Chapter 10 Dose Limits for Exposure to Ionizing Radiation

what does UNSCEAR do?

Evaluates human and environmental ionizing radiation exposure and makes radiation risk assessments

what does the NRC do?

enforces radiation protection standards. controls the manufacture and use of radioactive isotopes

ALARA acronym stands for?

as low as reasonably achievable

what are tissue reactions?

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

what is the EfD limiting system?

current method for controlling risk of biological damage to radiation workers and the public from radiation exposure

upper boundary dose

NCRP recommends radiation workers should be prevented from having a total external plus internal cumulative EfD exceeding:

their age x 10 mSv

CumEfD limit occupationally for full body exposure

50 mSv

explain concept of radiation hormesis

concept that there is a beneficial aspect or result to groups of individuals from continuing exposure to small amounts of radiation

describe the effective dose limiting system

numeric dose limits based on various risks of cancer and genetic effects to tissues or organs exposed to radiation

based on risk of radiation induced malignancies

EfD

The effective dose (Sv)- the most effective calculation to determine radiation received.
Formula: D x WR x WT
(dose x radiation weighting factor x tissue weighting factor)

EqD

the equivalent dose (Sv)
formula: D x WR (dose x radiation weighting factor)

what are the four main recommending groups?

ICRP
NCRP
UNSEAR
NAS/NRC-BEIR

What does NAS/NRC-BEIR stand for

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

what does the NCRP do?

reviews recommendations from the ICRP and incorporates ideas into US criteria. produces guidelines and RECOMMENDATIONS for federal and state agencies to follow

what does NAS/NRC-BEIR do?

reviews studies of biological effects of ionizing radiation and risk assessment. RECOMMENDS for EfD and EqD limits

studies groups of people such as: early radiation workers, atomic bomb victims, evacuees from chernobyl

responsibilities of the radiation safety officer (RSO)

monitor dosimeter badges and radiation records for employees, provide counseling when the action limit is exceeded for an employee, ensures facilities practices protect all, develops program to follow internationally accepted guidelines

purpose of ALARA

to protect those exposed to ionizing radiation, keeping patient dose as low as possible while still maintaining quality diagnostic images

ORP stands for?

optimization for radiation protection

who established the principle of ALARA or ORP

NCRP (national commission on radiation protection and measurements)

what is the FDA "white paper"

follows the premise that each patient should get the right imaging, at the right time, with the right dose

Consumer-Patient Radiation Health and Safety Act of 1981

In wisconsin, exposures cannot be taken without certification

what are the 2 main categories of radiation induced responses?

tissue responses, stochastic effects

what are examples of late tissue reactions?

cataract formation, fibrosis, organ atrophy, temporary sterility, infertility

CumEfD limit:

radiation worker's lifetime EfD should not exceed their age x 10 mSv

what is the occupational EfD limit annually?

50 mSv

what is the occupational EqD limit for the skin, hands, and feet?

500 mSv

explain ALARA/ORP

as low as reasonably achievable/optimization for radiation protection
purpose of protecting patients by reducing pt dose to smallest amount possible while still maintaining quality diagnostic images

annual occupational EqD limit for the lens of the eye

150 mSv

EfD limit for infrequent exposures for the general public

5 mSv

educational and training EfD limit for those under age 18

1 mSv

educational and training EfD limit for those over 18

50 mSv

describe the effective dose limit

A dose that is not expected to produce significant effects - upper boundary dose to prevent those from reaching it

Effective Dose Limiting System

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

what does ICRP stand for?

International Commission on Radiological Protection

what does NCRP stand for?

National Council on Radiation Protection and Measurements

what does UNSEAR stand for?

united nations scientific committee on the effects of atomic radiation

what does the ICRP do?

provides RECOMMENDATIONS for occupational dose limits and public dose limits

who recommends for the EfD and EqD limits?

ICRP, NCRP, UNSCEAR, NAS/NRC-BEIR

who are the regulatory groups?

nuclear regulatory agency (NRA), agreement states, environmental protection agency (EPA), US Food and Drug Administration (FDA), Occupational safety and health administration (OSHA)

what does NRC stand for?

nuclear regulatory commission

what do the agreement states do?

are in contract with the NRC and enforce radiation protection regulations through their respective health departments.

what is the EPA

environmental protection agency

what does the EPA do?

enforcement of regulations pertaining to the control of radiation in the environment
-ex. RADON, pharmaceutical waste bins for barium

what is the FDA?

US Food and Drug administration

what does the FDA do?

conducts product radiation control programs, regulating design and manufacturing of electronic products
ONSITE INSPECTIONS OF X-RAY EQUIPMENT

what is OSHA?

occupational safety and health administration

what does OSHA do?

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

who are the regulatory agencies?

NRC, agreement states, OSHA, EPA, FDA

what is the purpose of the Radiation safety program?

to ensure safety of patient's and occupational workers at each facility

who mandates the requirement of a radiation safety program?

NRC

who oversees the radiation safety program at a facility?

the radiation safety officer (RSO)

Radiation Control for Health and Safety Act of 1968

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

what category of radiation induced responses have a threshold or can be determined ?

tissue responses

what category of radiation induced responses are probable to happen at a certain dose?

stochastic effects

what are examples of early tissue reactions?

erythema, epilation, decreased WBC count, acute radiation syndrome

what are stochastic effects?

randomly occurring biological effects caused by radiation- follows assumption that no dose is safe

the ICRP adopted the idea that occupational dose should be reduced from 50 mSv to ___???

20 mSv

does the NCRP follow the ICRP's idea of reducing annual dose limit from 50 mSv to 20 mSv?

no

what is the occupational CumEfD limit?

worker's age x 10 mSv

what is the occupational EqD limit for lens of eye?

150 mSv

differences between tissue responses and stochastic effects

stochastic effects are probable to occur with a certain dose of ionizing radiation while tissue responses have a threshold dose where they will occur at a certain dose

annual occupational EqD limit for the skin, hands, feet

500 mSv

EfD limit for continuous exposures for the general public

1 mSv