radiation protection: dose limits for exposure to ionizing radiation

EfD

effective dose

D x Wr x Wt

EqD

equivalent dose

D x Wr

effective dose limiting system

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

Efd limiting system is based on

risk of radiation induced malignancies

Efd limiting system limits are documented in the

code of federal regulations

ICRP stands for

international commission on radiological protection

NCRP stands for

national council on radiation protection and measurement

UNSEAR stands for

united nations scientific committee on the effects of atomic radiation

NAS/NRC BEIR stands for

national academy of sciences/ national research council committee on the biological effects of ionizing radiation

ICRP- international commission on radiological protection

-international authority on the safe use of sources of ionizing radiation

-leading international org responsible for providing clear and consistent radiation protection guidance

ICRP recommendations for:

occupational dose limits

public dose limits

NCRP (National Council on Radiation Protection & Measurements)

reviews recommendations formulated by the ICRP and determines how they are incorporated into US radiaiton protection criteria

NCRP formulates...

general recommendations

NCRP publishes...

recommendations in the form of various NCRP reports

NCRP recommendations are...

guidelines for federal and state agencies to follow, they are not an enforcement agency

UNSCEAR assists in

formulation of radiation protection guidelines

UNSCEAR evaluates human and environmental ionizing radiation exposures from a variety of sources, including...

radioactive materials

radiation producing machines

radiation accidents

UNSCEAR derives radiation risk assessments for...

radiation-induced cancer and genetic (hereditary) effects

NAS/NRC BEIR

advisory group that reviews studies of biologic effects of ionizing radiation and risk assessment

NAS/NRC BEIR recommends

for Efd limits and EqD limits

NAS/NRC BEIR studies

groups of people who were either routinely or accidently exposed to ionizing radiation

groups of people the NAS/NRC BEIR study

early radiation workers

atomic bomb victims of Hiroshima and Nagasaki

evacuees from the chernobyl

recommendations for the EfD and EqD limits are made by the:

ICRP

NCRP

UNSCEAR

NAS/NRC BEIR

US regulatory agencies

NRC

agreement states

EPA

FDA

OSHA

NRC stands for

nuclear regulatory commission

EPA stands for

evironmental protection agency

FDA stands for

US food and drug administration

OSHA stands for

occupational safety and health administration

NRC was formerly known as the

atomic energy commission

the NRC is a

federal agnecy that has the authority to control the possession, use, and production of atomic energy in the interest of national security

NRC enforces

radiation protection standards

NRC does not

regulate or inspect xray imaging facilites

NRC supervises

-design work mechanics of nuclear power stations

-production of neclear fuel

-handling of expended fuel

-supervision of hazardous radioactive waste material

NRC controls

the manufacture and use of radioactive isotopes formed in nuclear reactors

NRC writes

rules and regulations which are published in the US code of federal regulations

agreement states agreement with

NRC

agreement states agreements permit the contracting state to undertake the responsibility of

licensing and regulating the use of radioisotopes and certain other radioactive material within that state

agreement states assume

responsibility for enforcing radiation protection regulations through respective heatlh departments

EPA

agency that is responsible for protecting the health of humans and for safegaurding the natural enviorment

EPA oversees ___________, facilitates the development and enforcemnet of....

responsibilities

regulations pertaining to the control of radiaiton in the environment

EPA directs _________ and oversees _________

federal agencies

environmental monitoring

what you are doing with extra of left over medications? Did sharps fo in red bins?

FDA conducts

product radiaiton control programs, regulating design and manufacturing of electronic products

-including diagnostic xray equipment

FDA performs

onsite inspections of xray equipment

OSH is a

monitoring agency in places of employment

OSHA regulates

occupational exposure through the US code of federal regulations

OSHA makes sure

employees right to know about hazards that might present in the workplace

employees should be aware of

hazardous materials, infection agents, ionizing radiaiton, and nonionizing radiation

radiation safety program ensures

adequate safety of pts and radiation workers

NRC mandates that a

radiaition safety committee be established for the facility

having a radiation safety commitee provides

guidance for the safety program and facilitates ongoing operation

RSO- radiation safety officer is selected to

oversee the prgrams daily operation

provide for formal review of program each year

RSO responsibilites

-develops an appropriate radiation saefty program for the facility that follows internationally accepted guidelines for radiation protection

-ensures that facilities operational radiation practices protect all from unnecessary exposure

RSO responsibilities pt 2

-has authority to implement and enforce the policies of the radiaiton saefty program

-reviews and maintains monitoring records for all personnel and must be able to provide counseling for ind. who exceed the allowable limits

according to federal regulations a ________________ must have detailed procedures for handling and disposal for ____________

radioactive materials

to take care of liquid form of radioactive materials you need to

wear gloves, whole body dosimeter, and follow cardinal rules where applicable

to take care of solid form of radioactive materials you must use

long tongs to handle

radiation safety program: radioactive materials

-special packaging and labeling of radioactive materials once contained

-containers are kept for a period of ten half lives

-record is kept for review by regulatory inspectors

radaition control for health and safety act of 1968

protects the public from the hazards of unnecessary radiation exposure resulting from electronic products

-microwave, color tv, xray equipement

center for devices and radiologic health

organization established to conduct ongoing electronic radiation control program

some resonsibility of radiaiton control for health and safety act include

-assessing the biologic effects of ionizing radiation

-evaluating radiaition emissions from electronic products

-conducting research to reduce radiation exposure

who established the principle of ALARA

NCRP

alara concept also known as _______ in accordance with ______________

optimization

ICRP publications

alara concept

the relationship between ionizing radiation and potential risk follows a linear non threshold model

FDA white paper was established in

2010

FDA white paper follows the

premise that each pt should get the right imaging examination, at the right time, with the right dose

FDA indents to take action to

promote safe use of medical imaging devices

support informed clinical decisions

increase pt awareness

consumer pt radiation health and safety act 1981 provides

federal legislation requiring minimal standards for the accreditations of education programs for persons who perform radiologic procedures and the certification of such persons

consumer pt radiation health and safety act 1981 ensures that

medical and dental radiologic practices adhere to rigorous saefty precautions and standards

two main categories of radiation induced responses of serious concern in radiation protection purposes

tissue responses

stochastic (probabilistic) effects

stochastic effects, effects

whose severity dose not depend on the radiation dose, but the proboility of occurence is dose dependent

-cancer, hereditary effects

-result of injury to single cell or a number of cells

tissue reactions

biologic somatic effects of ionizing radiation that can be directly related to the dose recieved

tissue reactions exihibit a

thershold dose

tissue reactions can result after

a long dose of radiation or from long term individual low doses of radiation sustained over years

early tissue reactions

erythema

decreased WBC counts

epilation

acute radiation syndrome

late tissue reactions

cataract formation

fibrosis

organ atrophy

loss of cells

reduced fertility

sterility

stochastic effects

-non thershold

-randomly occurring

-chance probability increases with each radiation exposure

-follows assumption that non minimal safe dose exists

stochastic effect examples

cancer

genetic alterations

effects modern termionolgy defined by

ICRP and NCRP

stochastic and tissue recations

terminology used to describe rad effects (ASRT)

deterministic effects (tissue effects)

deterministic effects (tissue effects)

effects that occur in all individuals who recieve greater than the threshold dose and for which the severity of the effect varies with the dose (NRCP 2003)

what is the current method for controlling risk of biologic damage to radiation workers and the public from radiation exposure?

effective dose limiting system

effective dose limit (EDL)

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

effective dose limiting system calculated values do not include

natural background and medical exposure

to ensure that the hazard to radiation workers is no greater than the hazard to the general working public, NCRP proposes that radiation workers should be prevented from having a total external plus internal cumulative...

EfD in excess of their age in years times 10 mSv

greatest risk for intellectual disability occurred when embryo-fetus was exposed _____________ after conception

8-15 weeks

evidence dose dependent increase in the incidence of severe intellectual disability for fetal doses greater than ______

.4 Sv

EfD limiting systems includes for the

-determination of EqD for tissues and organs

-all radiation vulnerable human organs that can contribute to potential risk

EfD systems

is an attempt to equate the risks of cancer and hereditary effects to the tissues or organs from exposure to ionizing radiation

tissue weighing factor

helps compensate for the varying degrees of sensitivity to different tissues and organs from exposure to ionizing radiation

Wt is recommended by the ______ and adopted by the ______

ICRP

NCRP

Cumulative effective dose (CumEfD)

a radiation workers lifetime effective dose must be limited to his/her age in years times ten

ICRP reports made revision to annual EfD limit for occupationally exposed individuals

recommneded dose of 50 mSv annually to 20 mSv

the revision was a result of

new information obtained from japanese atomic bomb survivors

-doses were estimated to be about 3-4 times greater than previously eastimated

this new change of annual dose has _______ adopted by the NCRP yet

not been

occupationally exposed (NRCP limits)

50 mSv/year

non occupationally exposed (NRCP limits)

1 mSv frequent exposures

5 mSv infrequent exposures

pregnant workers (NRCP limits)

.5 mSv/month

5.0 mSv entire gestration

education/ training (NRCP limits) under 18

1 msv/year

education/ training (NRCP limits) 18 and older

50 mSv (same as workers)

lens of eye (NRCP limits)

150 mSv