Radiation
Neutral Atom (Non-radioactive) Electrons (-) orbit nucleus (the center) consisting of protons (+) and neutrons Has same number of electrons (-) & protons (+) Atomic number (number of protons) determines element
Radiation A Radioactive atom emits radioactivity because the nucleus has too much energy The nucleus breaks down in an attempt to reach a stable state That excess energy may be in the form of particles or waves
Ionizing Radiation In Ionization the electron (-) is removed resulting in an ion pair Capable of causing bodily damage Ionized atom in human DNA may be altered, causing cell death or mutation
Ionizing Radiation Ionizing Radiation Non-Ionizing Radiation Visible light/heat/radio waves/microwaves
Natural Background Radiation Comes from three primary sources: cosmic radiation solar radiation external terrestrial sources
Medical Uses One of it s main uses is to sterilize Electrons, X rays, gamma rays or atomic ions may be used in radiation therapy to treat malignant tumors (cancer) by killing cancerous cells
Industrial Uses Radiography by means of gamma or x rays to determine thickness gauges Radioactive tracers for industry, makes it possible to find a hole in a tube Used to avoid the build-up of static electricity in production of paper, plastics, synthetic textiles Smoke detectors
Radiation Exposures
Radiation Exposures
ALPHA RADIATION Particle travels short distance in air (1-2 ) Inhalation/Ingestion can be harmful/deadly Paper/skin can stop it s penetration 2 Protons 2 Neutrons
BETA RADIATION Particle travels several feet (Hi-Beta- up to 30 ) Can penetrate eyes, skin, causing burns Clothing & turnout gear can absorb most Beta radiation
GAMMA RADIATION Energy waves that travel endlessly Travels at the speed of light Lead, concrete, iron, dense materials needed for protection
X-RAY RADIATION Energy as a result of excess energy from the emission of electrons (-) Lead, concrete, iron can be used as protection
NEUTRON RADIATION Neutrons ejected from the nucleus No Charge (it s neutral) Does not directly cause ionization Unstable and decays by Beta emission Neutron particle can: Be absorbed (if it s slow moving) Collide resulting in instability (if it s fast moving) Shields better with materials that have a high hydrogen content; water, plastic, boron, paraffin, concrete
Types of Radiation 1-2 200 plus 200 plus up to 10 Paper L E A D W A T E R C O N C R E T E
Units of Measurement ROENTGEN Amount of exposure to X-ray or gamma only RAD (Radiation Absorbed Dose) Amount of energy deposited in human tissue REM (Roentgen Equivalent Man) Amount of biological damage System Internationale (SI): Curie (Ci) or Becquerel (bq)- Radiation given off Gray(Gy)-Amount of energy deposited in human tissue Sievert(Sv)-Amount of biological damage
Units of Measurement R (rem) High mr (millirem) µr (microrem) low 1 rem = 1000 millirems 1 millirem = 1000 microrems
Radiation Dose and Rate Rate: The rateat which radiation energy is deposited Measured in microrem, millirem or rem per hour (similar to MPH on a vehicle) Dose: Total Amountof radiation deposited in the body Measured in microrem, millirem or rem (similar to total miles on a vehicle)
Exposure vs Contamination Exposure Occurs in direct contact with the body or when taken into the body Contamination Occurs when the material clings to or saturates clothing, or parts of your body
Emergency Exposure Guidelines EPA has established guidelines for controlling emergency exposures: Guidelines for Control of Emergency Exposures Dose Limit (rem) Activity Performed Condition 5 rem All U.S. yearly dose limit 10 rem Protect Property Where a lower dose limit is not practicable 25 rem Lifesaving or protection of large Where a lower dose limit is not populations >25 rem Lifesaving or protection of large populations practicable On a voluntary basis to personnel fully aware of the risks involved Source EPA 400-R-92-001
Biological Effects Acute Immediate effects due to large doses over a short period Massive cell damage Chronic Smaller doses repeated over time No immediate effects Reproductive or metabolic damage Mutation of unborn Death over a period of time
Radiation Damage Factors Types of Radiation Duration of Exposure Intensity of Radiation Portion of body receiving dose Individual characteristics: Gender Age Health
Radiation Effects DOSE 0 25 rem 25 50 rem 50-100 rem 100 300 rem 340 rem 500 rem > 600 rem SYMPTOM None Mostly none Bone marrow damage, decrease in red/white blood cells Mild/severe nausea, infection, recovery probable Half will die, poor care Half will die, good care Death expected
Radiation-Warning Labels 3 different labels may be used: Placard required Radioactive White-I Radioactive Yellow-II Radioactive Yellow-III Radioactive White-I (nmt 0.5 mr) Radioactive Yellow-II (nmt 50 mr) Radioactive Yellow-III (nmt 200 mr) over 1000 lbs over 1000 lbs Any Amount
Placard Placement When required, they must appear on all four sides of transport vehicle
UN Identification Number UN ID number may appear close to placard Orange sign with black lettering
704 Diamond Located at Fixed Facilities
Packaging
Self Protection C O N C R E T E Time, Distance & Shielding Minimize time in radiation area Maximize distance Use available shielding Inverse square law ½ the distance = 4x the dose
Radiation Radiation is colorless odorless, and tasteless only a meter can detect the presence of radiation Explosions may be a means of dispersing radiation Radiation meters should be deployed at ALL reports of explosions When checking for the presence of radiation, hold meters remote from the body (at arm s length), to avoid exposure to internal organs
Signs and Symptoms of Radiation Exposure Skin Burns Nausea Weakness Respiratory Distress
Chernobyl April 26, 1986 Firefighters exposed to steam cloud Within 15 minutes experienced symptoms 1hr 30 minutes later firefighters were too weak to lift hose 28 Firefighters died Officially 31 people Unofficially 25,000 workers that were sent to clean up the site have since died
Chernobyl 500 microrems - 3 rems
Chernobyl Contamination
NYC Nuclear Device Mortality
Powerpoint prepared by: Capt Carlos Vazquez HazMat Operations