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Module 2 Health and Medical Effects. Health and Medical Effects. Terminal Objective: DESCRIBE the indicators, signs, and symptoms of exposure to radiation. Health and Medical Effects. Enabling Objectives: LIST the major sources of natural background and man-made radiation.
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Health and Medical Effects Terminal Objective: DESCRIBE the indicators, signs, and symptoms of exposure to radiation.
Health and Medical Effects Enabling Objectives: • LIST the major sources of natural background and man-made radiation. • STATE the average annual dose to the general population from natural background and man-made sources of radiation. • DESCRIBE the purposes of radiation dose limits and the guidance for emergency doses.
Health and Medical Effects Enabling Objectives (continued): • DESCRIBE acute radiation dose and chronic radiation dose and the possible effects of each. • STATE the routes of entry by which radioactive material can enter the body.
Cosmic Radiation Sources in the Human Body Sources of Natural Background Radiation • Sources in the Earth’s Crust • Radon
Cosmic Radiation • Cosmic radiation comes from the sun and outer space. • At sea level, the average annual cosmic radiation dose is about 26 mrem per year. • The higher the elevation, the higher the dose of cosmic radiation. • The exposure increases about 1 mrem per year for every 100 feet up in altitude.
Terrestrial Radiation Sources in the Earth’s Crust • Ground, rocks, soil, and sand • Sources – natural radioactive elements of radium, uranium, thorium, and potassium
Terrestrial Radiation average in continental U.S.: 28 mrem per year Terrestrial Radiation average in continental US: 28 mrem per year 75 55 40 15 mrem per year
Internal Sources of Natural Background Radiation • Sources in the human body • Food and water in trace amounts • Naturally occurring radioactive materials deposited in our bodies • Combined exposure from internal sources – radioactive dose of about 40 mrem per year
Radon • (Gas) formed from the radioactive decay of uranium in the soil • Can collect in basements • Emits alpha radiation
Man-Made Sources of Radiation • Tobacco products • Medical radiation • Building materials • Domestic water supply
Sources of Radiation NATURAL BACKGROUND mrem/year Cosmic Radiation 26 Terrestrial (Earth’s crust) 28 Internal Sources (body) 40 Radon 200 MAN-MADE SOURCES mrem/year Smoking (Tobacco Products) 1300 Medical X-rays 40 Medical Diagnosis and Therapy 14 Building Materials 7 Domestic Water Supply 5
Sources of Radiation Total of natural background and man-made sources for the average American (non-smoker): 360 mrem per year (about 1 mrem per day) Average due to smoking cigarettes (1 pack a day): 1300 mrem per year (about 3 mrem per pack) Round-trip airline flight across the U.S.: about 5 mrem
Effects of Radiation on Cells • Atoms • Molecules • Cells • Tissues and Organs • Body
Effects of Radiation on Cells(cont.) Some cells are more sensitive: • Blood • Cells that form sperm • Intestinal tract • Hair follicles
Effects on Cells Exposed to Ionizing Radiation • No damage • Repair and operate normally • Damaged and operate abnormally • Cells die
Biological Pathways Inhalation Ingestion Absorption Puncture or Injection
Acute Large dose Short time Chronic Small doses Long time Acute vs. Chronic Radiation Doses
Acute Radiation Dose Exposure to high doses of radiation over a short period of time (minutes, hours, days)
Damage in exposed individual No proven cases of genetic damage to humans passed on to future children Survivors of Hiroshima and Nagasaki: genetic mutations in their children no higher than the general population Biological Effects of Radiation Exposure
Factors Affecting Cell Damage • Total dose • Dose rate • Type of radiation • Area of the body • Cell sensitivity • Individual sensitivity • General state of health
Acute Radiation EffectsDose Less than 50,000 mrem • No symptoms Between 50,000 and 100,000 mrem • Temporary lowering of white cell count Between 100,000 and 200,000 mrem • Hours Later: Nausea, vomiting, diarrhea • No permanent disability
Acute Radiation EffectsDose (continued) Between 200,000 and 450,000 mrem • Vomiting, diarrhea, hair loss • 200,000 mrem lethal for 5% people in 60 days 450,000 mrem • Lethal Dose 50% in 60 days LD50/60 600,000 mrem • Death for most people
Radiation Burns Bronze-coloring, “tanning” of the skin Cloth Red-coloring, Swelling, Blistering Chernobyl Firefighter Victim from the country of Georgia
Beta Burns from Radioactive Fallout Healing Skin, 30 Days after Burn
Effects of Nuclear Detonation • Thermal (flash) injuries from thermal pulse • Shock wave injuries, collapsed buildings • Radiation burns and sickness • Injuries from fires • External/internal contamination • Long-term effects
Thermal Pulse Injury from Nuclear Blast Flash Burns
Fatal Cancer Risk Estimates (Example) • 10,000 mrem dose – extra 0.8% • 1,000 survivors receive 10,000 mrem – estimated 8 extra cancer deaths • 200 cancer deaths from other causes • 208 total cancer deaths
Chronic Radiation Dose Risks A small amount of ionizing radiation received over a long period of time (months, years) Small increase in cancer risk
Estimated Loss of Life Expectancy from Health Risks • Estimated Days Lost • Smoking one pack a day 2250 • Being 25% overweight 777 • Agricultural accidents 320 • Construction accidents 227 • Automobile accidents 207 • Chronic Radiation (1000 mrem per year from 18 to 65) 51 • All industry 50 • Chronic Radiation (100 mrem per year for 70 years) 10 • Medical radiation 6
EPA Guidelines for Emergency Procedures Dose Limit: Maximum radiation dose that a responder is allowed to receive. Purpose of Dose Limit: Allow responders to perform emergency actions, yet keep risk as low as possible
EPA Guidelines for Emergency Procedures* (expected only once in a lifetime) * Minors and pregnant females have much lower limits
Health and Medical Effects • If there are low-level radiation readings, what are the possible sources of radiation? • How much radiation do you receive daily? • If there is radiation from the explosion, could it get onto or into your body? • What happens if radiation gets into the body?