Ch 10 Dose limits
Page 5: Health Policy
Defining Health Policy
Health policies include decisions, plans, and actions to achieve specific healthcare goals.
Composed of statutes and regulations.
Page 6: Health Physics
Focus of Health Physics
Health physics is concerned with providing occupational radiation protection.
Aims to minimize radiation dose to the public.
Page 7: Involvement in Health Policy
Activism in Health Policy
Encourage active participation in state and national societies to influence health policy.
voting, running for office, going to meetings
Page 8: Organizations for Radiation Protection Standards
Organizations
International Commission on Radiological Protection (ICRP)
National Council on Radiation Protection and Measurements (NCRP)
United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)
NAS/NRC Committee on Biological Effects of Ionizing Radiation (BEIR)
Page 9: Summary of Functions of Standards Organizations
Function of Each Organization
ICRP
Evaluates biologic effects of radiation; provides guidance on dose limits.
NCRP
Reviews ICRP regulations and formulates U.S. radiation protection criteria.
UNSCEAR
Evaluates human/environmental exposure to ionizing radiation.
NAS/NRC-BEIR
Reviews studies on biologic effects and assesses risks, providing information for evaluation.
Page 10: NCRP
Role of NCRP
Publishes radiation protection recommendations; not an enforcement agency.
Radiation exposure limits established by Congress, referencing NCRP Report No. 116.
Page 11: U.S. & State Regulatory Agencies
Key Agencies
Nuclear Regulatory Commission (NRC)
Agreement States
Environmental Protection Agency (EPA)
Food and Drug Administration (FDA)
Center for Devices and Radiological Health (CDRH)
Occupational Safety and Health Administration (OSHA)
Ohio Department of Health (ODH)
Page 12: Function of U.S. Regulatory Agencies
Agency Functions
NRC
Oversees nuclear energy industry, enforcing radiation protection standards.
Agreement States
States work with NRC to regulate radiation use, enforcing protection regulations.
EPA
Develops regulations for environmental radiation control.
FDA
Regulates electronic product safety; monitors radiation exposure in medical devices.
OSHA
Monitors radiation exposure in workplaces.
Page 13: NRC Definition and Functionality
NRC Overview
Regulates and licenses to protect radiation workers’ health.
Functions as an enforcement agency transferring authority to states.
Page 14: Agreement States
Definition
States entering agreements with NRC to enforce radiation regulation through health departments.
Non-agreement states will coordinate with NRC for facility inspections.
Page 15: State Regulations Overview
State Regulatory Legislation
Legend detailing states according to their regulation of radiologic disciplines.
Highlights three levels of state involvement in regulating radiology.
Page 16: Environmental Protection Agency (EPA)
EPA Role
Responsible for controlling radiation in the environment.
Page 17: Food and Drug Administration (FDA)
FDA Responsibilities
Regulates design/manufacture of electronic products, requiring incident reporting of safety breaches.
Promotes safety in Computed Radiography (CR) and Digital Radiography (DR).
Page 18: Center for Devices and Radiological Health (CDRH)
CDRH Function
Part of FDA.
Evaluates population exposure to imaging techniques; regulates x-ray equipment performance.
Page 19: Radiation Control for Health and Safety Act of 1968
Act Overview
Protects public from hazards of radiation in products, setting standards for x-ray equipment manufacturing.
Page 20: Consumer-Patient Radiation Health and Safety Act of 1981
Act Provisions
Establishes minimum educational standards and certification for radiologic technologists.
Ensures safety standards for medical and dental procedures related to radiation.
Page 21: Radiation Safety Program
Overview of Safety Programs
Facilities must maintain effective radiation safety programs.
NRC mandates formation of a Radiation Safety Committee (RSC) and appoints a qualified RSO.
Page 22: Role of Radiation Safety Officer (RSO)
RSO Responsibilities
Oversees RSC operations and ensures compliance with guidelines.
Develops a safety program and maintains records.
Page 23: RSO Qualifications
Qualifications Required
Must be certified by NRC with relevant experience and be an authorized user of ionizing radiation.
Page 24: Code of Standards for Diagnostic X-ray Equipment
Standards Overview (1974)
Standards include positive beam limitation, appropriate filtration, reproducibility, visual indicators, and manual timers.
Page 25: ALARA Principle
ALARA Introduction
Established in 1954 – encourages minimizing radiation exposure.
Endorsed by regulatory agencies to ensure safety in medical imaging.
Page 26: ALARA and Risk Assessment
Risk Assessment Model
Presumes a conservative approach to ionizing radiation effects and promotes caution over optimism in risk estimations.
Page 27: Goals for Radiation Protection
Radiation Protection Goals by NCRP
To prevent serious radiation-induced conditions and reduce stochastic effects in relation to benefits from exposures.
Page 28: Categories of Radiation-Induced Responses
Main Categories
Non-stochastic Effects: Occur above a certain dose threshold.
Stochastic Effects: Probability increases with dose; all exposure is considered hazardous.
Page 29: Deterministic (Non-stochastic) Effects
Characteristics
Effects are dose-related and have a threshold; severity increases with dose.
Typically not seen in diagnostic x-ray.
Page 30: Deterministic Effects Overview
Additional Notes
Exhibit a non-linear threshold relationship; severity does not proportionally align with dose.
Page 31: Stochastic Effects
Characteristics
Probabilistic outcomes related to exposure; risks increase with higher doses.
Non-threshold effects include cancer and genetic changes.
Page 32: Current Radiation Protection Philosophy
Philosophy Overview
Linear non-threshold relationship exists; all doses carry some risk.
Justification for exposure relies on balancing benefits against potential risks.
Page 33: Minimizing Risk of Ionizing Radiation
Goals of Risk Mitigation
Limit exposure of public and workers; regulate through defined EfD and EqD limits.
Page 34: Effective Dose Limiting System
Concept Overview
Analyzes risks associated with radiation exposure; advocates for adherence to established limits.
Page 35: System Focus
Focus of Limiting System
Establishes an upper boundary for ionizing radiation exposure, ensuring negligible risk to health.
Page 36: Occupational Exposure Limits
Recommendations
Limits integrate an upper boundary reflective of risks similar to safer industries.
Page 37: Detailed Occupational Limits
Age-Based Recommendations
NCRP suggests keeping lifetime EfD below 10 mSv multiplied by age in years.
Page 38: Annual Occupational Dose Limits
Proposed Changes
Currently set at 50 mSv; under review to potentially lower to 20 mSv based on new data.
Page 39: Non-Occupational Exposure Limits
Annual Limits Overview
Separate limits for non-occupational exposure (5 mSv and 1 mSv yearly).
Page 40: Summary Table of Dose Limits
Dose Limits Overview
Includes comprehensive limits for technologists, students, and general public defined in a table format.
Page 41: Summary for Partial Body Exposure Limits
Key Limits
Detailed exposure limits for specific body areas including the lens of the eye and skin, with memorization aid emphasized for exams.
Page 42: Action Limits and Responses
Institutional Protocols
Facilities should investigate unusual dosimeter readings; action limits established by RSO.
Page 43: Radiation Hormesis
Concept Overview
Suggests small radiation exposures could potentially be beneficial; a cautious approach is still recommended.