Radiation Flashcards
What is the truth about radiation in the environment?
It is everywhere and you cannot avoid it
Where does background radiation originate from?
Comic rays
Naturally occurring radiation in materials and living things
What is ionizing radiation produced by?
Unstable atoms having excess energy, mass, or both
Trying to reach stability
What are the 5 types of ionizing radiation?
Alpha, Beta, Gamma, X, and Neutron
What is alpha radiation?
Heavy, very short-range particles, travels only a few inches in the air, not an external hazard
Can’t penetrate clothes and not really skin but bad inhaled, eaten or goes near open wounds
Cannot be identified with standard instruments
What are examples of alpha radiation?
Radium, radon, uranium
Describe beta radiation.
Ejected electron that can travel several feet in the air and can penetrate human skin to the germinal layer
High levels of beta-emitting contaminants
Harmful if deposited internally and needs special instruments to be detected
What are examples of beta radiation?
Strontium-90, carbon-14, tritium and sulfer-35
Describe gamma and X radiations.
Highly penetrating electromagnetic radiation and can travel many feet in the air and can travel on human tissue
Can penetrate most materials and is easily detectable by survey meters with sodium iodide detector probe
What are some examples of gamma and X radiation?
Emission of alpha and beta rad in radioactive decay
Iodine-131, cesium-137, cobalt-60, radium-226
Where could neutron radiation be found?
Nuclear power plants, high altitude flight and some industrial sources
How is radiation measured in the US?
Gradation absorbed dose, dose equivalent, and exposure measured in rad, rem, or roentgen (R) and are all considered equal
How is exposure measured?
Estimating curies (Ci)
The greater the Ci the ____ the radioactivity and emitted radiation.
Greater
What is the international system for radiation measurement?
Gray (Gy) and sievert (Sv) for absorbed dose and equivalent dose
What does it mean to measure radioactivity?
The size or weight of a material does not indicate its activity level
Measured in curies per unit mass and depends on the half life
What is the SI unit for radioactivity?
Becquerel (Bq)
Radiation exposure should be limited—-
As Low As Reasonably Achievable (ALARA)
What are the general rules of ionizing radiation injuries?
Damage increases proportionally to exposure Effects may not appear for years following the exposure Few show specificity regarding radiation etiology
What are the most studied groups of those who suffer from radiation?
Atomic bomb survivors
Marshall islanders
Chernobyl survivors
Describe characteristics of atomic bomb survivors?
Wide variety of malignancies
Overall incidence inc in proportion to rad dose
Breast cancer, leukemia, thyroid
Gene mutations, chromosome aberrations
What occurs when a radiation injury effects blood forming tissues?
Highly radiosensitive and changes can occur within minutes after a 1 Sv dose
Profound depression in WBC and platelets in 3-5 weeks
10 Sv is lethal over minutes or days
What can happen to the eye in ionizing radiation injuries?
Lens can obtain vision impairing cataracts in 2-3 Sv in a few minutes
What happens to the reproductive organs in an ionizing radiation injury?
Sperm count depression in both tests (.15 Sv) Permanent sterility (4 Sv)
What occurs in carciongenesis?
Linked to radiation since roentgen discovery based on the radiation equipment
What occurs in leukemia due to ionizing radiation injuries?
All major forms increase
following whole body or major hematopoietic system exposure
Increase appears 2-5 yrs
following exposure
Incidence of cases dose
dependant
Possible excess exposure to nuclear plants
What occurs in breast cancer due to ionizing radiation injuries?
Dose-dependent inc
5-10 yrs following exposure and first age of exposure
May be no threshold effects
What occurs in thyroid due to ionizing radiation injuries?
Malignancies seen in all major groups of exposed to radiation
Tumors primarily adeomas/carcinomas with low mortality and latent periods of 10-25 yrs
Females and younger ppl more incidence
Describe radon.
Colorless, odorless, naturally occurring, radioactive gas formed from decay of radium
Found in confined areas like basements or in rocks and spring water
What is the major health concern of radon?
Radon daughters which produce alpha particles and lodge in respiratory tract
Is radon found in public water supply?
No
What element contains radon and might cause lung cancer?
Uranium
What does the EPA recommend as the standard for non-mining indoor radon levels?
4 pCi/L of air
What is non-ionizing radiation
Energizes or excites molecules without breaking them apart
Series of energy waves composed of oscillating electric and magnetic fields traveling at the speed of light
Where would non-ionizing radiation be found?
Power lines, electrical appliances, TVs, video displays, radar, microwaves
What are the different types f non-ionizing radiation?
Extremely low frequency (ELF) Electromagnetic fields (EMF) Magnetic Resonance Imaging (MRI) Radiofrequency and Microwave rad (RF) Ultraviolet (UV) Ultrasound
Describe extremely low frequency (ELF) radiation.
Produced at 60 Hz, produced by power lines and electrical wiring
Can effect Ca homeostasis, chromosome damage/RNA transcription, cell response to hormones and enzymes and NTs, cellular immune response and interacts with cancer cells
Describe electromagnetic fields (EMF).
Include 50-60 Hz wave lengths
Associated with alternating currents in electric power generation, power lines
Describe radiofrequency (RF) and microwave radiation (MW).
MW absorbed near the skin, RF maybe absorbed through body
Damage through heating
What is the larges source of RF and MW?
Microwave ovens
What are the health concerns of RF and MW?
Neurologic, behavioral, reproductive, teratogenic
Describe infrared radiation (IR).
Skin and eye absorb infrared radiation (IR) as head
Furnaces, heat lamps, IR lasers
What are the health related effects of IR?
Skin (sunburns), eye (opacities)
Describe ultraviolet light (UV).
High photon energy range
No immediate symptoms of excessive exposure
Sun, black lights, welding arcs and UV lasers
What are the health related effects of UV light?
Inc skin exposure and exposure to artificial light
Skin damage, melanotic skin cancer, non-melanotic skin cancer
Describe video display terminals (VDTs).
Radiation non-issue
No harmful emissions
L.A.S.E.R.S.
Light Amplification by Simulated Emissions of Radiation
Describe lasers.
Produce coherent, tightly focused beams of x-ray, UV, visible, or IR rad
Emit optical radiations, eye and skin hazard
What are the health effects of lasers in medical use?
Type, power output, viewing angle, length of exposure
What are some adverse heath effects of lasers?
Skin - erythema, blistering, incineration
Respiratory tract effects due to airborne contaminates produced
Eye - epthelial stripping, granuales, haze, opacities, depends on exposure type, dependent on whether exposure is infrared, UV, or visible
Class I laser
No risk even if viewed directly
Class II laser
No injury if direct beam is viewed for 0.25 sec or less; low risk
Class IIA laser
Output not intended to be viewed; exposure must not exceed class I radiation for 1,000 sec
Class III laser
Can produce eye injury if beam is viewed even momentarily; moderate risk
Medical surveillance required
Class IV laser
Even diffuse reflection can produce eye damage; can injure skin and may pose fire hazard
Medical surveillance required
