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PCBM M1T3 > Radiation > Flashcards

Flashcards in Radiation Deck (55)
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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.



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
Effects may not appear
for years following the
Few show specificity
regarding radiation


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
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