Community Environmental Monitoring Program Dr. Antone L. Brooks July, 2011 Brian Head, Ut My Background • Early interest in radiation (Watching atomic weapons in Southern Utah) • MS in radiation ecology (Chasing fallout),PhD in • • radiation biology and genetics Studied health effects induced by low doses from internally deposited radio-nuclides Invested my life in research on genetic effects and cancer from low doses and dose-rate radiation (DOE Low Dose Radiation Research Program) Bad Diet Why Me?? Drinker Radiation Smoker RADIATION I am Blamed for much Human Disease • Cancer of all kinds • Mutations • Birth Defects • Heart attacks • Stroke I have even been blamed for !!! Ninja Turtles Spider Man Incredible Hulk I am natural, Radiation is everywhere Cosmic Inhaled Radon Bodies Plants Radioactive Elements Rocks We live in a sea of radiation… Normal annual exposure from natural radiation About 240 mrem/yr Radon gas Human body Rocks, soil Cosmic rays 140 mrem 40 mrem 30 mrem 30 mrem Normal annual exposure from man-made radiation About 300 mrem/yr Medical procedures Consumer products One coast to coast airplane flight Watching color TV Sleeping with another person Weapons test fallout Nuclear industry 280 mrems 10 mrems 2 mrems 1 mrem 1 mrem less that 1 mrem less than 1 mrem U.S Dose Rates from Natural Background Nevada Test Fallout Simon et al. 2006 World wide fallout in the United States Cancer Rate is Highly Variable • Race • Sex • – White 136/100,000 – Black 294/100,000 – Males 60.6% – Females 39.4% Geographic Distribution No link between high Background Radiation and Cancer – Areas with top 10 percentile of cancer= 231-892 cancers/100,000 person-years (low background) – Areas with lowest 10 percentile of cancer= 93-168 cancers/100/000 person-years (high background) What Causes Cancer? I am not a big hitter!!! Cigarette smoke Diet & nutrition Chronic infection Occupational exposure Genetic Alcohol drinking Environmental factors including radiation What Radiation Exposures Can we Modify? Man-made vs natural radiation Fallout 2% Occupational Nuclear fuel cycle 1% 2% Consumer products 16% Nuclear medicine 21% Medical x-rays 58% Man-made radiation 18% Natural background radiation 82% Beir VII What Radiation Exposures can we Modify? Man-made vs Natural Radiation Occupational Fallout 1% 1% Nuclear fuel cycle 0.5% Consumer products 6.5% Nuclear medicine/x-rays 91% Man-made radiation 52% Natural background radiation 48% Mettler 2007 Medical Radiation Exposures, YES, BUT I DO A LOT OF GOOD!!! • 200 million medical x-rays/year – X-ray 0.1 mGy • 100 million dental x-rays/year – Dental 0.06 mGy • 16 million doses of radiopharmaceuticals/yr • 80 million CT scans/year Brenner and Hall – Head scan 4-6 mGy/scan AAPM TG-204, 2011 – Body scan 30-100 mGy/scan • Large doses from radiation therapy 17 ISCORS Update Nov 2010 U.S. Department of Energy • Office of Science • Biological and Environmental Research What about the A-Bomb!! You did a lot of damage there. • • • • • Cancer Mutations Birth Defects Heart attacks Strokes Effects of the Atomic Bomb • Killed outright by the bomb or acute More than 200,000 people radiation effects. • Survived for lifespan study 86,572 people A-BOMB SURVIVOR STUDIES 5% less cancer than total controls 46,249 “Exposed” 10,159 “Controls” Pierce and Preston 2000 A-BOMB SURVIVOR STUDIES Preston et al. 2004 CONTROL AREA Excess Solid Tumors Excess Leukemias 113 28.2 116 99 64 27.7 18.9 41 10.4 44 4.7 2 479 Total 572 Total Excess Cancers 4.0 0.1 93 Total Atomic Bomb Survivor Excess Cancer Population of Survivors Studied 86,572 40% of these people are still alive 60 years after the bomb Cancer Mortality observed after the bomb 10,127 Cancers Mortality observed without the bomb 9,555 Total Cancer Mortality Excess Excess Solid + Excess Leukemia = 572 Tumor 479 94 572 Where do we get these excess cancers?? Aggregation of data on Solid Cancers • Total Solid Cancers 9555 • Stomach 2867 – Life Style, Diet, stomach bacteria • Liver 1236 – Long Latency – Influence of chronic Infections – Alcohol • Lung 1264 – Smoking – Non-linear Dose-response Preston et al. 2003 Biology of Solid Cancers • Can we really group all Solid Cancers then apply the LNT to estimate responses at low doses? – Stomach Cancer – Lung Cancer – Liver Cancer • All these cancers are known to be produced by environmental factors – Bone Cancer – Lung Cancer • These cancers have very non-linear Dose-Response Relationships – Thyroid Cancer – Prostrate, Pancreas, Uterus, Rectum??? Aggregation of Solid Cancer: Influence on Policy • Pay for the types of cancers seen to be elevated in the Abomb population. – Solid Cancers – Leukemia • Current Pay-out Cancers for Down-Winders, Nuclear Veterans, Uranium Miners – Bone, renal, leukemia, lung, multiple myeloma, bile duct, brain, breast, colon, esophagus, stomach, bladder, gal bladder, liver, ovary, pharynx, salivary gland, small intestine, thyroid, lymphoma (five years after exposure) – Current payout • • RECA = 1.3 Billion EEOICA = 3.2 Billion Interaction with Environmental factors (I get the blame!!!) • Smoking and Uranium mining • Radiation and alcohol • Radon in homes Radon in Homes (BEIR VI) • Total Cancers 157,000 Ever-Smokers Never Smokers 146,400 11,000 Radon induced Cancer Total Cancers Ever-Smokers Never Smokers (Exposure-age-Concentration model) 22,300 20,600 (Radiation only) 1,700 (Exposure-age-Duration model) 15,500 14,600 1,200 What about when you get deposited in the body?? • Inhalation and lung cancer • Low dose rate and non-uniform distribution • Deposition in target organs – – – – Strontium-90 Bone Iodine -131 Thyroid Cancer Cesium-137 Whole Body Exposure Tritium Whole Body Exposure Dose Dose-Rate Effectiveness (DDREF) Factor is it 1.0? • Dose-Dose-Rate-Effectiveness-Factor (DDREF), regulatory bodies considering making it (1.0) • Dose-rate has a marked effect at all levels of biological orgainztion • All you have to do to make DDREF 1.0 is accept a couple of low dose-rate epidemiological studies which cannot demonstrate a difference in risk for high and low dose rates • All you have to do to make a DDREF of 1.0 is to ignore 70 years of radiation biology Dose-Rate Effects at all Levels of Biological Organization • Molecular • Cellular • Tissue • Whole Organ • Cancer • Life Shortening Dose and Dose-Rate Effects DDREF derived with curve fitting of the human data. • • • DDREF 1.5 BEIR VII DDREF 2.0 ICRP (2007) DDREF 1.0 Considered by Germans DREF derived from animal and experimental data. • • • • • Experimental Molecular/Cellular Chromosome Aberrations Mouse data – Lung Adenocarcinomas – Ovarian Tumors – Thymic lymphoma – Mammary tumors – Myeloid Leukemia 4-??? 4-6 3-7 7-35 10-30 1-4 2-6 Dog Data – (Acute Death Bone Marrow) – (Acute Death Lung) Dog Data (Cancer) 3-4 10-100 15-40 Summary DDREF • • • A large dose-rate effectiveness factor is required due to the marked decrease in biological effects observed following low dose-rate radiation exposure. Current that theto mechanisms At radiation doses research less than 20suggests Gy (20,000 mGy) the lung following inhalation of radioactive materials, there is little lifedelivered shortening and a of action of these very large doses at decrease in the frequency of lung cancer. low dose-rates are different to those after acute When the dose delivered at a low dose-rate gets very, very large (80-220 low doses. Gy in Bone and 100-700 Gy in lung), the cancer frequency approaches 100%. • • • Should we consider separating DDREF from Genetic background plays an important role in the response to large total radiation doses delivered at a low dose-rate. DREF? Such data should be considered in decisions about evacuation (10-50 mSv At low dose-rates the total dose required to produce acute radiation lethality is similar to the dose required to produce a high cancer frequency. projected dose) and relocation (20 mSv projected dose first year) of the public following radiation accidents or terrorist events. Cancer in Beagle Dogs following Acute Radiation Exposure 40 % Incidence 35 30 25 20 15 10 5 0 0 800 mGy Benjamin et al 1998 Dose Response for Life Shortening Following Inhalation of 90-Strontium Fused Clay Particles 7000 6000 Days to Death 5000 Cancer Other 4000 Heart Cancer Lung Cancer 3000 2000 TBLN Cancer 1000 Acute 0 0 100 200 300 400 500 600 700 Cumulative Dose (Gy) 800 900 1000 All cancers Control dogs Control dogs Lung cancer Total Cancer and Lung Cancer 75 70 Percent of Dogs with Cancer 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 5 10 15 Total dose to lung (Gy) 20 25 % Total Cancer (Controls) by Location 100 90 80 70 60 % Cancer 50 40 38.3 46.4 47.3 47.6 32.6 38.2 27.0 30 20 10 0 National Lab % Cancer STDEV % Lung Cancer (Control) by Location 10 9 8 7.2 7 6 % Cancer 4.9 5 4 % L. Cancer/Dogs 3.3 2.9 3 2 1 2.0 1.6 1.0 0 National Lab The Shape of the Dose-Response is Dependent on Control Selection (What is the Best Control?) ITRI FAP Controls 53 % Lung Cancer 15 10 ITRI FAP Controls ITRI and PNNL Controls 318 ITRI and PNNL Controls All Controls 5 ITRI Exposed All Controls 1096 0 0.00 5.00 10.00 15.00 Total Dose to Lung (Gy) 20.00 25.00 Selection of Proper Controls?? • Dog Data – Add more control dogs for greater accuracy – Adding dogs greater genetic variation – Adding dogs different environmental and life styles • Human Data – Match controls for life-style, stress and environment, Age, Sex etc. – “the distal group has about 5% higher cancer rates than estimated for zero dose from the proximal group.” (Pierce and Preston 2000) – Adding more people increases variation in genetic variation, record keeping, environment, life-style. How much is a Bq? • Scientific definition • Social definition • Risk • Will I be OK? Comparing Environmental and Health Effects (Bq?) • The levels in the environment are very nonuniform • The amount of radiation required to produce health effects is much higher than that in the environment (large safety factor) • There is a decrease in effectiveness with partial body exposures • There is a decrease in effectiveness with decreasing dose-rate. Mechanistic Studies of Low Dose Effects • • • • • • • The risk for radiation induced cancer in human populations is low and undetectable at low doses and dose-rates thus mechanistic studies are required. DOE Low Dose Radiation Research Program http://www.lowdose.energy.gov Cells can detect and respond to very low doses of ionizing radiation Radiation responses at all levels of biological organization are different at high doses than at low doses. High dose-rate produces more biological damage than low dose-rate exposures Bystander effects, adaptive responses, ROS status of the cells, and genomic instability are interrelated and can be related to protective mechanisms. This resulted in major paradigm shifts in Radiation biology. Thus, mechanisms of radiation action change as a function of dose and dose-rate. Data suggest that radiation exposures are detrimental at high doses and protective at low doses. Mechanistic studies of Low Dose Effects • • • • • • • Cells can detect and respond to very low doses of ionizing radiation Radiation responses at all levels of biological organization are different at high doses than at low doses Thus, mechanisms of radiation action change as a function of dose. Data suggest that they are detrimental at high doses and protective at low doses. Low Dose research require paradigm shifts in radiation biology to support the data. Bystander effects, adaptive responses, ROS status of the cells, and genomic instability are interrelated and can be related to protective mechanisms. The risk for radiation induced cancer in human populations is low and undetectable at low doses and dose-rates. Linear low dose (LNT) extrapolation is not supported by low dose radiation research Helpful Reviews of Health Effects from Low dose and dose-rate radiation • Health Physics 97: November 2009, Special Issue: 44th Annual Meeting of the National Council on Radiation Protection and Measurements: Low Dose and Low Dose-Rate Radiation Effects and Models. • Dauer, LT, Brooks, AL, Hoel, D, Morgan W, Stram D, Tran P. (2010) Evaluation of updated research on the health effects associated with lowdose ionizing radiation, Radiation Protection Dosimetry 140 (2) 103-136. • Health Physics 100:, March 2011, Special Issue: Proceedings of the Conference on Biological Consequences and Health Risks of Low-Level Exposure to Ionizing Radiation: In honor of Victor P. Bond. Radiation Risk: What Is the Public Perception? • Radiation is very bad • There is good and bad radiation, (Medical and Environmental) • Each and every ionization increases their risk for cancer (LNT) • Many conclude that if you are exposed to radiation you are going to get cancer • If you were exposed to radiation and you get cancer the radiation caused the cancer It is not all my Fault!! At low doses I do way more good than harm!!!