Presentation on theme: "Radiation and Radiological Events"— Presentation transcript:
1Radiation and Radiological Events John Gough, MS, CHP, CMLSORadiation Safety OfficerSwedish Medical Center
2Objectives Radiation Basics Common Radiation Sources Radiation Dose Limits and Emergency recommendationsRadiological Events as they relate to possible future eventsQ & A
3IntroductionA Radiological Event involves the accidental or purposeful release of radiation or radioactive materials into the public or environmentThis can create fear, injury and death and lead to severe disruption.Fear is due to the public’s general fear of radiation.Injury and death may be the result of the explosive and could result from sufficient radiation exposure.Disruption results from of panic and the cleanup of the radioactive material and any consequent avoidance of the radioactive location after clean up.
9Radiation Reality Been studied for over 100 years Is naturally occurringCharacterized very wellRisk are well known for high levelsHave a lot of human dataWeak carcinogenWeak mutagenSaves thousands of livesRadiation was discovered in 1895 by Wilhelm Roentgen and radioactivity a few month later by Henri Becquerel. The first diagnostic use of the new tool was in early 1896, shortly followed by uses for therapy. Today, we know more about radiation than any other hazardous material, because we have used it on so many people at varying levels. The risk is low, but have been demonstrated by the Nagasaki and Hiroshima survivors at high levels of dose.What we know now is that the main risk from low level radiation is a slight increase in the risk for cancer. The National Academy of Science, Biological Effects of Ionizing Radiation committee V estimates that for every 100,000 mrem of dose, the increase in cancer rates goes up 5%. The normal x-ray technician gets roughly 250 mrem per year – which then numerically equates to a 0.015% increase is risk. Nurses, visitors and other workers would have a much lower risk than that.
11Radiation PhysicsQuick review of some basic radiation physics
12RadiationThe most basic definition of radiation is the transfer of energy from on location to another. For example a car hitting a tree.Radiation is defined as energy in transit as either electromagnetic wave or energetic particles.In very simple terms it is the transfer of energy from one location to another.
13Ionizing vs. Non-Ionizing Non-Ionizing RadiationTransfers energy by heat conductionNo chemical effectsWith regard to electromagnetic radiation, the entirety of the EM spectrum is radiation, however there is a “gray” dividing line between x-ray and ultraviolet, with ultraviolet and lower designed as non-ionizing and x-rays and higher designated as ionizing.Ionizing RadiationHas the ability to induce chemical changesTransfers very little energy relative to biological damage
14Types and Properties of Radiation In addition of electromagnetic phenomena, radiation can also be in the form of particles (alpha, essentially a helium nuclei, beta, an energetic electron, neutrons, a elementary particle from the nucleus of an atom, and others). Graphical representation of the penetrating power of different radiations.
15Units Roentgen (R) Rad or Gray Rem or Sieverts Curie (Ci) Difference between radiation and radioactivity. If radioactivity is a pile of manure, then radiation is the smell from the pile of manure. The closer you get the stronger the smell, the further away the weaker. If you go far away there is no smell and nothing to generate the smell. If you step in the manure then you are contaminated.Rem or SievertsRadioactivity (Bq) – Attributed to material and describes the number of emissions occurring in a given timeCurie (Ci)
16Radiation Production Radioactivity Continuously emitting radiation (no off switch)e.g. Tc-99m, UraniumMachine SourcesOnly emits when one.g. X-ray Machine
17Some radioactive isotopes and their half-life A measure of the amount of time for ½ of the activity to disappearGiven enough time all radioactive materials will decay to background levels.Some radioactive isotopes and their half-lifeIsotopeHalf-LifeFluorine-18110 minutesTechnetium-99m6 hoursIodine-1318 daysIridium-19274 daysCesium-13730 yearsRadium-2261600 yearsUranium-2384.5 billion yearsRadioactiveMaterial10 half-lives8 half-lives9 half-lives7 half-lives5 half-lives2 half-lives6 half-lives3 half-lives4 half-lives1 half-life
19Sources of Background Radiation Background radiation levels is close to 1 mrem per day.
20Radiation Doses – Medical Procedures Cardiac Stress Test – 730 mremChest x-ray PA – 2 mremCT – Chest / Ab / Pelvis – 1800 mremLumbar Spine Series – 180 mremBitewing Dental X-ray – 0.4 mremI-131 Thyroid CA Therapy – 22,000 mremfrom the RAdiation Dose Assessment Resource
21Typical Radiation Doses Astronaut in space for 1 month, 15,000 mremAverage US Smoker5300 mrem to the lungs630 mrem whole body doseTSA X-ray Screening Device0.1 mrem or less per scanTypical radiation doses from other activities.Round Trip – NY to LA10 mremLiving in Denver, CO vs. Seattle WA for 1 year – 25 mrem (additional cosmic radiation exposure due to altitute)
23Acute effects generally do not occur for radiation dose below 25 rem (25,000 mrem). They also do not appear when doses are delivered over a prolonged period of time.Industrial Radiography accident due to handling of a radiography sourceHair loss as a result of a CT Brain Perfusion Scan at Cedar Sinai,Fluoroscopy “burn” early 1990
24Acute Radiation Effects (Total Body Exposures) Dose (rad)Whole BodyEffectTime to Onset25-50Blood Count ChangesDays to 1 Month150Physiological EffectsHours to Days350LD 50/60 (no medical care)2 Months600LD 50/60 (medical care)2+ Months850 – 900100% fatalWeeks1000GI SyndromeDays2000CNS EffectsHours
25Chronic / Delayed Effects The Risk of cancer from exposure to radiation is well documented for exposure to radiation doses above 10 rad (single exposure, not exposure over time).The risk from single exposure below 10 rad or chronic low level exposures (e.g. occupational doses) are postulated based on statistical analysis. There are no epidemiological studies that confirm or deny the effects of single doses below 10 rad or from chronic low level exposure where the only radiation is involved.Risk data is primarily derived from studies of the survivors of Hiroshima and Nagasaki.Delayed / Chronic effect typically show after a latency period that can be from 5 years to more than 50 years.Though acute radiation risks are obvious and well established, delayed cancer risks are more difficult to determine. Estimates of cancer risk are from studies of populations exposed to radiation doses well above 10 rad resulting in mathematical models to estimate radiation dose risk. As is the case with all models this results in some uncertainty.
26Cancer Risk Cancer risk is derived from Japanese bomb survivor data Background Cancer risk in the US is approximately 42%, fatal cancer risk, 23%risk per rem = 1 in 2,000 chance of fatal cancer per rem of exposure (general population)1 in 1,000,000 risk of fatal cancer from a Chest X-rayCancer risk is the primarily long-term biological effect. Generally, radiation will only produce a small increase in risk at low levels according to existing mathematical models.Biological Effects of Ionizing Radiation (BEIR) VII Report (2006)
27Activities with a 1 in 1,000,000 risk of fatality Driving a motorcycle 2.6 milesDriving a car 80 miles.Riding a bicycle 26 milesEating 43 TBSP of peanut butter. About 1 jar.
28Risks from Everyday Activities ActivitySmoking 10 cigarettes/dayInfluenzaPlaying SoccerHit by LightningFishing and LoggingCoal MiningAgricultureFirefighterPolice OfficerConstruction IndustryFatality/year1 in 2001 in 6,0001 in 100,0001 in 10,000,0001 in 1,0001 in 3,6001 in 4,0001 in 10,000
30Radiation Dose Limits Part of Body Annual Limit (mrem) Whole Body (TEDE)5,000Organ or Extremity50,000Lens of the Eye15,000Dose to Fetus (Radiation Worker)500General Public (individual)100Annual radiation dose limits for radiation worker and the public. Based on primarily on minimizing the likelihood of cancer effects while balancing the need to “use” radiation.*WAC and 055, 10 CFR Part 20
31Federal Protective Action Guide Dose Limit(Whole Body)Emergency Action Dose Guidelines5 remAll Activities allowed (maximum whole body dose limit for occupational workers)10 remProtection of major property only25 remLifesaving or protection of large populations>25 remLifesaving or protection of large populations. Only by volunteers who understand the risks.Federal Protection Action Guides for radiological emergencies.EPA Protective Action Guides
32Federal Protective Action Guide - Revision Dose Limit(Whole Body)Emergency Action Dose Guidelines50 remLifesaving or protection of large populations – By Volunteers>50 remLifesaving or protection of large populations. Only by volunteers who understand the risks.Additionally supplement to the Protective Action Guide increasing the upper value to 50 rem.ICRP (1991), NCRP Report No. 116 and NCRP Report No. 138, DHS (2007)
33Decontamination Limits Standard Limits USNRC and NCRP (Unrestricted Access to Property) (Has also applied to personnel contamination)2000 dpm / 100 cm2 (beta/gamma) – 1 nCi200 dpm / 100 cm2 (more hazardous beta/gamma) – 0.1 nCi20 dpm / 100 cm2 (source material) – 0.01 nCi2 mR/hr (for fixed sources, no removable contamination)Limits on the level of contamination allowed for property.
34Activity Magnitudes Use or Where typically found Activity 1 pCi (10-12 Ci)Quantities found naturally in the environment1 nCiTypical Decontamination level1 uCiTypical laboratory research quantity1 mCiDiagnostic administration of radioactivity for nuclear medicine studies1 CiTherapeutic administration of radiation (cancer treatment)1000 CiSterilization (Blood irradiators)
36International Atomic Energy Agency (IAEA) International Atomic Energy Agency (IAEA)Supplementary Radiation Symbol approved in 2007.
37Radiological Accident Statistics (1945-2007) About 50 (documented) accidents in the US involving radioactive material/radiation sources.400+ worldwide33 (documented) fatalities in the US (over ½ from medical accidents)100+ worldwide230+ (documented) radiation injuries in the US.3000+ worldwide28 documented criminal acts involving the use of radioactive material/radiation to cause injury/death (6 in the US, remainder in USSR/Russia, Taiwan and London)Radiological Accident statistics from 1945 (beginning of the atomic age) to Note the reference to criminal actions. One US event took place in 1972 in Harris County TX where the individual used and irradiator source to intentionally harm a family member. The other is the “infamous” SL-1 reactor incident in 1961.
39Scrap Metal Radiation Raises Concerns in India NY Times, April 23, 2010Scrap Metal Radiation Raises Concerns in India
40April 2010 – Mayapuri, IndiaCo-60 Gamma Cell Irradiator (unused since 1985 from New Delhi University) sold as scrap metal at auction in Feb 2010.Dealer cut the Co-60 cell into 11 pieces.8 injured, 1 death
42Photograph from HMS Vengeance November 1945 Hiroshima, Japan15 kilo-ton U-235 (80% enriched) bombPopulation 385,000Immediate damage radius ~ 1 mile80,000 (est.) fatalities (most from blast injuries (about 80%) – with 70% of the remaining 20% dying within the first two months.Statistics from Hiroshima Japan.Photograph from HMS Vengeance November 1945
43Hypothetical Improvised Nuclear Device Based on “Planning Guidance for Response to a Nuclear Detonation” Homeland Security CouncilHypothetical planning is based on a 10 kT device (Same destructive magnitude as devices used in Hiroshima and Nagasaki)Blast Damage Radius of 3 miles and fallout radius of 20 milesCasualty statistics are not specifically determined in the report but values can be determined from a comparison of the effects to populations at Hiroshima and Nagasaki vs. population of the affected area.Notes from the Homeland Security Council Guide. Uses the same size device as Hiroshima / Nagasaki in the planning.
44Projected Impact of a 10 Kiloton Improvised Nuclear Device Depiction of fatalities in Seattle from a 10 KT IND. Ground Zero is the Coleman Dock. Based on Presidential Directive #8.~50,000 dead3-5 Hospitals affected (Swedish FH, CH and Harborview, Group Health Central and Virginia Mason)Infrastructure damage out to 1 mile450,000 evacuatedContamination ~3,000 sq miles$100+ billion in costs
46Tokai-Mura – Criticality Accident Timeline of the criticality accident in Tokai-Mura Japan. The most interesting thing to note is that there was a sustained nuclear reaction for about 20 hours.
47Tokai-Mura – Criticality Accident September 30, 1999, three individuals were exposed to high radiation doses (1700, 800 and 300 rem) respectively (2 subsequently died).Authorities instructed over 300,000 people to remain indoors (shelter-in-place) for 1 day (within 10 km of the site).150 people were evacuated.347+ individuals identified as being exposed to levels of radiation above allowed public dose limits (100 mrem)20 individuals received radiation doses between (5 and 25 rem) (workers who stopped the chain reaction)Accident statistics from the event.
48Tokai villager is scanned for radiation One of the three irradiated workersOver the next 10 days 10,000+ individuals sought radiation monitoringHospital / Emergency responder statistics. Note, the PPE used by staffA total of 76,000 individuals were monitored for surface contamination.5,700 individuals visited offices for health consultation.Tokai villager is scanned for radiation
49Tokai - Demographics Tokai village – population ~35,000 Ibaraki Perfecture (county) - ~ 3 millionNear the accident site, 5 major hospitals, 3 secondary hospitals and 1 tertiary hospital.788 medical personnel (55 MD, 220 public health nurses, 39 RN, 144 RT, 330 others) were involved in the response at 5 centers.Just an idea of how this location would compare to other locations in the US.TokyoTokai
50NOTE: Swedish Medical Center’s Radiation Safety Office also examined about ~10 individuals who where concerned their radiation exposure and were in Japan during the event.Swedish’s former RSO and Rad Safety Specialist reported that several individuals were provided radiation safety surveys at their request due to concerns of being in Japan at the time of the accident (flight crews and travelers).
51Fukishima DaiichiMarch 11, 2011 – April 14, 2011
52ChronologyMarch 11, 2011 – Magnitude 9.0 Earthquake off the coast of the Tohoku Peninsula and subsequent 12 meter high tsunami that hits the northern coast of HonshuFukishima Daiichi is a group of 6 boiling water nuclear reactors with a total capacity of over 4,500 MW(e) (roughly the capacity necessary for 350,000 homes in the US)Only 3 of the 6 plants were operating at the time of the tsunami with a 4th defueled.
53ChronologyPlants and generators were designed to withstand a 5.7 meter high tsunami (18.7 feet).The following day battery power on for the reactor cooling system failed resulting the various events that leads to the uncontrolled release of radioactivity into the environment.
54EffectsBeginning March 15, 2013, measured increases in public exposure in Japan, but not at levels that would lead to any significant change in epidemiology.
55Public Fears Radiation Residents flee Tokyo and make a run on supplies
56US Officials Don’t Understand Radiation Hazards March 15, U.S. Surgeon General Regina Benjamin is in the Bay Area touring a peninsula hospital. NBC Bay Area reporter Damian Trujillo asked her about the run on (KI) tablets and Dr. Benjamin said although she wasn’t aware of people stocking up, she did not think that would be an overreaction. She said it was right to be prepared.
571.3 pCi / m^3 of I-131 detectedWould lead to a radiation dose of 1.5 mrem if an individual were to breathe this concentration for 365 days 24 hr/day.
58Aftermath Evacuation radius of 20 km, displacing 70,000 residents About 116,000 individuals were screened for radioactivity with detectable activity found on 102 individuals (limited to clothing in all cases, no intake measurable).Food and drinking water restrictions were implement for the local area on March 19 and removed on April 2.Ongoing stigma with regards to foods / products produced in the area.17 injuries (15 from explosion/thermal injuries, 2 radiation exposures)2 radiation related burns occurred on April 24 when three workers were in unit 3. Water overflowed on their boots in the turbine room setting off their personal radiation alarms. The individuals proceeded to finish their work. Whole body doses in the range of rem is estimated. Two workers received what appears to be beta burns with estimated skin doses in the range of rem. All recovered with no apparent permanent effects.
59Radiological Dispersal Large Scale Release Example
60Radiological Dispersal Device Conventional explosive device surrounded by radioactive material.Passive distribution of radiation from a stationary source or other manual or automated dispersal.Radioactivity is generally not great enough to be of a significant hazard to personnel.Used primarily as a device to inspire panic and fear, or in the case of passive dispersal to specifically target an individual or group.The consensus isotopes that would be used are those commonly used for industrial radiography, medical therapy or sterilizationWhat is an RDD.
61Goiânia, Brazil 1987: teletherapy head stolen 50.9 TBq (1375 Ci) cesium-137 teletherapy machine left in abandoned clinicWell use the event of Goiania, Brazil to get an idea of the effects of a large scale RDD.Unit dismantled, Cs-137 source capsule ruptured causing major contaminationDose rate at 1 meter from source: 456 rad/hr
62Goiânia, Brazil Source stolen on Sept 10. Initial physiological symptoms (vomiting) on Sept 13.Initial medical assistance on Sept. 15, diagnosed as an allergic reaction to bad food.Initial admission to hospital on Sept 23, initial diagnosis tropical diseaseHospital M.D. given portion of radiation source on Sept 28.Physicist determined source to be radioactive on Sept 29.Timeline of events from this “accident”.
63Goiânia, Brazil 85 houses significantly contaminated 200 people evacuated7 houses demolished12, gallon drums (equivalent volume) of waste disposed.Some statistics from this event.
64Goiânia, Brazil Exposure of large number of public: 4 deaths (initially), 5th died in 1994Prussian Blue was administered to 46 individuals49 received doses from 10 to 620 rad249 had some level of radioactive material contamination.112,000 were monitored for radioactive material contamination.Personnel statistics and emergency response from this event.
65Goiânia - Demographics Goiania – population ~1.27 million12th largest city in BrazilIncident involved 3 hospitals in Goiania and 1 in Rio de JaneiroRadiation monitoring performed at soccer stadiumWhere this event took place.GoianiaRio de Janeiro
66Radiological Dispersal Small Scale Release Example
67London, UKNov. 1, 2006 – Former Russian Agent is intentionally poisoned with 5 uCi or about 1 microgram of Po-210.Fell ill within 4 hours and admitted to hospital.MD suspected poisoning and radioactivity was suggested as a possible cause on Nov. 21.Individual died on Nov. 23.On Nov. 24 death officially linked to major dose of radioactivity ingestion.There have been over 12 criminal acts involving the use of radioactive material/radiation to specifically cause death or injury since about Most in the USSR though one occurred in Texas in Po-210: T ½ = 138 days, MPBB = 0.03 uCi or 7 nano grams, suspected 5 uCi ingestion or about 1 microgram or a sphere of about 0.6 mm in diameter
68London, UK 30 locations identified as being potentially contaminated By Dec. 5, 2006, 3,233 individuals called the British Health Services regarding possible radiation exposure (244 were identified in the group for follow-up)238 hospital workers were investigated for possible exposure (71 received further testing)All initial tests were negative, though an additional 7 individuals were found to have some level of Po-210 contamination on Dec. 7, 2006 (hotel staff).After actions from this contamination event… equivalent to a small scale RDD (w/o detonation).
69London, UKIn 2007, UK authorities reported that a total of 735 people were tested for Po-210 exposure.596 not contaminated.120 showed probable contact with Po-210 but at levels indicating no health risks.17 showed levels “not significant enough to cause any illness in the short term and any increased risk in the long term is likely to be very small”.Medical statistics.
71Hospital Radiological Response No healthcare worker (world wide) has ever received a radiation dose in excess of established radiation dose limits while caring for a contaminated individual.In General life saving medical care should always take precedence over contamination control.
72Hospital Radiological Response Is a nuclear medicine department present.Is a physicist present (particularly a health physicist).Are there portable radiation instrumentation available (survey meters).Does the hospital have an established protocol for emergency response to radiological events.
73Calling for HelpREAC/TS – Radiation Emergency Assistance Center / Training SiteLocated in Oak Ridge, TN24/7 Availability– ask for REAC/TS1-800-NUCLEAR (State of Washington)If you need assistance.
74ReferencesPlanning Guidance for a Response to a Nuclear Detonation, Homeland Security Council, Jan. 2009Planning Guidance for Protection and Recovery Following Radiological Dispersal Device and Improvised Nuclear Device Incidents, FEMA, DHS, Aug. 2008Management of Terrorist Events Involving Radioactive Material, NCRP Report No. 138, Oct. 2001NRC Review of the Tokai-Mura Criticality Accident, US Nuclear Regulatory Commission, April 2000The Radiological Accident at Goiania, International Atomic Energy Agency, 1988Health Effects from Low Level Ionizing Radiation, Biological Effects of Ionization Radiation (BEIR) VII Committee, 2006Review of Criticality Accidents, Los Alamos National Laboratory, 2000Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, US Environmental Protection Agency, 1992.Guidance for Radiation Accident Management, Radiation Emergency Assistance Center / Training Site, REAC/TS, Web Document.Incident of Radioactive Materials Discovered in Scrap Yard Dealer Shops in New Dehli, Government of India, Atomic Energy Regulatory BoardReferences.