Radiation Biology Chapter 10

NCRP reports (The National Council on Radiation Protection and Measurements)

Publications that provide the most recent guidelines on radiation protection for the United States

EfD Limiting System

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

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

ICRP- The International Commission on Radiological Protection

International authority on the safe use of sources of ionizing radiation. Responsible for providing clear and consistent radiation guidance through its recommendation for occupational dose limits and public dose limits 

RSO

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

UNSCEAR- United Nations Scientific Committee on the Effects of Atomic Radiation

A united nations committee that evaluates human and environmental ionizing radiation exposures from a variety of sources, including radioactive materials, radiation producing machines, and radiation accidents

Negligible individual dose (NID)

An annual EfD level that provides a low exposure cut-off level that has been determined to be a dose of negligible risk, meaning that a reduction of individual exposure is unnecessary

Annual occupational EfD limit

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

ALARA concept

Optimization for radiation protection

NARM

Naturally occurring and/or accelerator- produced materials

CFR 35.900 of the Code of Federal Regulations

Document that identify the necessary training and experience for an RSO

Annals of ICRP

Scientific journals published by the ICRP 

Action Limits

Established by health care facilities to trigger an investigation to uncover the reason for any abnormal exposure received by individual staff members

Radiation Control for Health and Safety Act of 1968

Public law passed by congress for establishing and overseeing electronic product radiation control including diagnostic x-ray equipment

OSHA- The Occupational Safety and Health Administration

Agency responsible for regulations concerning an employee’s “right to know” about hazards that may be present in the workplace

BEIR reports 

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

FDA

US regulatory agency that conducts an ongoing product radiation control program, regulating the design and manufacture of electronic products, including diagnostic x ray equipment

EfD limit

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

NRC- nuclear regulatory comission

Regulatory agency that has the power to enforce radiation protection standards in the United States

CumEfD limit

Lifetime EfD limit

Tissue reactions

Biologic somatic effects of ionizing radiation that can be directly related to the dose received

Tissue Weighing Factor (Wt) 

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

Radiation- induced malignancy

Cancerous neoplasms caused by exposure to ionizing radiation

Consumer- patient radiation health and safety act of 1981

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

Code of standards for diagnostic x-ray equipment

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

Occupational exposure

1) annual EDL

2) cumulative EDL

50 mSv

10 mSv x age

Occupational exposure

EqD annual limit

• lens of eye

• localized areas of the skin, hands, and feet

150 mSv

500 mSv

Public exposure (annual) 

1) EDL limit, continuous or frequent exposure 

2) EDL, infrequent exposure

1) 1 mSv

2) 5 mSv

Public exposures (annual)

1) EqD limit lens of eye

2) EqD limit localized areas of the skin, hands, and feet 

1) 15 mSv

2) 50 mSv

Public exposures

1) Remedial action for natural sources

a) EfD (excluding radon)

b) exposure to radon and its decay products 

a) greater than 5 mSv

b) greater than 26 J℠ 

Education and training exposures (annual)

1. EDL 

2. EqD limits for organs and tissues

a) lens of the eye

b) localized areas of the skin, hands, and feet

1) 1 mSv

2a) 15 mSv

2b) 50 mSv

Embryo- fetus exposures

1. EqD limit

• monthly

• entire gestation

0.5 mSv

5 mSv

Negligible individual dose (annual)

0.01 mSv