Basic Radiation Training for Responders to Radiological Incidents BASICS OF RADIATION MA Department of Public Health-Radiation Control Program Thomas F. O’Connell Telephone: July 2002

MA Department of Public Health Radiation Control Program 174 Portland Street, 5 th Fl. Boston, MA Emergency Line

+ + + Nucleus Neutrons Protons Electrons (Electron Clouds) Structure of the Atom

 Decay He Nucleus Ejected from Nucleus  has a discrete energy that can be measured and related to the parent Most of the energy associated with 

 Decay 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 + antineutrino - neutrino Three products share energy – therefore beta has a continuous range of energies

 Decay 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 neutrino Gamma Photon

Half-Life Illustration A t = A o e - t or N t = N o e - t Beginning Activity or Number of Nuclei Time (t) Activity (A) or Number of Nuclei (N) How fast the curve changes (short half-life) (long half-life)

Radiation by NumbersRadiation by Numbers

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 Three Steps for Reducing Radiation Exposure

Shielding for ,  and  BASIC CONCEPT is to: Place materials between the source and person to absorb some or all of the radiation

 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 Shielding for ,  and 

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 distance

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

Good Practices Include: Restrict Access Limit Personnel Post Areas Post Procedures Buddy System Be Aware of Your Radiation Environment Methods for Controlling External Exposure

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

Decontamination

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

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 Internal Radiation Exposure part 2

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. Radiation Syndromes and Injury

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 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 (VERY HIGH DOSES-Short Time Frame)

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 Acute Radiation Syndromes (continued)

Average Annual Exposure

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 male3500(10 years) Smoking one pack a day2250( 7 years) Being an unmarried female1600( 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 Weapon Effects Nuclear Weapons EffectsNuclear Weapons Effects

Heat, Blast, Pressure

Deposition of Radioactive Materials

Small Nuclear Devices

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

MAP

Radiation Signs

Respect radiationRespect radiation

Training

To Contact NIAT During Office Hours –MA Radiation Control Program Off Hours Through –MA State Police Nuclear Incident Advisory Team Contact NIAT

Questions?