Presentation on theme: "Community Environmental Monitoring Program"— Presentation transcript:
1Community Environmental Monitoring Program Dr. Antone L. BrooksJuly, Brian Head, Ut
2My BackgroundEarly interest in radiation (Watching atomic weapons in Southern Utah)MS in radiation ecology (Chasing fallout),PhD in radiation biology and geneticsStudied health effects induced by low doses from internally deposited radio-nuclidesInvested my life in research on genetic effects and cancer from low doses and dose-rate radiation (DOE Low Dose Radiation Research Program)
4RADIATION I am Blamed for much Human Disease Cancer of all kindsMutationsBirth DefectsHeart attacksStroke
5I have even been blamed for !!! Ninja TurtlesSpider ManIncredible Hulk
6I am natural, Radiation is everywhere CosmicInhaled RadonBodiesPlantsRadioactive ElementsRocksWe live in a sea of radiation…
7Normal annual exposure from natural radiation About 240 mrem/yrRadon gas mremHuman body mremRocks, soil mremCosmic rays mremNormal annual exposure from man-made radiationAbout 300 mrem/yrMedical procedures mremsConsumer products mremsOne coast to coast airplane flight mremsWatching color TV mremSleeping with another person mremWeapons test fallout less that 1 mremNuclear industry less than 1 mremThis slide demonstrates that we all receive a total of about 370 mrem (0.37 mSv) of radiation exposure each year from background sources. The range of exposures from background is very high in different environments. Background radiation increases as a function of elevation, as a function of radon in homes and from natural radioactive materials in the environments. There are some areas where the natural background radiation dose is increased by more than a factor of ten. Many of the man made exposure are being regulated at levels much below background. For example there are some very vigorous discussions on whether the level for exposure from man-made sources should be 15 or 25 mrem per year. Since both of these levels are far below the background level, and the range of background level is so high, it is difficult to justify the needed expense required to comply with the lower standard.
11The high and variable background rate of cancer is illustrated in every county in the United States. This slide shows cancer rate broken down into percentiles with the highest rates shown as red and the lowest rates illustrated as blue. This interesting map illustrates that some geographical regions have very high cancer rates while other regions are low. One of the features of this map is that it illustrates that in the high elevation, high cosmic radiation western states that the cancer rate is low. The highest cancer rates seem to be along the Mississippi river where the background radiation is very low. There are so many confounding factors in the environment that the cancer rate cannot be linked to any one of them. The map helps illustrate that radiation is not one of the big hitters in the production of cancer.
12Cancer Rate is Highly Variable RaceWhite 136/100,000Black 294/100,000SexMales 60.6%Females 39.4%Geographic Distribution No link between high Background Radiation and CancerAreas with top 10 percentile of cancer= cancers/100,000 person-years (low background)Areas with lowest 10 percentile of cancer= cancers/100/000 person-years (high background)
16Medical Radiation Exposures, YES, BUT I DO A LOT OF GOOD!!! 200 million medical x-rays/yearX-ray 0.1 mGy100 million dental x-rays/yearDental 0.06 mGy16 million doses of radiopharmaceuticals/yr80 million CT scans/yearHead scan 4-6 mGy/scanBody scan mGy/scanLarge doses from radiation therapyBrenner and HallAAPM TG-204, 2011
18What about the A-Bomb!! You did a lot of damage there. CancerMutationsBirth DefectsHeart attacksStrokes
19Effects of the Atomic Bomb Killed outright by the bomb or acute radiation effects.Survived for lifespan studyMore than 200,000 people86,572 people
20A-BOMB SURVIVOR STUDIES 10,159 “Controls”3 Km (2 mSv)46,249 “Exposed”2.45 Km (5 mSv)5% less cancer than total controls5 KmPierce and Preston 2000
21A-BOMB SURVIVOR STUDIES 3 KmPreston et al. 2004CONTROL AREA2. KmExcessExcessSolid TumorsLeukemias1 Km113116994144228.227.718.910.44.74.00.164572 Total Excess Cancers479 Total93 Total
22Atomic Bomb Survivor Excess Cancer Population of Survivors Studied ,57240% of these people are still alive 60 years after the bombCancer Mortality observed after the bomb 10,127Cancers Mortality observed without the bomb ,555Total Cancer Mortality ExcessExcess Solid Tumor 479Excess Leukemia 94+=572
23Where do we get these excess cancers Where do we get these excess cancers?? Aggregation of data on Solid CancersTotal Solid Cancers 9555Stomach 2867Life Style, Diet, stomach bacteriaLiver 1236Long LatencyInfluence of chronic InfectionsAlcoholLung 1264SmokingNon-linear Dose-responsePreston et al. 2003
24Biology of Solid Cancers Can we really group all Solid Cancers then apply the LNT to estimate responses at low doses?Stomach CancerLung CancerLiver CancerAll these cancers are known to be produced by environmental factorsBone CancerThese cancers have very non-linear Dose-Response RelationshipsThyroid CancerProstrate, Pancreas, Uterus, Rectum???
25Aggregation of Solid Cancer: Influence on Policy Pay for the types of cancers seen to be elevated in the A-bomb population.Solid CancersLeukemiaCurrent Pay-out Cancers for Down-Winders, Nuclear Veterans, Uranium MinersBone, 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 payoutRECA = 1.3 BillionEEOICA = 3.2 Billion
26Interaction with Environmental factors (I get the blame!!!) Smoking and Uranium miningRadiation and alcoholRadon in homes
27Radon in Homes (BEIR VI) Total Cancers Ever-Smokers Never Smokers157, , ,000Radon induced Cancer(Exposure-age-Concentration model) (Radiation only)22, , ,700(Exposure-age-Duration model)15, , ,200
28What about when you get deposited in the body?? Inhalation and lung cancerLow dose rate and non-uniform distributionDeposition in target organsStrontium-90 BoneIodine -131 Thyroid CancerCesium-137 Whole Body ExposureTritium Whole Body Exposure
29Dose 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 orgainztionAll 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 ratesAll you have to do to make a DDREF of 1.0 is to ignore 70 years of radiation biology
30Dose-Rate Effects at all Levels of Biological Organization MolecularCellularTissueWhole OrganCancerLife Shortening
31Dose and Dose-Rate Effects DDREF derived with curve fitting of the human data.DDREF BEIR VIIDDREF ICRP (2007)DDREF 1.0 Considered by GermansDREF derived from animal and experimental data.Experimental Molecular/Cellular 4-???Chromosome Aberrations 4-6Mouse dataLung Adenocarcinomas 3-7Ovarian TumorsThymic lymphomaMammary tumors 1-4Myeloid Leukemia 2-6Dog Data(Acute Death Bone Marrow) 3-4(Acute Death Lung)Dog Data (Cancer)
32Should we consider separating DDREF from DREF? Summary DDREFA 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 ( Gy in Bone and 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.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.Should we consider separating DDREF from DREF?
33Cancer in Beagle Dogs following Acute Radiation Exposure Benjamin et al 1998
34Dose Response for Life Shortening Following Inhalation of 90-Strontium Fused Clay ParticlesCancerOtherHeart CancerLung CancerTBLN CancerAcute
35Total Cancer and Lung Cancer All cancersTotal Cancer and Lung CancerControl dogsControl dogsLung cancer75706560555045403530252015105Percent of Dogs with CancerTotal dose to lung (Gy)
39Selection of Proper Controls?? Dog DataAdd more control dogs for greater accuracyAdding dogs greater genetic variationAdding dogs different environmental and life stylesHuman DataMatch 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.
40How much is a Bq? Scientific definition Social definition Risk Will I be OK?
44Comparing Environmental and Health Effects (Bq?) The levels in the environment are very non-uniformThe 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 exposuresThere is a decrease in effectiveness with decreasing dose-rate.
45Mechanistic 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 ProgramCells can detect and respond to very low doses of ionizing radiationRadiation 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 exposuresBystander 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.
46Mechanistic studies of Low Dose Effects Cells can detect and respond to very low doses of ionizing radiationRadiation responses at all levels of biological organization are different at high doses than at low dosesThus, 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
47Helpful 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 low-dose ionizing radiation, Radiation Protection Dosimetry 140 (2)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.
48Radiation Risk: What Is the Public Perception? Radiation is very badThere 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 cancerIf you were exposed to radiation and you get cancer the radiation caused the cancer
49It is not all my Fault!!At low doses I do way more good than harm!!!