Radiation Protection Chapter 10

Provides the most recent guidance on radiation protection.

NCRP Report No.116 (Limitation of Exposure to Ionizing Radiation)

Set of numeric dose limits that are based on calculations of the various risks of cancer and genetic (hereditary) effects to tissues or organs exposed to radiation.

EfD Limiting System

The sum of both external and internal whole-body exposures is considered when establishing this limit.

EfD

Leading international organization responsible for providing clear, consistent radiation guidance through its recommendations on occupational and public dose limits.

ICRP

Normally a medical physicist, health physicist, radiologist, or other individual qualified through adequate training and experience. This person has been designated by a health care facility and approved by the NRC and the state.

RSO

Evaluates human and environmental exposure to ionizing radiation from a variety of sources, including radioactive materials, radiation-producing machines, and radiation accidents.

UNSCEAR

An annual EfD that provides a low-exposure cutoff level so that regulatory agencies may dismiss a level of effective dose as being of negligible risk.

Negligible individual dose (NID)

An upper boundary limit for radiation workers for yearly whole-body exposure (excluding personal medical and natural background exposure) of 50 mSv.

Annual occupational EfD limit

Optimization for radiation protection.

ALARA Concept

Describes the level of radiation exposure of population or group from low doses of different sources of ionizing radiation.

ColEfD

Training and experience required for an RSO.

10 CFR 35.50 and 10 CFR 35.900 of the Code of Federal Regulations.

Scientific journals published by the ICRP.

Annals of ICRP

Established by health care facilities to trigger an investigation to uncover the reasons for any unusual high exposure received by individual staff members.

Action limits

Strictly an equipment performance standard.

Radiation Control for Health and Safety Act of 1968 (Public Law 90-602)

Responsible for regulations concerning employees' right to know about hazards that may be present in the workplace.

OSHA

Publications that list studies of biologic effects and associated risk of groups of people who were either routinely or accidentally exposed to ionizing radiation.

BEIR reports

Conducts an ongoing products radiation control program, regulating the design and manufacture of electronic products, including diagnostic x-ray equipment.

FDA

Concerns the upper boundary dose of ionizing radiation that results in a negligible risk of bodily injury or hereditary damage.

EfD limit

Agency that has the power to enforce radiation protection standards.

NRC

Lifetime EfD.

Cumulative effective dose (CumEfD) limit

A radiation quantity used for radiation protection purposes when a person receives exposure from various types of ionizing radiation.

EqD limit

Indicates the ratio of the risk of stochastic effects attributable to irradiation of a given organ or tissue to the total risk when the whole body is uniformly irradiated.

Tissue weighting factor (Wt)

Cancerous neoplasms caused by exposure to ionizing radiation.

Radiation-induced malignancy

Federal legislation requiring the establishment of minimal standards for the accreditation of educational programs for personnel who perform radiologic procedures and the certification of such individuals.

Consumer-Patient Radiation Health and Safety Act (Title IX of Public Law 97-35).

Applies to complete x-ray systems and major components manufactured after August 1, 1974

Code of standards for diagnostic x-ray equipment

Why have scientists developed occupational and nonoccupational effective dose limits?

A.) To eliminate all harmful effects of low-level ionizing exposure.

B.) To minimize the risk of harmful biologic effects to the general public, patients, and radiation workers.

C.) To promote radiation hormesis.

D.) To be comparable to the risk occurring in both nonsafe and safe industries.

B.) To minimize the risk of harmful biologic effects to the general public, patients, and radiation workers.

Which of the following concerns the upper boundary dose of ionizing radiation that results in a negligible risk of bodily injury or genetic damage?

A.) Skin erythema dose

B.) Dose limits

C.) ColEfD

D.) EfD limit

D.) EfD limit

Fundamental radiation protection standards governing occupational radiation exposure may be found in which of the following documents?

A.) 5 CFR 10

B.) 10 CFR 20

C.) The ALARA Manual

D.) Public Law 90-602

B.) 10 CFR 20

Which of the following groups are radiation protection standards organization?

1.) ICRP

2.) NCRP

3.) UNSCEAR

A.) 1 and 2 only

B.) 1 and 3 only

C.) 2 and 3 only

D.) 1, 2, and 3

D.) 1, 2, and 3

The NCRP recommends that radiation exposure be kept at which of the following levels?

A.) As low as reasonably achievable.

B.) At threshold levels.

C.) Slightly above upper boundary levels.

D.) At 0.01 mSv/yr.

A.) As low as reasonably achievable.

Which of the following concepts is behind the establishment of the effective dose limiting system?

A.) Negligible risk.

B.) Organ and tissue radiosensitivity.

C.) Radiation hormesis.

D.) Radiation exposure and associated risk of possible radiation-induced malignancy.

D.) Radiation exposure and associated risk of possible radiation-induced malignancy.

The term mutagenesis refers to which of the following?

A.) Irradiation of DNA of somatic cells leading to abnormalities in new cells as they divide in that individual.

B.) Birth defects from irradiation of the unborn child in utero.

C.) Cancer caused by ionizing radiation exposure.

D.) Somatic and hereditary effects of ionizing radiation caused by low-level exposure.

A.) Irradiation of DNA of somatic cells leading to abnormalities in new cells as they divide in that individual.

Somatic effects of ionizing radiation that exhibit a threshold dose below which the effect does not normally occur and above which the severity of the biologic damage increases as the dose increases are classified as which of the following?

A.) Deterministic Effects

B.) Epidemiologic Effects

C.) Probabilistic Effects

D.) Stochastic Effects

A.) Deterministic Effects

Congress passed the Radiation Control of Health and Safety Act (Public Law 90-602) in 1968 to protect the public from the hazards of unnecessary radiation exposure resulting from which of the following?

A.) Diagnostic x-ray equipment only.

B.) Therapeutic x-ray equipment only.

C.) Electronic products, excluding diagnostic x-ray equipment.

D.) Electronic products, including diagnostic x-ray equipment.

D.) Electronic products, including diagnostic x-ray equipment.

Which of the following are classified as late deterministic somatic effects?

1.) Cataract formation

2.) Organ atrophy

3.) Radiation-induced malignancy

A.) 1 and 2 only

B.) 1 and 3 only

C.) 2 and 3 only

D.) 1, 2, and 3

A.) 1 and 2 only

What term is used for a beneficial effect of radiation in populations continuously exposed to low levels of radiation above background?

A.) Nonoccupational EqD effect.

B.) Radiation negligible risk level effect.

C.) Radiation hormesis effect.

D.) Radiation benevolent effect.

C.) Radiation hormesis effect.

In addition to the annual occupational effective dose limit established for radiation workers, the NCRP recommends a lifetime effective dose limit, which is found by multiplying a person's age in years by which of the following subunits?

A.) 1 mSv

B.) 10 mSv

C.) 100 mSv

D.) 1000 mSv

B.) 10 mSv

For members of the general public not occupationally exposed, the NCRP recommends an annual effective dose limit of ____ for continuous (or frequent) exposures from artificial sourcees of ionizing radiation other than medical irradiation and natural background and a limit of _____ annually for infrequent exposures.

A.) 1 mSv , 5 mSv

B.) 3 mSv, 8 mSv

C.) 10 mSv, 20 mSv

D.) 50 mSv, 75 mSv

A.) 1 mSv , 5 mSv

Which of the following is the unit of choice for expressing the collective effective dose?

A.) Group-Gray

B.) Person-Coulomb per kilogram

C.) Person-Sievert

D.) Group-Coulomb

C.) Person-Sievert

A set of numeric dose limits that are based on calculations of the various risks of cancer and genetic (hereditary) effects to tissues or organs exposed to radiation defines:

A.) ALARA concept

B.) Effective dose limiting system

C.) Investigational levels

D.) Risk protocol

B.) Effective dose limiting system

Previously, the NRC was known as the:

A.) AEC

B.) EPA

C.) FDA

D.) OSHA

A.) AEC

The Radiation Effects Research Foundation is a group run by the government of:

A.) The United States, to study the effects of low-level ionizing radiation on populations.

B.) Germany, to study the effects of ionizing radiation on the population.

C.) Japan, primarily to study the atomic bomb survivors of Hiroshima and Nagasaki.

D.) England, to study the development of childhood cancer in children exposed in utero to ionizing radiation.

C.) Japan, primarily to study the atomic bomb survivors of Hiroshima and Nagasaki.

Person-Sievert may be used to express:

A.) Annual occupational EfD for radiation workers

B.) ColEfD

C.) CumEfD

D.) EqD

B.) ColEfD

Which agency is responsible for regulations regarding employees' right to know about hazards that may be present in the workplace?

A.) NRC

B.) All NRC agreement states

C.) EPA

D.) OSHA

D.) OSHA

The Conclusion of BEIR Report No. 5 about the adverse health effects of low levels of ionizing radiation are based on extrapolations from radiation equivalent dose greater than:

A.) 1 mSv

B.) 0.1 Sv

C.) 50 mSv

D.) 0.5 Sv

D.) 0.5 Sv

Because the tissue weighting factors (Wt) used to calculate effective dose are so small for some organs, an organ associated with a low weighting factor may receive an unreasonably large dose even though the effective dose remains within the allowable total limit. Therefore, special limits are set for the crystalline lens of the eye and localized areas of the skin, hands, and feet to prevent:

1.) Deterministic Effects

2.) Stochastic Effects

3.) Probabilistic Effects

A.) 1 only

B.) 2 only

C.) 3 only

D.) 1, 2, and 3

A.) 1 only

Late deterministic somatic effects (e.g. cataract formation) have a high probability of occurring when entrance radiation doses exceed:

A.) 0.05 Gy

B.) 0.5 Gy

C.) 1 Gy

D.) 2 Gy

D.) 2 Gy

Established organ or tissue weighting factors for calculating the effective dose include a "remainder" that takes into account additional tissues and organs, some of which are the:

1.) Brain

2.) Small Intestine and large intestine

3.) Uterus

A.) 1 and 2 only

B.) 1 and 3 only

C.) 2 and 3 only

D.) 1, 2, and 3

D.) 1, 2, and 3

In International System (SI) units, the cumulative effective dose limit for the whole body of an occupationally exposed person who is 26 years old is:

A.) 26 mSv

B.) 260 mSv

C.) 2600 mSv

D.) 26,000 mSv

B.) 260 mSv

NARM stands for:

A.) Natural atomic radioactive material

B.) Naturally occurring and/or accelerator produced materials

C.) Negligible accelerator produced materials.

D.) Negligible atomic radioactive material.

B.) Naturally occurring and/or accelerator produced material

T or F - The ICRP functions as an enforcement agency for radiation protection purposes.

False

T or F - Future radiation protection standards are expected to continue to be based on risk.

True

T or F - The Radiation Effects Research Foundation is a group run by the government of Japan primarily for the purpose of studying the atomic bomb survivors.

True

T or F - The NRC regulates and inspects x-ray imaging facilities.

False

T or F- In 1991 the ICRP recommended the reduction of the annual EfD limit for occupationally exposed persons from 50 mSv to 20 mSv as a result of new information obtained regarding the Japanese atomic bomb survivors in whom the risk of radiation from the atomic bomb detonations was estimated to be approximately three to four times greater (more damaging) the previously estimated.

True

T or F- Health care facilities that provide imaging services do not need to have an effective radiation safety program.

False

T or F- Effective dose limits may be expressed for whole-body exposure, partial-body exposure, and exposure of individual organs.

True

T or F- Radiation risks are derived from the complete injury caused by radiation exposure.

True

T or F- The Center for Devices and Radiological Health (CDRH) is responsible for credentialing radiographers.

False

T or F- Late deterministic somatic effects may occur months or years after high-level radiation exposure.

True

T 0r F- The ICRP is considered the international authority on the safe use of sources of ionizing radiation.

True

T or F- The NRC publishes rules and regulations in Title X of the Code of Federal Regulations.

True

T or F- The FDA facilities the development and enforcement of regulations pertaining to the control of radiation in the environment.

False

T or F- For high-dose rate fluoroscopic procedures, entrance exposure rates as great as 200 mGya/min or possible.

True

T or F- Health care facilities, such as hospitals, set their own internal action limits.

True

T or F- Because a stochastic event is an all-or-none, random effect, ionizing radiation could induce cancers within a general large population, but it is not possible to determine beforehand which members of that population will develop cancer.

True

T or F- The embryo-fetus is particularly insensitive to radiation exposure.

False

T or F- EfD limits include radiation exposure from natural background radiation and exposure acquired when a worker undergoes medical imaging procedures.

False

T or F- To reduce exposure for pregnant radiation workers and control exposure to the unborn during potentially sensitive periods of gestation, the NCRP now recommends a monthly EqD limit not to exceed 0.5 mSv per month to the embryo-fetus and a limit during the entire pregnancy not to exceed 5.0 mSv after declaration of the pregnancy.

True

T or F- The NRC does not require the name of the RSO on a health care facility's radioactive materials license.

False

T or F- Lifetime survival data possibly appear to indicate that Japanese atomic bomb survivors with moderate radiation exposure of 5 mSv to 50 mSv, the equivalent of 1.5 to 15 years of natural radiation, have a reduced cancer death rate compared with a normally exposed control population.

True

T or F- Employers are not required by law to evaluate their workplace for hazardous agents or to provide training and written information to their employees.

False

T or F- The CDRH falls under the jurisdiction of the FDA.

True

T or F- Radiation hormesis effect is a beneficial consequence of radiation for populations continuously exposed to moderately higher levels of radiation.

True

T or F- All imaging personnel should be familiar with NCRP recommendations.

True