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Community Environmental Monitoring Program Dr. Antone L. Brooks July, 2011Brian Head, Ut Slide 2 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) Slide 3 Radiation Bad Diet Drinker Smoker Why Me?? Slide 4 RADIATION I am Blamed for much Human Disease Cancer of all kinds Mutations Birth Defects Heart attacks Stroke Slide 5 I have even been blamed for !!! Spider Man Ninja Turtles Incredible Hulk Slide 6 I am natural, Radiation is everywhere We live in a sea of radiation Cosmic Inhaled Radon Rocks Radioactive Elements Plants Bodies Slide 7 About 300 mrem/yr Medical procedures 280 mrems Consumer products 10 mrems One coast to coast airplane flight 2 mrems Watching color TV 1 mrem Sleeping with another person 1 mrem Weapons test fallout less that 1 mrem Nuclear industry less than 1 mrem Normal annual exposure from man-made radiation Normal annual exposure from natural radiation About 240 mrem/yr Radon gas 140 mrem Human body 40 mrem Rocks, soil 30 mrem Cosmic rays 30 mrem Slide 8 U.S Dose Rates from Natural Background Slide 9 Nevada Test Fallout Simon et al. 2006 Slide 10 World wide fallout in the United States Slide 11 Slide 12 Cancer Rate is Highly Variable Race White 136/100,000 Black 294/100,000 Sex 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) Slide 13 What Causes Cancer? I am not a big hitter!!! Slide 14 What Radiation Exposures Can we Modify? Slide 15 What Radiation Exposures can we Modify? Slide 16 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 Head scan 4-6 mGy/scan Body scan 30-100 mGy/scan Large doses from radiation therapy Brenner and Hall AAPM TG-204, 2011 Slide 17 U.S. Department of Energy Office of Science Biological and Environmental Research 17 ISCORS Update Nov 2010 Slide 18 What about the A-Bomb!! You did a lot of damage there. Cancer Mutations Birth Defects Heart attacks Strokes Slide 19 Effects of the Atomic Bomb Killed outright by the bomb or acute radiation effects. Survived for lifespan study More than 200,000 people 86,572 people Slide 20 10,159 Controls 3 Km (2 mSv) 46,249 Exposed 2.45 Km (5 mSv) Pierce and Preston 2000 5 Km 5% less cancer than total controls A-BOMB SURVIVOR STUDIES Slide 21 3 Km 1 Km 2. Km 64 113 116 99 41 44 2 28.2 27.7 18.9 10.4 4.7 4.0 0.1 93 Total 479 Total 572 Total Excess Cancers Solid Tumors CONTROL AREA Leukemias Excess Preston et al. 2004 Slide 22 Atomic Bomb Survivor Excess Cancer Total Cancer Mortality Excess 572 Population of Survivors Studied 86,572 Cancer Mortality observed after the bomb 10,127 Cancers Mortality observed without the bomb 9,555 Excess Leukemia 94 Excess Solid Tumor 479 572+= 40% of these people are still alive 60 years after the bomb Slide 23 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 Slide 24 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??? Slide 25 Aggregation of Solid Cancer: Influence on Policy Pay for the types of cancers seen to be elevated in the A- bomb 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 Slide 26 Interaction with Environmental factors (I get the blame!!!) Smoking and Uranium mining Radiation and alcohol Radon in homes Slide 27 Radon in Homes (BEIR VI) Total Cancers Ever-Smokers Never Smokers 157,000 146,400 11,000 Radon induced Cancer Total Cancers Ever-Smokers Never Smokers (Exposure-age-Concentration model) (Radiation only) 22,300 20,600 1,700 (Exposure-age-Duration model) 15,500 14,600 1,200 Slide 28 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 Slide 29 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 Slide 30 Dose-Rate Effects at all Levels of Biological Organization Molecular Cellular Tissue Whole Organ Cancer Life Shortening Slide 31 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 4-??? Chromosome Aberrations 4-6 Mouse data Lung Adenocarcinomas 3-7 Ovarian Tumors 7-35 Thymic lymphoma 10-30 Mammary tumors 1-4 Myeloid Leukemia 2-6 Dog Data (Acute Death Bone Marrow) 3-4 (Acute Death Lung) 10-100 Dog Data (Cancer) 15-40 Slide 32 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. At radiation doses less than 20 Gy (20,000 mGy) to the lung following inhalation of radioactive materials, there is little life shortening and a decrease in the frequency of lung cancer. When the dose delivered at a low dose-rate gets very, very large (80-220 Gy in Bone and 100-700 Gy in lung), the cancer frequency approaches 100%. 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. Genetic background plays an important role in the response to large total radiation doses delivered at a low dose-rate. Such data should be considered in decisions about evacuation (10-50 mSv projected dose) and relocation (20 mSv projected dose first year) of the public following radiation accidents or terrorist events. Should we consider separating DDREF from DREF? Current research suggests that the mechanisms of action of these very large doses delivered at low dose-rates are different to those after acute low doses. Slide 33 Benjamin et al 1998 Cancer in Beagle Dogs following Acute Radiation Exposure Slide 34 Dose Response for Life Shortening Following Inhalation of 90-Strontium Fused Clay Particles Acute Cancer Lung Cancer Other Heart Cancer TBLN Cancer Slide 35 Total Cancer and Lung Cancer Total dose to lung (Gy) 0 5 10 15 20 25 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Percent of Dogs with Cancer Lung cancerControl dogs All cancersControl dogs Slide 36 % Total Cancer (Controls) by Location Slide 37 % Lung Cancer (Control) by Location Slide 38 ITRI Exposed LNT FIT Slide 39 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. Slide 40 How much is a Bq? Scientific definition Social definition Risk Will I be OK? Slide 41 Slide 42 Slide 43 Slide 44 Comparing Environmental and Health Effects (Bq?) The levels in the environment are very non- uniform 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. Slide 45 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.govhttp://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 Slide 46 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 Mechanistic studies of Low Dose Effects Slide 47 Helpful Reviews of Health Effects from Low dose and dose-rate radiation Health Physics 97: November 2009, Special Issue: 44 th 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 low- dose 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. Slide 48 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 Slide 49 It is not all my Fault!! At low doses I do way more good than harm!!!