians, p 5-29, JAN 2015 CANCER TYPE ESTIMATED U.S. DEATHS in Lung and Bronchus 158, Colon and Rectum 49, Breast Cancer 40, Pancreas 40, Prostate 27, Liver and Bile Duct 24, Leukemia 24, Lymphoma 20, Urinary Bladder 16, Esophagus 15, Ovary 14, Kidney and Renal Pelvis 14, Myeloma 11, Stomach 10, Melanoma - skin 9,940

4 What Is Radon 222 (radon)? Radon is a gas It is naturally occurring outdoors 3.8 days Radon Radium 1,600 years Uranium 4.5 billion years You can not see or smell it It enters buildings primarily from the soil

5 Radon Decay Products Po-218 and Po-214 deliver the majority of radiation dose to the lung. Radon-222 α,γ Polonium-218 α,γ Lead-214 β,γ Bismuth-214 β,γ Polonium-214 α,γ Lead-210 β,γ Bismuth-210 β,γ Polonium-210 α,γ Lead day 3 min 27 min 20 min 0.2 ms 22 yrs 5 day 138 day Stable

6 Why are radon decay products a health concern? Radon Decay Products Radon These particles are easily inhaled and deposited in the lungs where they can damage sensitive lung tissue. Radon

7 What Happens When Radon Decay Products Are Inhaled? Double Strand Breaks Highly radioactive particles adhere to lung tissue, where they can irradiate sensitive cells. Radiation can alter the cells, increasing the potential for cancer.

8 Ionizing radiation can directly and indirectly damage DNA Alpha Particle At risk individuals GSTM 1 (glutathione S-transferase M1)

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10 From NCRP Report No. 160, Ionizing Radiation Exposure of the Population of the United States (2009)

11 Epidemiology Study Designs Retrospective Cohort Study (e.g., Miner studies) Identify cohort based on exposure Follow for disease occurrence Case-Control Study (Residential Studies) Identify Individuals with disease & individuals without disease Compare exposures for cases and controls

12 Cohort Studies (15) of Radon-Exposed Miners Port Radium Ontario Beaverlodge Cornwall Newfoundland E. Germany Sweden France Czech Republic (2) China Colorado New Mexico Brazil Radium Hill

13 Radon Measurement Concentration Bq/m 3 pci/l Exposure (25y) WLM EPA Action Level WHO Guidance U.S. homes (mean) decay/sec/m

14 Radon Exposure of Lung Cancer Cases in Miners 600 Reside <20 pci/l Number of lung cancer cases <10 pci/l <5 pci/l < Working Level Months

15 3 China 8 Czechoslovakia Dose- Response in Miner Studies (I) Relative risk Colorado (<3.2K WLM) Ontario Cumulative WLM Lubin et al NRC BEIR VI, 1999

16 Dose- Response in Miner Studies (II) Relative risk Newfoundland New Mexico Sweden Beaverlodge Cumulative WLM

17 Dose- Response in Miner Studies (III) Relative risk Port Radium France Radium Hill Cumulative WLM

18 National Academy of Sciences BEIR VI 1999 Risk estimates based primarily on radonexposed miners Estimated 18,600 lung cancer deaths each year in the U.S. from residential radon exposure

19 National Research Council Conclusions Serious public health problem Second-leading cause of lung cancer No evidence of a threshold Effects of Radon & Smoking more powerful in combination Reduction of residential radon levels above 4 pci/l could prevent approx. 1/3 of the annual deaths

20 0.15 AR = 0.14 AR for Radon Attributable risk Radon in U.S. ~ 1/3 of lung cancers from homes above EPA action level (or 5-8K lung cancer deaths/yr) EPA action level Radon concentration, pci/l

21 In 2003, the EPA updated the BEIR VI risk estimates to 21,000 radon-related lung cancer deaths each year in the United States. Based on its analysis, EPA estimates that out of a total of 157,400 lung cancer deaths nationally in 1995, 21,100 (13.4%) were radon related.

22 EPA Radon Risk Assessment Results Modified & extended the NAS BEIR VI report Best estimate of U.S. of the population risk in homes is about 21,000 lung cancer deaths per year at the U.S. average indoor radon concentration of 1.3 pci/l. Current Risks at the EPA Action Level (4 pci/l) Smokers 6/100 Never Smokers 7/1000

23 EPA Radon Risk Assessment Results Modified & extended the NAS BEIR VI report Best estimate of U.S. of the population risk in homes is about 21,000 lung cancer deaths per year at the U.S. average indoor radon concentration of 1.3 pci/l. Estimated Risks at the EPA Action Level (4 pci/l) Smokers 6/100 Never Smokers 7/1000

24 CANCER MORTALITY 2015 CA: A Cancer Journal for Clinicians, p 5-29, JAN 2015 CANCER TYPE ESTIMATED U.S. DEATHS in Lung and Bronchus 158, Colon and Rectum 49, Breast Cancer 40, Pancreas 40, Prostate 27, Liver and Bile Duct 24, Leukemia 24,450 Radon- Induced Lung Cancer 21, Lymphoma 20, Urinary Bladder 16, Esophagus 15, Ovary 14, Kidney and Renal Pelvis 14, Myeloma 11, Stomach 10,720

25 Residential Radon Case-Control European Studies 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 Around the World North American Studies 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

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27 Residential Radon Case- Control Studies Odds Ratios at 4.0 pci/l Study Utah/South Idaho Connecticut Iowa Missouri-II Missouri-I Winnipeg New Jersey Shenyang Gansu United Kingdom Stockholm Sweden (never-smkrs) Sweden Spain Italy Germany (western) Germany (eastern) France Finland (south) Finland Czech Republic Austria Cases/Cntls 511/ / / / / / / / / / / / / / / / / / / / / /188 North America 4155/5341 China 1053/1997 Europe7148/ OR at 4.0 pci/l OR at 148 Bq/m 3

28 European Pooled Residential Radon Case-Control Studies Austria Czech Republic Finland [nationwide] Finland [south] France Germany [eastern] Germany [western] Italy Spain Sweden [nationwide] Sweden Sweden [Stockholm] United Kingdom 10% 18% increased lung cancer risk at 3 pci/l

29 North American Pooled Residential Radon Case-Control Studies New Jersey Winnipeg Missouri I Missouri II Iowa Connecticut Utah-South Idaho 16% increased lung cancer risk at 3 pci/l

30 Results of All Radon Studies of Lung Cancer Odds ratio Odds ratio EPA NA pooled RRs Gansu Shenyang China pooled RRs Pooled European RRs IA CT MO-1 Pooled miners UT MO-2 Winn NJ Radon concentration (x), pci/l

31 Risk Estimates for Alternative Models Iowa Radon Lung Cancer Study (live cases and controls) Odds Ratio Complete exposure WLM20 1st Story BR BR/LR LR Basement 20-39% 40-59% 60-79% 80+% Other location radon concentrations only JEAEE 12(3): , 2002

32 The International Radon Project WHO - IRP Website 2005 "Recent findings from case-control studies on lung cancer and exposure to radon in homes completed in many countries allow for substantial improvement in risk estimates and for further consolidation of knowledge by pooling data from these studies." " The consistency of the findings from the latest pooled analyses of case-control studies from Europe and North America as well as China provides a strong argument for an international initiative to reduce indoor radon risks."

33 Set radon reference level of 2.7 pci/l, as guidance, for member countries

34 Field R.W. (2011). Radon: An Overview of Health Effects. Encyclopedia of Environmental Health, Elsevier.

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36 Protracted Radon Exposure and Other Adverse Health Effects? Chronic Obstructive Pulmonary Disease (COPD) Leukemia Basal Cell Skin Cancer Cerebrovascular Disease

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38 Iowa Cancer Consortium (ICC)

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44 What can you do?

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51 Age-adjusted percent distribution of lifetime cigarette smoking status for males and females aged 65-74: United States, annualized, Current Smoker 12.6% Former Smoker 40.7% Never Smoker 46.6%

52 Age-adjusted percent distribution of lifetime cigarette smoking status for males aged 65-74: United States, annualized, Current Smoker 13% Current Smoker 13.2% Former Smoker 51.4% Never Smoker 35.4% Never Smoker 36% Former Smoker 51%

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54 The National Comprehensive Cancer Network guidelines recommend that individuals with significant occupational exposure to a lung carcinogen be offered screening beginning at age 50 years if they have a smoking history of at least 20 pack-years nccn.org/professionals/physician_gls/f_guidelines.a sp#lung_screening

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64 Summary Radon is a global public health concern. The residential radon studies have provided direct evidence that prolonged residential radon is one of our leading public health risks and major cause of cancer mortality. Radon is our leading environmental cause of cancer mortality in the United States and seventh leading cause of cancer mortality overall.

65 Contact information Bill Field, PhD, MS College of Public Health Department of Occupational and Environmental Health Department of Epidemiology University of Iowa

66 Tobacco Use and Cancer Some Cancer-Causing Chemicals in Tobacco Smoke

67 Nature May 17:249(454): Radioactivity of tobacco trichomes and insoluble cigarette smoke particles. Martell EA

68 Radon Decay Products Radon-222 α,γ Polonium-218 α,γ Lead-214 β,γ Bismuth-214 β,γ Polonium-214 α,γ Lead-210 β,γ Bismuth-210 β,γ Polonium-210 α,γ Lead day 3 min 27 min 20 min 0.2 ms 22 yrs 5 day 138 day Stable

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70 Bradford Hill causation guidelines Biological Plausibility (lung cancer smoking versus yellow index finger) Temporal relation of exposure and disease (absolute requirement) Strength of association Dose Response relationship Internal consistency within a study (age, sex, occupation) External consistency between studies Specificity of association Intervention modifies risk Analogy with other research (e.g. Toxicology)

71 "Statistics are people with the tears wiped away." Irving Selikoff