radiation protection module 1 Flashcards
The energy emitted and transferred through space than can either be in the form of waves or particles is called ______.
Energy transfer from one place to another
Radiation
2 sources of radiation exposure to humans
- natural or background radiation
- man-made or artificial
have always been a part of the human environment since the formation of the universe
Natural or Background Radiation
from radioactive materials in the crust of the earth. Radioactive material is also found throughout nature such as in soil, water, and vegetation.
terrestrial
The major isotopes of concern for terrestrial radiation
uranium and the decay products of uranium
Radium
Radon
Thorium
radiation from the sun (solar) and beyond the solar system (galactic)
Cosmic Radiation
Ionizing radiation created by humans for various uses
Man Made or Artificial
Radiation has always been present in our body and the everyday we use
Internal Radiation from Radioactive atoms
examples of man made or artifical radiation
- nuclear fuel
- nuclear fallout and accidents
- air travel
- radioactive commercial products
- medical use
- Develop over a long period of time
- Due to both high and low exposures to ionizing radiation
late effects of radiation
2 types of late effects of radiation
somatic and genetic
Effect is seen in the EXPOSED INDIVIDUAL
somatic
occur in future generations as a result of damage to the germ cells
genetic
HEALTH EFECTS OF RADIATION
stochastic (probabilistic) effects
deterministic (non stochastic) effect
______ and ____ are
stochastic effects governed by probability
Cancer induction and genetic effects
- also referred to as the statistical response
- increasing the dose increases the probability of damage, but the severity of the effect is independent of the dose
Stochastic (Probabilistic) Effect
Examples of Deterministic (Non Stochastic)
Effect
Examples are radiation burns, cataracts, erythema, fibrosis, and hematopoietic damage
- A health effect that requires a specific level of exposure to ionizing radiation before it can occur
- Increases as the dose of exposure increases and considers a minimum threshold, below which no detectable clinical effects occur.
Deterministic (Non Stochastic)
Effect
In these Recommendations, the Commission also clarifies how the fundamental principles apply to radiation sources and to the individual, as well as how the source-related principles apply to all controllable situations.
Principles of Radiation Protection
The Commission continues to regard these principles as fundamental for the system of protection and has now formulated a single set of principles that apply to planned, emergency, and existing exposure situations.
Principles of Radiation Protection
FUNDAMENTAL PRINCIPLES OF RADIATION PROTECTION
JOD
justification
optimization
dose limits
“Any decision that alters the radiation exposure situation should do more good than harm”
justification
Exposure of workers incurred as a result of their work
Occupational Category
This principle is source-related and apply in all exposure situations.
It is any decision that alters the radiation exposure situation should do more good than harm.
This means that, by introducing a new radiation source, by reducing existing exposure, or by reducing the risk of potential exposure, one should achieve sufficient individual or societal benefit to offset the detriment it causes, such as the other risks and the costs and benefits of the activity.
justification
Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation
Public Category
Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
Medical Category
Unexpected situations that may require urgent protective actions
Emergency Situation
Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted
Planned Exposure Situation
Situations that already exist when a decision on control has to be taken
Existing Exposure Situation
UNJUSTIFIED EXPOSURE
- increasing radioactivity in products
- radiological exams without clinical need
- screening of asymptomatic population
This principle is source-related and apply in all exposure situations.
The likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable, taking into account economic and societal factors.
This means that the level of protection should be the best under the prevailing circumstances, maximizing the margin of benefit over harm.
optimization
ALARA
as low as reasonably achievable
The greater time of exposure, the _____ dose received.
greater
DISTANCE
We can say that their relationship is _______
inversely proportional to the square of distance
INVERSE SQUARE LAW
This refers to how long an individual is exposed to ionizing radiation
time
This refers to the distance of the subject to the source of radiation.
Distance
Some examples of shielding
- lead aprons
- lead glasses
- thyroid shields
- portable or mobile lead shields
provides a barrier between you and the source of the radiation.
shielding
is always aimed at achieving the best level of protection under the prevailing circumstances through an ongoing, iterative process that involves:
- evaluation of the exposure situation, including any potential exposures (the framing of the process);
- selection of an appropriate value for the constraint or reference level;
identification of the possible protection options; - selection of the best option under the prevailing circumstances; and
implementation of the selected option
optimization
CARDINAL RULES
less time spent near source = less radiation received
greater distance from source = less radiation received
behind shielding from source = less radiation
This principle is individual-related and applies in planned exposure situations.
dose limitation
Level of dose in EMERGENCY EXPOSURE situations and EXISTING EXPOSURE situations.
reference level
Level of dose in PLANNED EXPOSURE situations with the exception of medical exposure of patients.
dose constraint
used in medical diagnosis to indicate whether, in routine conditions, the levels of patient dose or administered activity from a specified imaging procedure are unusually high or low for that procedure.
diagnostic reference level
OBJECTIVES OF RADIATION PROTECTION PROGRAM
for humans
Prevent harmful effects (Deterministic and Stochastic)
Reduce the risk of cancer and heritable effects to the extent reasonably achievable (ICRP 2019)
aims to reduce unnecessary radiation exposure with a goal to minimize the harmful effects of ionizing radiation
RADIATION PROTECTION
OBJECTIVES OF RADIATION PROTECTION PROGRAM
for environment
- the maintenance of biological diversity the
- conservation of species
- the health and status of natural habitats, communities and ecosystems
The Radiation Protection and Safety Program shall include the following information, as may be applicable:
- description of radiation protection and safety org
- description of duties and responsibilities of Radiological Health and Safety Officer (RHSO)
- description of radiation facility
- number and type of equipment
- arrangement for the assessment of the occupational exposure workers
- methods for implementatiom
- methods for evaluating the performance
- an emergency plan for responding to any accident
dose limits of WORKER
(a) effective does of 20 mSv per year averaged over five consecutive years
(b) effective dose of 50 mSv in any single year
(c) equivalent dose to the lens of the eye of 150 mSv in a year
(d) equivalent dose for extremeties (hands and feet) or skin of 500 mSv in a year.
responsibilities of licensee (3)
- each licensee shall be responsible for the protection of workers from occupational exposures
- each licensee shall ensure that policies, procedures and organizational arrangement are established
- all licensee shall ensure that workers are provided with the ff:
- suitable facilities
- health services
- protective devices
- training protection and safety
- all necessary condition to promote safety culture
dose limitation condition of YOUNG APPRENTICES, TRAINEES and STUDENTS
(1) no person under age of 16 shall be subjected to occupational exposure
(2) no person under the age of 18 shall be allowed to work in controlled ared unless supervised and for training purposes only
dose limitation for YOUNG APPRENTICES, TRAINEES and STUDENTS
(a) effective dose of 6 mSv in a year
(b) equivalent dose to the lens of the eye of 50 mSv in a year
(c) equivalent dose to the extremities or the skin of 150 mSv in a year
conditions for pregnant workers
(1) a female worker shall notify the licensee abt her pregnancy in order for her working condition to be modified
(2) each licensee shall modify the working conditions of the pregnant worker
(3) each licensee should make an effort to avoid the exposure rate of the pregnant worker to not exceed 1 mSv in a year
DOSE LIMITS FOR MEMBERS OF THE PUBLIC - RESPONSIBILITIES
(1) each licensee shall ensure that protection and safety policies are established and implemented
(2) each licensee shall be responsible for the establishment, implementatiom and maintenance of measures for ensuring the safety of sources under their responsibilty
DOSE LIMITS FOR MEMBERS OF THE PUBLIC - CONTROL OF VISITORS
(1) ensure that visitors be accomopanied in any controlled area by a knowledgeable person
(2) provide information and instruction to visitors before entering a controlled area
(3) ensure that adequate control over entry of visitors to a supervised area be maintained and appropriate signs posted in such areas
dose limitation - MEMBERS OF PUBLIC
(a) effective dose of 1 mSv in a year
(b) in special circumstances, an effective dose of up to mSv in a single year provided that the average dose over five consecutive years does not exceed 1 mSv per year
(c) equivalent dose to the lens of the eye 15 mSv in a year
(d) equivalent dose to the skin of 50 mSv in a year
each licensee shall ensure that the dose to children visiting patients whi have ingested radioactive materials should be less tha ___ mSv
1 mSv
each licensee shall ensure that doses of comforters and visitors of patiend will not exceed ___ mSv
5 mSv
DOSE LIMITS
occupational exposure - stochastic effect
ICRP
NCRP
annual of both
ICRP - 20 mSv/year averaged over 5 years, not to exceed 50 mSv in any one year
NCRP - 10 mSv X age
annual of both: 50 mSv/year
DOSE LIMITS
deterministic effect
ICRP
NCRP
ICRP 150 mSv/year
NCRP 150 mSv/year
lens of eye
skin, hands, and feet
ICRP
NCRP
ICRP - 500 mSv/year
NCRP - 500 mSv/year
DOSE LIMITS
embryo/fetus
ICRP
NCRP
ICRP - 0.5 mSv/month
NCRP - 1 mSv to the abdomen surface
DOSE LIMITS
negligible individual dose (annual)
ICRP
NCRP
ICRP - no statement
NCRP - 0.01 mSv/yr
ICRP
International Commission on Radiological Protection
NCRP
National Council on Radiation Protection and Measurement
1 sievert = ___ roentgen
100 roentgen
unit that compares radiation exposure to the amount you get naturally from eating a banana
Banana Equivalent Dose
natural source of radioactive isotopes
banana
a level of average annual excess risk of fatal health effects attributable to irradiation, below which further effort to reduce radiation exposure to the individual is unwarranted
negligible individual risk level (NIRL)
establishes a boundary below which the dose can be dismissed from consideration and set the annual NID at 0.01 mSv effective dose
negligible individual dose
