Radbio_11_9 KSW Radiation Protection & Safety(2).txt

Radiation with sufficient energy to separate an electron from its atom is called ______ _______.

Within a RT department there a two major radiation sources. The first  group comprises  ______________(cobalth teletherapy units or linear accelerators) and use xrays,gamma rays, and sometimes electrons.  The second group comprises__________, which uses gamma rays and xrays from sources such as cesium-137, Iridium-192, and Iodine-125.

________particles consisit of  2_______ and 2 ______ and are therefor simply helium nuclei. They are emitted from unstable heavy nuclei such as radium or radon during the decay process. They can travel  only short distances (most can be stopped by a sheet of paper), but they produdce intense ionization  and are therefor ______ _______ radiation. They are extremely hazardous if _________ or ________ but less dangerous if exposure is ________.

The only type of ionizing radiation that doesn't originate from the nucleus are _______ which come from  _______.

_____particles are electrons emitted by he nucleus and may be either positively charged_____ or negatively charged. _______are not stable and exist for a very short time. Whenever _____particles are emitted, they are acompanied by a ________.Both types of ___ particles have the same rest  mass as an electron and are usually emitted from the nucleus at high velocities.Beta particles and energetic electrons are more penetrating than alpha particles and  pose both an_____and an _______threat.

Which kind of radiation is made up of two protons and two neutrons?

Which kind of radiation can usually be stopped by a sheet of paper?

Which kind of radiation is only a hazard if inhaled or ingested?

Which kind of radiation is usually emitted from the nucleus at high velocitis and can be either positively or negatively charged?

Beta particles have a range of ___cm within soft tissue. Metals may be used for shielding, but _________radiation may result. The probability of ________ x ray production is directly proportional to the square of the ______ ______ of the absorber, and inversely proportional to the square of the mass of the incident particle.

Is bremsstrahlung(braking) radiation more likely to occur with alpha or beta particles?

Photons have no _____ or _______.

_______rays are photons emitted from a nucleus. _____rays are extranuclear and the result of rearrangements of electron shells or ________ radiation.
Except for their_____, there is no difference between xrays and gamma rays.

What are the most common types of ionizing radiation used in radiation therapy?

It was not unitl the _____th century that the general public had any exposure to man-made radiation.

____% of radiation exposure of the U.S. populaion comes from  natural background sources.

The main source of natural background radiation ______.

Natural background radiation comes from three sources: _______, __________, and __________,

Natural background radiation comes from three sources: _______, __________, and __________,

______ _______originate from nuclear reactions in space or from our own sun. Although the earth's atmosphere acts as a protective barrier against much of the initial bombardment, the primary ______  ________ interact with molecules in the atmosphere to create other reactive agents , known as ________  ________.

Secondary particles that are created by cosmic rays interacting with molecules in the atmosphere include:______, _____ and ______which go on to produce energetic electrons, ____, and _______.

Exposure is higher at the ____ and at the ______. Latitude, solar cycles, and other factors may account for a variation of ______% in exposure. The intensity varies even more with increasing _________.

Are people  who live on the Eastern Seaboard or  people who live in the the Rocky Mountains exposed to more radiation?

Which make more difference in radiation exposure: latitude or altitude?

The earth is made up of humdreds of materials, many of which are radioactive because of small amounts of long lived isotopes of uranium, thorium, and radium, among others. This is called _______ radiation.  The largest exposure of this type involves ______which is the 2nd leading cause of lung cancer in the U.S.

_______ exposure results from the radioactive materials that are normally present in our bodies. ____ delivers the highest dose to the body.

_____ ______ sources include medical x-rays, nuclear medicine procedures, consumer products such as ____ and ________, nuclear reactors, and the fuel cycle and fallout from above-ground nuclear weapons testing. All____ ____ sources make up ____% of the ionizing radiation exposure in the U.S.  _____% of that is medical xrays. etc.

Is radon exposure greater in the U.S. or in Kerala region of India?

Most of the radiation which the general population is exposed comes from _____ _______ radiation, smokers excluded.

________ is defined as the amount of ionization produced by photons in air per unit mass of air.The traditional unit for _______ is the _____.

Exposure is defined ONLY for ionization produced by photons interacting with_______.

_______  is defined as the energy absorbed per unit mass of  ANY MATERIAL. The traditional unit for ______ is the ______ which is defined as 100 ergs of energy absorbed per gram of the absorbing material The SI unit is the _______.

For most interactions between photons and soft tissue(most tissue OTHER than BONE), the numeric values for rad and the exposure in R(Roentgen) will be the same to within ______%

__________ takes into account the fact that different types of radiation produce different amounts of radiation in the body. to account for the differencs in biologic effects from different kinds of radiation, each type of radiation is assigned a _____ _____(___).

The traditional unit for exposure is the _____, and the SI unit is __________. The traditional  absorbed dose unit is the _________. The SI unit for absorbed dose is the _____. One  cGy =_______, or 100 rads = _______. The traditional unit for dose equivalent is the ______, and the SI unit is the_______. 100 rems= 1______.
The traditional unit for activity(disentegration) is the_____  and  the SI unit is the _______.1 curie (Ci) = 3.7 × 10v10 Bq

For photons and most electrons the quality factor is ______.

Quality factors for Various Ionizing Radiations:
Xrays and gamma rays(photons): ____
Beta particles, positrons, muons______
High-energy external protons______
Protons other than recoil protons in energy >MeV_____
Thermal Neutrons_______
Fast Neutrons______
Alpha Particles_____
Fission fragments, other heavy nuclei_____

Quality factor for Alpha particles:

Quality factor for xrays and gamma rays(photons)?

Quality factor for beta particles?

Quality factor for positrons?

Quality factor for muons?

Quality factor for high energy protons?

Quality factor for protons, other than recoil protons and energy >2MeV?

Quality factor for thermal neutrons?

Quality factor for fast neutrons?

Quality factor for alpha particles?

Quality factor for fission fragments, other heavy nuclei?

Which types of radiation have a quality factor of 20?

Which types of radiation have a quality factor of 1?

__________takes into account the effect of irradiation of only part of the body or nonuniform irradiation of the body.

1 Ci =________mCi, 1mCi = ______µCi

A _____ is an instrument that has a chamber filled with gas that is ionized in part or whole when radiation is present.
Either the total quantity of the ____ ______ is measured or  the rate at which charge is _______ is ________. Two kinds of ________ may be found in a radiation therapy department. The ________ and the ________.

Describe a gas- filled detector:

Which kind of radiation detector, because of it sensitivity, is better suited for finding contaminaion and oher low levels of radiation?

When______ _____ are properly calibrated, their accuracy approaches _______, which makes them suitable for measurement of the radiation output of  therapy equipment.;

Beause ionization chambers are not very _____, they are not suitable for detection of low levels of radiation or radiation contamination.

Because of their small size ,_________ are widely used to measure radiation in a number of applications. ________materials(LiF among others) give off light when heated. At a later time the crystal is heated to 100-200 degrees and the amount of light it given off is a measure of the dose recieved by the crystal.TLDs are used in mailed intercomparison of therapy unit calibration, in ring badges used for personnel monitoring, and for measurements of enviormental levels of radiation.

The atomic number of ___ is close to that of tissue so ________mimics tissue closely and is therefore useful as a patient of phantom dosimeter.

After development, xray film exposed to radiation turns _____. The amount of _______ is called _______and is related to the amount of radiation received by film. The actual relationship is NOT ________ and depends on the type of film, the type and energy of the radiation, and the details of the processing of the film. However, once calibrated, film is a convenient and inexpensive way to provide imformation about doses received by individuals working in or visiting areas where radiation may be present.

A typical ______has a slot in which film(in it's protective paper cover) may be placed in several thin metal ______ that surround portions of the film. The _____ allow discrimination between different types  and energies of radiation. ________ energy radiation will not penetrate any of  the _____ but can reach the film in the area where no _____ are present. ________ energy radiation will penetrate the _____ and the _____ areas but will not get through the lead ______. High -energy radiation penetrates all areas.

The primary job of _________ agencies is to analyze the existing data related to radiation exposure and to assess the risks associated with these exposures. These agencies can then develop recommendations for dose limits.

Some of the advisory agencies include:

The primary job of ______ agencies is to liscense users of radioactive materials, and radioactive producing equipment, inspect such users, and enforce the appropriate laws.

Some of the regulatory agencies include:

regulatory or advisory agency: EPA?

Is OSHA a regulatory or advisory agency, and what does it stand for?

Is the NRC a regulatory or advisory agency, and what does NRC stand for?

Is the DOT a regulatory or advisory agency, and what does DOT stand for?

Is the NCRP a regulatory or advisory agency, and what does NCRP stand for?

Is the ICRP a regulatory or advisory agency, and what does ICRP stand for?

Is UNSCEAR a regulatory or advisory agency, and what does UNSCEAR stand for?

Is NAS-BEIR regulatory or advisory agency, and what does NAS-BEIR stand for?

Is the FDA a regulatory or advisory agency?

Is the DOT a regulatory or advisory agency, and what does DOT stand for?

Which agency regulates the the transportation of radioactive materials?

Which agency regulates the use of machines that produce radiation such as xray units and linacs?

Which agency oversees the use of isotopes produced in nuclear reactors commonly used in nuclear medicine departments, in laboratories, and as sources for teletherapy(eternal beam radiation) and brachiatherapy.

We have far greater knowledge of the effects of ___doses of radiation than ____ doses.

In sufficiently high doses, radiation can be ______.
A single whole-body exposure of approximately_____Gy is lethal for 50% of the exposed population in 30 days. In other words, the LD50/30 is ______.

LD50/ 30 is _____Gy.  LD50/30 is considered a _____ dose.

Effects related to radiation fall into two general classifications:________ and non_________.

_________effects are those for which a threshold exists and for which severity of the effect increases with dose. Examples of ______ effects are  erythema, _____, _______, and infertility.

______ effects are those that have NO THRESHOLD and for which the probability of occurance is a function of the dose. In this case the severity of he effect is NOT A FUNCTION OF THE DOSE. Examples of _____ effects include_______ induction, _______,and _________.

Because of a lack of threshold dose, _______ effects are of more concern at ____ levels of radiation.

The overall risk of exposure to radiation is approximately ____ in ______ persons per rem.

In terms of embryologic and teratogenic effects, the NCRP assigned a total overal risk estimate of _____ in _____ per Gy