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Basic Radiation Training for Responders to Radiological Incidents. BASICS OF RADIATION. MA Department of Public Health-Radiation Control Program Thomas F. O’Connell Telephone: 617.983.6891 email: thomas.f.o’connell@state.ma.us July 2002. MA Department of Public Health
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Basic Radiation Training for Responders to Radiological Incidents BASICS OF RADIATION MA Department of Public Health-Radiation Control Program Thomas F. O’Connell Telephone: 617.983.6891 email: thomas.f.o’connell@state.ma.us July 2002
MA Department of Public Health Radiation Control Program 174 Portland Street, 5th Fl. Boston, MA 617.727.6214 Emergency Line 617.727.9710
Structure of the Atom Nucleus Neutrons + + + Protons Electrons (Electron Clouds)
Decay + + + + + + + + + has a discrete energy that can be measured and related to the parent 4He Nucleus Ejected from Nucleus Most of the energy associated with
Decay antineutrino + + + + + + + + + + - neutrino Three products share energy – therefore beta has a continuous range of energies Either too many neutrons or too many protons Take away + charge and change a proton into a neutron Take away - charge and change a neutron into a proton
Decay + + + Gamma Photon + + + + + + - neutrino • Emission of a photon from the nucleus • Often occurs after or when nucleus is in an excited state • Given off with discrete energies • Can measure photon energy and possibly identify parent
Half-Life Illustration Beginning Activity or Number of Nuclei How fast the curve changes (short half-life) (long half-life) Activity (A) or Number of Nuclei (N) Time (t) At = Aoe-t or Nt= Noe- t
Three Steps for Reducing Radiation Exposure • Time: • reduce time spent in radiation area • Distance: • stay as far away from the radiation source as possible • Shielding: • interpose appropriate materials between the source and your body
Shielding for , and BASIC CONCEPT is to: Place materials between the source and person to absorb some or all of the radiation
Shielding for , and • radiation: no shield required for external exposures; clothing, dead skin layer stops ’s, • radiation: ranges of meters in air; some can penetrate dead skin layer; thin plexiglass shields adequate, bunker gear effective for low energy • x and radiation: highly penetrating, best shields are dense materials (lead), vehicles can be used as shields
Control of distance Control of Distance • Remote Operation • manipulating devices, remote handling tools • Moving Away from Sources • remain near a source only when necessary • treat medical needs of patient/victim first • Secure and Remove Other Radiation Sources • waste containers at Hot Zone/Cold Zone • other unnecessary sources
Control of Time • Practice Mission in Background/Low Dose Area • Spend Down Time in Low Dose Location • (Dose Rate)(Time) = Dose • 10 mR/hr x ½ Hour = 5 mR • Use Respirators to Minimize Internal Intake
Methods for Controlling External Exposure Good Practices Include: Restrict Access Limit Personnel Post Areas Post Procedures Buddy System Be Aware of Your Radiation Environment
Decontamination • To Make Safe by Removing the Unwanted Materials • Chemical Decon Techniques Work for Radioactive • Most Radioactive Contamination is on Surfaces • Removal of Outer Clothing is Very Effective • Remove Clothes and Wrap Patient in Sheets • Enforce Clean Zones and Hot Zones
Internal Radiation Exposure INTERNAL RADIATION EXPOSURE Radioactive Material Deposited in the Body Pathways Inhalation of Dust, Mists or Fumes Ingestion of Contaminated Food or Water Injection Via Puncture Wound Absorption Through Skin or Via a Wound
Internal Radiation Exposure part 2 • Internal Radiation Exposure • Rarely any method to reduce exposure once in the body • ILong physical and biological half-life, may irradiate individual for rest of life • Estimates of dose are complex • Metabolism • Complex biological process of elimination and concentration • High biological variability • Fraction of energy released deposited in other organs
Radiation Syndromes and Injury At low doses, Radiation Injury is a Statistical Probability In all cases, the effects of radiation injury will be delayed Somatic and genetic effect of low level radiation stochastic and non stochastic biological effects Primary biological effect of radiation is cancer.
Radiation Syndromes and Injury The more frequently cells divide, the more sensitive they are to radiation injury. The more specialized the cells are, the less sensitive they are to radiation injury.
Acute Radiation Syndromes(VERY HIGH DOSES-Short Time Frame) Between 0 and 100 rads Generally there is no clinically observable changes Some nausea at the high end of range in more susceptible persons Some blood changes above 25 rads 100 - 400 rads The hematopoietic system is affected Blood cell precursors are very radiosensitive Gradual depression in blood count over days or weeks Increased susceptibility to infection and hemorrhage Most recover at lower end of range with some medical care
Acute Radiation Syndromes(continued) 400-1400 rads Gastrointestinal system is affected Cells lining the intestinal track are radiosensitive Bacteria and toxic material gain entry into the bloodstream Diarrhea, dehydration, infection, toxemia Survival is unlikely at the upper end of range Above 1400 rads Cardiovascular and Central Nervous System is affected Blood supply is impaired leading to nausea, vomiting, convulsions, or unconsciousness. There is no hope for survival LD 50/30 is approximately 450 rads with modest medical treatement
Relative Risk Relative risk of 1-in-a-million chances of dying : • Smoking 1.4 cigarettes ( Lung cancer ) • Spending 2 days in New York City ( Air pollution ) • Driving 40 miles in a car ( Fatal crash ) • Flying 2,500 miles in a jet ( Fatal crash ) • Canoeing for 6 minutes ( Drowning ) • Receiving 40 mrem of radiation ( Cancer )
Risk Perspective Loss of life expectancy (in days due to various causes : • Construction worker • Driving a small car • Being an unmarried female • 25 % overweight • Coffee • Smoking one pack a day • Being an unmarried male • All industry • Radiation (100 mrem/yr -70 yrs) • Alcohol (U.S. average)
Risk Perspective Loss of life expectancy (in days due to various causes : • Being an unmarried male 3500 (10 years) • Smoking one pack a day 2250 ( 7 years) • Being an unmarried female 1600 ( 5 years) • 25 % overweight 777 ( 2 years) • Alcohol (U.S. average) 365 ( 1 year) • Driving a small car 290 • Construction worker 227 • All industry 60 • Radiation (100 mrem/yr -70 yrs) 10 • Coffee 6
Nuclear Weapons Effects Nuclear Weapon Effects
The Dirty Bomb • Radiological Dispersal Device (RDD) • Conventional Explosive and Radioactive Material • Small Localized and Widely Dispersed Scenarios • Dispersal Potential Depends of Physical Form of RAM • Amount of Explosive and Local Weather Drives Dispersion • Low Level Exposures and Contamination Likely • Large Psychosocial Effects - Fear Factor
Contact NIAT Nuclear Incident Advisory Team • To Contact NIAT During Office Hours • MA Radiation Control Program • 617.727.9710 • Off Hours Through • MA State Police • 508.820.2121