Issues in Emergency Preparedness Radiation Radiological Weapons

Issues in Emergency Preparedness: Radiation & Radiological Weapons William Wallace, MS New York City Dept. of Health & Mental Hygiene with David Kotelchuck, Ph. D, MPH, CIH Hunter College (CUNY)

Radiological Overview §Part 1: Ionizing Radiation Review §Part 2: Health Effects of Ionizing Radiation §Part 3: Basic Ionizing Radiation Control Methods §Part 4: Radiological Dispersion Devices

Part 1: Ionizing Radiation Review 3

A Note on the History of Radiation Use

Some Basic Radiation Chemistry & Physics

Atomic Structure Basic Atom = Nucleus + Electrons n nucleus Nucleus Protons & Neutrons u Large mass u Positive charge u n p n Electrons In orbitals u Very small mass u Negative charge u electrons

Radioactive Decay Radioactive decay can be defined as the process by which an unstable atom releases matter/energy during a transition to a more stable form.

Radionuclide: A nucleus which can emit ionizing radiation

Ionization: The removal of electrons from an atom. The chief mechanism by which most radiation particles/rays lose energy when traveling through matter.

Types of Radiation Emissions Type of Radiation Alpha Beta (-) Greek Symbol - Description Charge Rest Mass Combination of 2 protons and 2 neutrons +2 4. 001 amu (6. 64 x 10 -24 g) Electron -1 0. 000549 amu (9. 11 x 10 – 28 g) 0. 000549 amu (9. 11 x 10 -28 g) Positron, or Beta (+) + Positron (antimatter electron) +1 Gamma γ High energy electromagnetic wave 0

Some Basic Types of Radioactive Decay Alpha ( ) Decay - consists of the release of a particle with 2 protons and 2 neutrons, 7300 times more massive than a beta particle, and much slower.

Some Basic Types of Radioactive Decay Beta ( ) Decay - consists of an electron or positron being ejected from the nucleus at a high velocity.

Some Basic Types of Radioactive Decay Gamma ( ) & X-Ray – Following the other types of decay, electromagnetic radiations may be released to further stabilize an atom.

Some Basic Types of Radioactive Decay Neutron (n) Decay – occurs at nuclear reactor sites, but is not an ordinary radioactive decay product. Not relevant for HDP training, other than reactor incidents. (Not covered here).

Penetration of Decay Products in Tissue RANGE IN TISSUE: Alpha - < 100 microns Beta - 0. 0006 - 0. 80 cms Gamma - no fixed range

Half-Life (T n 1/2) Radioactive Half-Life = Time required for a radionuclide to lose 50% of its activity by radioactive decay. 10 Ci 1 half life Ci - Curies 5 Ci

Typical Half-Lives Isotope Half-Life Emission Daughter 3 H 12. 3 yr b- 3 He 14 C 5730 yr b- 14 N 13 N 10 min b+ 13 C 32 P 14. 3 day b- 32 S 238 U 4. 5 X 109 yr a 234 Th

Effective Half-Life in the Body When a radioactive material is placed in the body, it has an effective half-life in the body less than its radioactive half-life. This is due to elimination of radioactive materials by excretion from the body

Measuring Rates of Nuclear Decay: Activity The activity of the radioactive source can be measured in disintegrations per second (dps) or curies (Ci) or becquerels (Bq) 1 Becquerel (Bq) = 1 dps 1 Curie (Ci) = 3. 7 x 1010 dps (37 billion dps)

Harm is Measured in Rems § While activity measures the “strength” of a radioactive source (how many radioactive nuclei decay in a period of time), we are more interested in measuring the harm done by these emissions to the human body. § This depends not only on the number of particles emitted, but also their types (α, β, γ) and energies. § The unit of biological harm is the Rem.

Units of Harm from Radiation Exposure • • • Rad - Units of absorbed energy due to radiation exposures Rem - Unit for measuring biological damage caused by radiation exposures. Can also be expressed in units of millirems (mrem), where 1 Rem = 1, 000 mrems. Sievert (Sv) – An international unit of biological harm, where 1 Sv = 100 Rems

Methods of Detecting Radiation • • Ionization radiation by its nature causes ionization of molecules along the path it travels in matter Typical ionization detectors include: • • “Pancake” gas proportional detectors Geiger-Mueller counters Scintillation detectors Speed film detectors

Configurations of Radiation Detectors • • • Portable Survey Meters: Geiger counters, ion chambers, hand-held scintillators Personal Dosimeters: Film badges, pocket ion chambers, electronic personal dosimeters [EPD] Fixed Instruments: Liquid scintillation counters, gamma counters, gas flow proportional counting chambers, multichannel analyzer spectroscopy systems, whole body counters, gamma cameras

Part 2: Health Effects of Ionizing Radiation

Basic Ionizing Radiation Health Effects

Short Term vs. Long Term Radiation Effects • Short Term (Acute) Effects: effects seen within hours, days, or weeks of an exposure to radiation. Death or Acute Radiation Sickness • Long Term (Chronic) Effects: effects that are seen months, years, or decades after an exposure to radiation. Cancers and Genetic Effects.

Acute Radiation Sickness (ARS) • People exposed to radiation will get ARS only if: The radiation dose was high (doses from medical procedures such as chest X-rays are too low to cause ARS; however, doses from radiation therapy to treat cancer may be high enough to cause some ARS symptoms) Ø

Acute Radiation Sickness (ARS) 1. People exposed to radiation will get ARS only if: The radiation was penetrating (that is, able to reach internal organs), 2. The person's entire body, or most of it, received the dose, and 3. The radiation was received in a short time, usually within minutes. 1.

Acute Radiation Sickness (ARS) • The first symptoms of ARS typically are: nausea, vomiting, and diarrhea. Ø • Symptoms can start within minutes to days after the exposure, will last for minutes up to several days, and may come and go.

Acute Radiation Sickness (ARS) • Then the person usually looks and feels healthy for a short time, after which he or she will become sick again with loss of appetite, fatigue, fever, nausea, vomiting, diarrhea, and possibly even seizures and coma.

Acute Radiation Sickness (ARS) • This seriously ill stage may last from a few hours up to several months. • People with ARS typically also have some skin damage.

Acute Radiation Sickness (ARS) • The chance of survival for people with ARS decreases with increasing radiation dose. • Most people who do not recover from ARS will die within several months of exposure.

Immediate Medical Effects Radiation Dose Delivered to the entire body over a ten minute period: 5, 000 rem: Death, virtually no chance of survival 1, 000 rem: Small chance of survival 350 rem: Approximately 50% chance of death. This dose called LD 50 (Lethal Dose 50) 100 rem: Survival likely; flu-like symptoms. 50 rem: No apparent short-term effects; temporary drop in white blood cell count.

NOTE OF CAUTION: n 5, 000 rad of gamma radiation to the entire body delivered in 10 minutes will result in death. n 5, 000 rad of gamma radiation delivered directly to a cancer tumor mass may save the patient’s life.

Long Term Radiation Effects n Cancers: Exposure to radiation increases incidence of all types of cancer u Typically, leukemias are the first observed cancers, about 10 years after initial exposure n Genetic Effects: These effects show up in future generations as seen among atomic bomb survivors in Japan

Cancer and Radiation Percent Cancer Incidence in Population Complicating factors: Radiation Dose • Background Radiation • Exposures to Other Carcinogens

Cancer and Radiation n Bottom line: Estimated lifetime excess risk is about 5 x 10 -4 (or. 0005) fatal cancers per rem of exposure. n While not precise, the above number is useful is setting regulatory standards. n It also provides workers with some sense of the risks from radiation exposure.

General Rule of Radiosensitivity The most radiosensitive cells in adult humans are: Ø Ø Rapidly dividing cells, such as those in the bone marrow or in tissues lining the intestine Precursor embryonic cells (undifferentiated)

Basic Radiation Exposure Limits (above background) n General public 100 mrem/yr n Radiation worker (occupational exposure) 5000 mrem/yr (to the whole body) 50, 000 mrem/yr (to the extremities) n Fetus 50 mrem/yr

Permissible Levels of Radiation Exposure - Occupational n 5 Rem (or 50, 000 mrem or 0. 05 Sv) annually, whole body. n 50 Rem (or 500, 000 mrem or 0. 5 Sv) annual limit to the skin, the extremities, or any organ other than the lens of the eye. n 15 Rem annually to lens of the eye

NATURAL SOURCES OF BACKGROUND RADIATION Approximately 4. 88 m. Sv or over 400 mrem per year 14 C 7 Be Cosmogenic Radionuclides 3 H Cosmic Radiation 0. 01 m. Sv 0. 3 m. Sv . Internal Radionuclides 40 K 0. 26 m. Sv Inhaled Radionuclides Terrestrial 2. 0 m. Sv 222 Rn 232 Th 238 U 225 Ra 235 U 0. 26 m. Sv

Annual Doses from Natural Background Radiation

What is Radioactive Contamination? • External radiation particles and rays typically pass into the human body, may cause damage there and then pass out of the body. They do not leave the exposed person “radioactive”, that is he/she is not “hot” when measured with a radiation meter.

What is Radioactive Contamination? • However sometimes radioactive materials, such as radionuclides, are deposited on or in a person, and then undergo nuclear decay. In this case we say that the person is contaminated with radiation, and he/she will show signs of radioactivity on a radiation meter.

What is Radioactive Contamination? • So radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people, or animals to become contaminated.

What is Radioactive Contamination? • A contaminated person has radioactive materials on or inside the body, and can either contaminate others, radiate them or both.

What is External Contamination? • External contamination occurs when radioactive material, in the form of dust, powder, or liquid, comes into contact with a person's skin, hair, or clothing. • In other words, the contact is external to a person's body.

What is Internal Contamination? • Internal contamination occurs when people swallow or breathe in radioactive materials, or when radioactive materials enter the body through an open wound or are absorbed through the skin.

What is Internal Contamination? • • Some types of radioactive materials stay in the body and are deposited in different body organs. Other types are eliminated from the body in blood, sweat, urine, and feces.

Annual Limits on Intake (ALI’s) § For persons working with radioactivity in hospital and university labs, Annual Limits on Intake (ALI’s) have been established. § These are the amounts of a single radionuclide taken internally that would irradiate a person to the allowable dose limit for each year of occupational exposure.

ALI’s for Some Common Radionuclides Hydrogen-3 Carbon-14 Phosphorus-32 Iodine-125 Iodine-131 Sulfur-35 Chromium-51 81. 0 m. Ci 2. 0 m. Ci 0. 4 m. Ci 0. 03 m. Ci 2. 0 m. Ci 20. 0 m. Ci

Part 3: Basic Ionizing Radiation Control Methods

Basic Ionizing Radiation Control Methods

Radiation Control Airborne Materials Radiation Contamination Radioactive Material

Time, Distance, and Shielding Time - Limit time spent near radiation sources. Distance - Increase distance between radiation sources and you. Shielding Whenever possible, shield yourself from radiation.

Shielding n Shielding: A body of material used to prevent or reduce the passage of particles or radiation. n One of the main controls for radiation protection n Use proper shielding to limit exposures of radiation workers.

Relative Penetrability of Radiation Through Shielding Materials

NOTE: Do NOT Use Heavy Metals Like Lead to Shield Beta Particles Why not? Because when beta particles (either electrons or positrons) pass through these materials, they emit gamma rays. So the shielding material, designed to stop betas, then becomes a secondary source of gammas. n This process is usually called by its German name, Bremsstrahlung, which means braking radiation. n

Ste el High Energy Beta Shielding High Energy Betas lucite ( ) X-rays (Bremsstrahlung) Use low Z materials, such as lucite, aluminum or copper to shield high energy beta sources

BREMSSTRAHLUNG: Viewed at the Atomic Level Change in energy and direction X-ray (Bremsstrahlung) nucleus Incident beta particle

Radiation Control Airborne Materials Radiation Contamination Radioactive Material

Protective Measures: General Planning Work – all radioactive materials work should be carried out according to some prearranged plan. n Training and Experience – Lack of proper training can often contribute to accidents, or one’s ability to mitigate an accident. n Fatigue and/or Emotional Factors – Be sure you are clear-headed when working with radioactive materials. n

Protective Measures: Basic Precautions n Time – Limit time spent near radiation sources. n Distance – Keep your distance from radiation sources as much as possible. n Shielding – Whenever possible, shield yourself from radiation.

Protecting Personnel • Minimize time in radiation area

Protecting Personnel • Maximize distance from sources of radiation

Protecting Personnel • Use available shielding

Other Protective Measures: External Radiation Protection n Protective Clothing (depending on situation) Gloves – Latex or nitrile depending on nature of material being used u Lab Coats u Respirators u Protective Eyewear u Bandages – must be worn if open cuts or sores exist, to prevent absorption of radioactive materials. u

Personal Protective Measures: Internal Radiation Protection n Good Hygiene – NO eating, drinking, smoking, gum chewing, fingernail biting, etc. , in laboratories to avoid ingestion of radioactive materials. n Surveys u Self contamination and laboratory surveys u Laboratory equipment surveys u Common use equipment surveys u Survey before leaving laboratory

Reportable Events n n Certain situations involving radiation may require the Radiation Safety Office (RSO) to notify the Department of Health. Immediately notify the RSO of: Suspected loss or theft of radioactive material. u Suspected excessive radiation exposure. u Suspected release of excessive quantities of radioactive material to the environment. u

Radiation Warning Signs

Radiation Warning Signs Radioactive Material caution signs must be posted on all containers with more than 10% of an ALI, and in areas where more than 1 ALI is used or stored.

Radiation Warning Signs A Radiation Area is an accessible area greater than 5 mrem/hour at 30 cm from the source.

Radiation Warning Signs A High Radiation Area is an area greater than 100 mrem/hour at 30 centimeters from the source.

Our Goal: ALARA As Low As Reasonable Achievable n This is the standard enforced by the Nuclear Regulatory Commission (NRC), which regulates reactors and research labs – that is, operations be designed so that the work is done in a manner that keeps dose As Low As Reasonable Achievable, but in no case above 5 Rems/yr.

Our Goal: ALARA As Low As Reasonable Achievable n OSHA doesn’t include ALARA in its radiation standard, but this is a good goal to shoot for.

Part 4: Radiological Dispersion Devices

Radiological Dispersion Devices

Radiological Dispersion Devices Dirty Bombs

What is a “Dirty Bomb”? • A dirty bomb, or radiological dispersion device, is a bomb that combines conventional explosives, such as dynamite, with radioactive materials in the form of powders or pellets.

What is a “Dirty Bomb”? • • The idea behind a dirty bomb is to blast radioactive material into the area around the explosion. The main purpose of a dirty bomb is to frighten people and make buildings or land unusable for a long period of time.

Use of Radioactive Materials for Terrorist Attack • Few, if any deaths due to radiation. ? • Possible deaths due to the explosion.

Use of Radioactive Materials for Terrorist Attack • Most likely impact will be psychological. • May also impact the economy.

Radiation Dose Delivery • External Dose • • Source Fragments Fallout Internal Dose • Primarily inhalation pathway.

Radiation Dispersion Devices can vary in complexity and design. Radioactive Source Plastic Explosive

OR Lid w/explosive bolts Needs cooling system to remove heat from radioactive decay Shielding High Level Source Tens of Curies or more Mechanism for introducing explosive charge and detonating weapon

Types of Radiation Dispersion Devices (RDD’s) • Improvised • Purpose Built • Manufactured

Improvised RDD’s • Usually involve targets of opportunity. • Little or no modification of the radiation source needed.

Examples of Improvised RDD’s Use of explosives to scatter radioactive material from a nuclear source, such as: • Source from a radiographic camera. • Explosive placed in a blood irradiator. • Explosive placed in a radioactive liquid. • Explosion of a high level radioactive materials shipment.

Potential Radionuclides Which Might be Used as an RDD • Based on manufactured quantities and availability in the society: • • • Cobalt 60 (Co-60) Cesium 137 (Cs-137) Iridium 192 (Ir-192) Strontium 90 (Sr-90) Americium 241 (Am-241)

Other Possible Radionuclides • • Plutonium (Can be Pu-239 or Pu-238) Uranium 235 (U-235) Thorium Radium

Results from Using Improvised RDD’s • • Precision (and hence results) not predictable. May create a radioactive fragmentation field, as opposed to a widespread fallout pattern.

Purpose-Built RDD’s: Some Examples • • • Grinding a radiography source into a powder and placing it in an explosive charge. Chemically removing Cs-137 microspheres from a Cs. Cl liquid. Cutting Co-60 pins into small pieces for use in a fragmentation bomb.

Results from Using Purpose Built RDD’s • • Achievement of the intended result is more likely than using an improvised RDD. Larger amounts of radioactive material are more likely to be used. Greater down-wind fallout likely. If fragmentation results, a large and possibly high radiation field possible.

Manufactured RDD’s: Assembly Issues • • Expected to involve very large amounts of radioactivity. Requires a large manufacturing facility. Less likely to be located in the target country. Persons with advanced engineering and science degrees needed to make these devices.

Examples of Manufactured RDD’s • • Atomic Weapons Atomic Munitions

General RDD Effects • • • Many fatalities due to explosion. Fewer fatalities due to radiation. Major psychological impact. Major military and economic impact. May result in long term disruption of ordinary life in affected areas.

RDD Population Groups • • Emergency Responders Injured Victims – most likely from: • • • Blast or fire Concussion Shrapnel Burns Potentially or actually contaminated population.

Immediate Actions: • At the scene Medically stabilize the patient. • If possible, decontaminate at the scene. For example remove contaminated clothing. At the Emergency Room • Take care of medical issues first • Then further decontaminate • •

Nature of an Explosive RDD • • Explosion occurs. Radioactive cloud moves downwind. Radiation dose from the cloud itself is a one-time event, but radioactive contamination in the form of settled dust may be left behind. Extent of settling depends on concentration and sizes of radioactive particles in cloud.

As the Cloud Moves Down Wind Radioactive material is deposited as fallout.

Radiation Dose to the Public • Dose from the Plume: • • • Will occur long before evacuation. Highly dependent on wind direction and meteorological conditions. Not likely to be a lethal dose.

Radiation Dose to the Public • Dose from Radioactive Fallout: • • Greatest danger is ingesting and inhaling radioactive materials deposited from fallout. These may exceed public dose limits and EPA Protective Action Guidelines.

EPA Protective Action Guidelines • EPA needs to give guidance to authorities for radiological emergencies, based on exposures of: • 1 to 5 rem for an expected dose that will occur immediately. • Two rem per year for those living on contaminated land.

Surveillance Issues • • • Determine contamination levels. Plume projections helpful. Need teams to survey ground.

Surveillance Issues 1. Sample for loose and fixed contamination: Loose contamination is radioactive material that is easily transferred from one surface to another, and hence more dangerous. 2. Fixed contamination does not move easily. 1. 2. Suitable air, water, and other environmental testing.

Surveillance Priorities • Determine the need for evacuation or sheltering. • • • Find out where the contamination is. Find out the radioactive levels and contaminated areas. Determine populations most likely to be contaminated.

Public Contamination Issues • • • A plan is needed, preferably in advance. Must be for large numbers of people. Must set up temporary staging areas. Must be able to decontaminate quickly. Must be capable of measuring people’s radiation levels. Must establish refugee centers or shelters.

Public Communication Clear Multiple Languages Provide Good Information

Public Communication • • • Can help prevent panic. Can be key to keeping uninjured from going to and overcrowding hospital emergency rooms. Educational materials needed urgently in the wake of the event: • • • What is radiation? What is the danger? What can I do?

Screening and Decontamination • • • Will require a large, well organized plan. Need to mobilize survey meters and trained personnel. Reception areas where public can go need to be surveyed and decontaminated.

Human Factors • • Plan must treat people in a humane and considerate manner. Try to keep families together. Enlist the aid of non-contaminated members of the public. Will require the use of police and other types of security factors for crowd control.

Human Factors • • • Survey and decontaminate those with medical issues first. Effort must include procedures to identify property. Get personnel rapidly to shelters.

Different Types of Long. Term Followup Needed for: • Ingestion of Radioactive Materials • Radiation doses of less than 5 rem • Radiation doses of 5 to 100 rem • Radiation doses of greater than 100 rem

Long Term Environmental Issues • • • How clean is clean? How much added radiation is acceptable? Can items be cleaned safely? Can contaminated areas be mitigated? All require establishment of a long term radiation monitoring program.

Types of Radiological Dispersion Devices

Two Types of Radiation Dispersion Weapons: “Suitcase” Bomb “Backpack” Bomb

“Suitcase” Bomb • • • A “suitcase” bomb is a compact and portable nuclear weapon. Dimensions can be as small as 24 x 16 x 8 in. Contains a single critical mass of plutonium or uranium. Pu-239 critical mass weighs 10. 5 kg and would be 10. 1 cm across. May cause significant explosion equivalent to 10 -20 kilotons of TNT.

“Suitcase” Bomb • The warhead consists of a tube with two pieces of uranium or plutonium which when rammed together will explode, and • Some sort of firing unit, including a coded detonation device, may be included in the “suitcase”.

“Suitcase” Bomb • • Kills people not only with explosion, but also with the radioactive material they emit that can also radioactively disable Radiation can be spread to humans via: External radiation • Contamination • Incorporation of radioactive material into body tissues and organs such as bone, liver, thyroid or kidney •

“Backpack” Bomb • • Another type of portable weapon is a “backpack” bomb. May consist of three “coffee can-sized” aluminum canisters in a bag All three must be imploded to create an explosion Can have a 3 -to-5 kiloton yield

Concluding Remarks • Radiological WMD can be handled either on a local, regional, or national level, using principles and planning discussed previously; partnerships may be established among groups

Concluding Remarks • For “Suitcase Bomb” nuclear explosions of proportions experienced in Hiroshima and Nagasaki, any response must arise from the regional and national plans. • For RDD’s, however, response may be based on local, regional and national plans.