Chapter 10 - Dose Limits for Exposure to Ionizing Radiation

A set of numeric dose limits that are based on calculations for the various risks of cancer and genetic effects to tissues or organs exposed to radiation.

Effective Dose Limiting System (EfD)

EfD is incorporated into ____ __ of the Code of Federal Regulations, part 20.

Title 10

Document that includes rules and regulations of the NRC and fundamental radiation protection standards governing occupational exposure.

Code of Federal Regulations

Concept that is the basis of the Effective Dose Limiting System

radiation exposure and associated risk of radiation-induced malignancy

____ and ____ reports and publications serve as a resource for revised recommendations.

ICRP and NCRP

What are the four radiation protection standards organizations?

ICRP, NCRP, UNSCEAR, and NAS/NRC-BEIR

What does the ICRP stand for?

International Commission on Radiological Protection

What does the NCRP stand for?

National Council in Radiation Protection and Measurements

What does the UNSCEAR stand for?

United Nations Scientific Committee on the Effects of Atomic Radiation

What does the NAS/NRC-BEIR stand for?

National Academy of Sciences/National REsearch Council Committee on the Biological Effects of Ionizing Radiation

The four major radiation protection standards organizations are responsible for evaluating the relationship between what?

radiation EqD and induced biologic effects

____________ are also concerned with formulating risk estimates of somatic and genetic effects of irradiation.

Radiation Protection Standards Organizations

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

ICRP

Nongovernment, non-profit private corporation that reviews recommendations formulated by ICRP and determines the way they are incorporated into U.S. radiation protection criteria.

NCRP

Governmetnal organizations use NCRP recommendations as the ___ ___ for their radiation protection activities.

scientific basis

Derives risk assessments for radiation-induced cancer and genetic effects from research and epidemiologic data.

UNSCEAR

Who has the prominet role in radiation protection guidelines?

UNSCEAR

Advisory group that reviews studies of biologic effects of radiation and risk assessment.

NAS/NRC-BEIR

Limits on radiation exposure are established by ______ or _____ and are based on recommendations of the four agencies.

congressional act or state mandates

__________ are responsible for enforcing the standards after they have been established.

national and state agencies

Responsible for enforcing radiation protecion standards.

Regulatory Agencies

What are the five regulatory agencies?

NRC, EPA, FDA, OSHA, and agreement states

What does NRC stand for?

Nuclear Regulatory Commission

What does EPA stand for?

Environmental Protection Agency

What does FDA stand for?

Food and Drug Administration

What does OSHA stand for?

Occupational Safety and Health Administration

Federal Agency that has the authorit to control the possession, use, and production of atomic energy in the interest of national security.

NRC

Who licenses users of radioactive materials and makes unannounced inspections?

NRC

The NRC as the authority to enter into written contracts with state governments and form ____ ___

Agreement States

____ ____ assumes the responsibility for enforcing radiation protection regulations through their health department.

Agreement States

Is SD an agreement state?

NO

Is responsible for protecting the health of human beings and safeguarding the natural environment.

EPA

Who facilitates the development and enforcement of regulations pertaining to the control of radiation in the environment?

EPA

Regulates the design and manufacture of electronic products, including diagnostic x-ray equipment.

FDA

Compliance with ____ ____ ensures protection of occupationally and nonoccupationally exposed persons from faulty manufacturing.

FDA standards

Monitoring agency in places of employment - predominatently industry.

OSHA

OSHA regulates occupational exposure to radiation through part ___ __ ___ __ of the U.S. Code of FEderal Regulations.

1910 of Title 29

Who is responsible for regulations concerning the employee's "right to know" with regard to hazards in the workplace?

OSHA

Facilities providing imaging services must have an effective and detailed ___ ___ ___ to ensure adequate safety of patients and radiation workers.

radiation safety program

____ must provide the resources necessary (funding, oversee development of plicies and procedures, equipment, ect) for creating and maintaining a radiation safety program.

Administration

NRC mandates that this committee be established for the facility to assist in the deveopment of the radiation safety program.

Radiation Safety Committee

The radiation safety committee provides what?

guidance and facilitates ongoing operation

Oversees the program's daily operation and is invoved with a formal review each year.

Radiation Safety Officer

A Radiation Safety Officer is normally what? (3 occupations)

medical physicist, health physicist, or radiologist

Who is responsible for develping a radiation safety program, enforcing the requirements of the program, and maintaining radiation-monitoring records?

Radiation Safety Officer (RSO)

The required training and experience for RSO is described where?

Code of Federal Regulations

Authority, duties, and responsibilities of the RSO must be established how?

in writing

NRC requires the name of the RSO on ___ ____ to ensure the facility has identified a qualified person and that the person is aware of their designation as RSO.

facility's license

Law to protect the public from hazards of unnecessary radiation exposure resulting from electronic pruducts -- including diagnostic x-ray equipment.

Radiation Control for Health and Safety Act of 1968

What does CDRH stand for?

Center for Devices and Radiological Health

Conducts an ongoing electronic product radiation control program

CDRH

The CDRH works under the jurisdiction of the ___.

FDA

Regulates only the equpment, not the user. States that equipment in use before inception date does not need to be modified or discarded.

Code of Standards for Diagnostic X-Ray Equipment

When is the inception date for the code of standards for diagnostic x-ray equipment?

Aug 1, 1974

Principle form the NCRP that is accepted by all regulatory agencies and is an extremely conservative model

ALARA concept

The ALARA concept bases it's principles on doses that are ________.

As Low As REasonably Achievable

Provides federal legislation requiring the establishment of minimal standards for the accreditation of education programs for persons who perform radiologic procedures and the certification of such persons.

Consumer-Patient Radiation Health and SAfety Act of 1981

The consumer-patient radiation health and safety act of 1981 provides federal legislation requiring the establishment of what?

minimal standards for the accreditation of education programs

NCRP report No. 116 __________ provides the most recent guidance on radiation protection.

Limitation of Exposure to Ionizing Radiation

the NCRP report No. 116 Limitation of Exposure to Ionizing Radiation addresses what?

Risk vs. benefit

Nonstochastic effects are also called?

Deterministic

Stochastic effects are also called?

Probabilistic

can be directly related to dose received and has a threshold dose below which the effect does not normally occur.

nonstochastic effects

For nonstochastic effects, _____ increases as dose increases?

severity of effect

Nonstochastic effects generally occur only after what?

large doses

mutational, nonethreshold, randomly occuring, bilogic somatic changes.

Stochastic effects

For stochastic effects, _________ increases as dose increases.

chance of occurence

Severity of stochastic effects is not ____ _____.

dose dependent

mutations may develop as a result of irradiation of reproductive cells before conception

Mutagenesis

To prevent any clinically important radiation-induced non-stochastic effect from occurring by adhering to dose limits that are beneath what?

threshold levels

Current philosophy is based on the assumption that bilogic damge is ___ ___ to the amout of radiation absorbed - and there is no radiation dose below which a chance of damage does not exist.

directly proportional

The possibility of inducing a radiogenic cancer or genetic defect after irradiation.

Risk

The upper boundary dose of ionizing radiation that results in angligible risk of bodily injury or genetic damage.

effective dose limit

Exposure limits for occupationally exposed persons are associated with risks that are similar to thse encunterd by employees in other industries that are generally considered to be what?

reasonably safe

The NCRP proposes that radiation protection programs be designed to prevent individual workers from having a cumulative EfD of their what?

age in years x 1 rem (10 mSv)

____ _____ _____ compensates for differences in risk from one organ to another.

Tissue Weighting Factor

The NCRP's annual occupational effective dose limit is _____ for the whole body.

5 rem (50 mSv)

The cumulative effective dose limit (CumEfD) or lifetime effective dose must be limited to what?

age in years x 1 rem (age x 10 mSv)

Describes a population or group exposure from low doses of radiation, unit = 1 person-sievert

Collective effective dose

What is the continuous or frequent exposure limit for nonoccupationally exposed individuals?

.1 rem (1 mSv)

What is the infrequent exposure limit for nonoccupationally exposed individuals?

.5 rem (5 mSv)

The monthly equivalent dose limit for pregnant radiation workers?

.5 msv (.05 rem)

What is the entire pregnancy dose limit for pregnant radiation workers?

.5 rem

What is the limit for individuals under the age of 18 (education and training purposes)

.1 rem

Facilities set their own ____ ____ to avoid the chance that personnel are exposed to their EfD limits?

action limits

Action limits are typically set at __ of the limit.

1/10

Personnel ___ readings are monitored for dose limits.

dosimeter

The theory that there is a beneficial consequence of radiation for populations continuously exposed to moderately high levels of radiation

Radiation Hormesis

What is the dose annual limit for the lens of the eye in occupational workers?

15 rem (150 mSv)

What is the dose annual limit for localized areas of the skin, hands, and feet of occupational workers?

50 rem (500 mSv)

What is the dose limit for the lens of eye for the public?

1.5 rem (15 mSv)

What is the dose limit for the localized areas of the skin, hands, and feet for the public?

5 rem (50 mSv)

What is the effective dose (excluding radon) for remedial action for natural sources?

>.5 rem (5 mSv)

What is the remedial action to exposure to radon and its decay products?

>2 WLM

What is the dose limit for the lens of the eye in education and training exposures?

1.5 rem (15 mSv)

What is the dose limit for localized areas of the skin, hands, and feet in education and training procedures?

5 rem

What is the negligible individual dose limit?

.001 rem (.01 mSv)

Loss of hair

epilation

the type of effective dose that must be limited to a radiation worker's age in years times 10mSv (years x 1 rem)

lifetime

city in japan on which an atomic bomb was dropped

hiroshima