Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Need for a Regulatory program

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 2 Module 1-2 Objective To understand the role of regulatory program in providing adequate safety in the use of radiation sources in medical, industrial, agriculture, research etc. practices

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 3 Module 1-2 Contents Beneficial uses of ionizing radiation. Harmful effects due to the lack of and/or effectiveness of an adequate and appropriate radiation safety program. Consequences of radiological accidents and lessons learned.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 4 Module 1-2 science; Uses of Radiation Radiation Sources have been used to benefit society in:- research; industry; medicine; environmental protection; and a number of academic and commercial fields.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 5 Module 1-2 Regardless of the beneficial uses, many people are afraid of radiation and the potentially harmful effects. The public is concerned about accidents that could affect their health and everyday lives. Uses of Radiation (cont)

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 6 Module 1-2 “Acceptance by society of risks associated with radiation is conditional on the benefits to be gained.” Basic Safety Standards (BSS) Balancing risks and benefits is the key issue. Risk versus Benefit

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 7 Module 1-2 The Main Uses of Radiation Sources

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 8 Module 1-2 The primary purpose of a regulatory program is to provide an appropriate standard of protection and safety for humans without unduly limiting the benefits of the practice giving rise to the exposure. Purpose of a Regulatory System

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 9 Module 1-2 prevent the occurrence of deterministic effects in individuals by ensuring doses are kept below the relevant threshold; Purpose of a Regulatory System (cont) Effective defences against radiological hazards from sources should be established and maintained to:- ensure that all reasonable steps are taken to minimize the occurrence of stochastic effects in the population.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 10 Module 1-2 Deterministic effects There is a threshold dose below which no short term effect is observed. Above this threshold the severity of the effect increases with dose. eg burns, nausea. Deterministic and Stochastic Effects Stochastic effects There is no established threshold dose. The probability of a long term effect increases with dose. eg the induction of cancer.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 11 Module 1-2 Early Observed Effects of Ionizing Radiation

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 12 Module 1-2 Balance benefits/costs and detriments through:- justification; Basic Principles Implement the regulatory requirements through:- optimization; limitation. prevention; Proper organization and management mitigation.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 13 Module 1-2 The justification of a practice implies doing more good than harm. Basic Principles (cont) The optimization of protection implies maximizing the margin of good over harm (ALARA). The use of recognized dose limits implies an adequate standard of protection even for the most highly exposed individuals.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 14 Module 1-2 The Standards are intended:-: to place requirements on legal persons authorized to conduct practices causing radiation exposure, and to provide for intervention in order to reduce existing exposures. Restriction of Risks The risks associated with radiation exposure must be minimized and workers and the public protected by applying basic radiation safety standards.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 15 Module 1-2 The implementation of the Standards requires that a Regulatory Authority be established by the Government to regulate the introduction and conduct of any practice involving sources of radiation. Implementation of the Standards The Regulatory Authority should implement a national regulatory program for the control of radiation sources.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 16 Module 1-2 in industrial irradiators; Lessons to be Learned Accidents resulting in fatalities and injuries have been reported:- industrial radiography; radiotherapy; and as the result of lost or abandoned sources etc.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 17 Module 1-2 Reports on Lessons from Major Accidents

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 18 Module 1-2 Individual accident reports Individual Accident Reports

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 19 Module 1-2 An inadequate regulatory framework in respect of:- authorizations; inspections; enforcement. Causes of Accidents Poor user safety culture in areas such as:- management; quality control; training and qualifications of personnel.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 20 Module 1-2 Accidents with Irradiators

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 21 Module 1-2 Accidents with Irradiators (accelerators)

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 22 Module 1-2 Accidents with Irradiators (gamma)

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 23 Module 1-2 Accidents with Radiotherapy Patients

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 24 Module 1-2 Number of Patients involved in Radiotherapy Accidents

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 25 Module 1-2 Generally involve the public; and workers who are not involved with the normal use of the sources Accidents due to loss of control of sources

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 26 Module 1-2 Deaths due to loss of control of sources

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 27 Module 1-2 Deterministic Effects in Diagnostic Radiology Skin damage months after this 40 year old patient underwent 2 coronary angiograms and a coronary angioplasty in the one day. Estimated skin dose > 20 Gy. Source: Radiation Induced Skin Injuries from Fluoroscopy Thomas B Shope 1995 USFDA Center for Devices and Radiological Health

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 28 Module 1-2 Deterministic skin injuries reported to USFDA

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 29 Module 1-2 There was an excessive and/or inappropriate use of the high dose rate mode. The filtration of the x-ray beam was inadequate. A fixed beam geometry was used (radiation entering through the same skin surface all the time). There was an undetected malfunction of the automatic exposure control system. Diagnostic Radiology Incidents - Summary of Lessons The x-ray tube was too close to the patient.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 30 Module 1-2 Severe deterministic effects; e.g. death, loss of limbs, erythema, acute radiation syndrome. General Consequences of Accidents Contamination of the environment. Social impact. Economic impact.

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 31 Module 1-2 maintenance; control. Safe operation requires: training; Safe use of Radiation Sources Radiation Sources: are widely used; SAFETY CULTURE } provide substantial benefits; but can cause harmful effects (injury or death).

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 32 Module 1-2 the RISKS BENEFITS should outweigh Safe use of Radiation Sources

Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Slide 33 Module 1-2 International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115, IAEA, Vienna (1996). Organization and Implementation of a National Regulatory Infrastructure Governing Protection against Ionizing Radiation and the Safety of Radiation Sources, IAEA-TECDOC-1067, Vienna (1999). Lessons learned from accidents in radiotherapy, industrial irradiation facilities and industrial radiography, (reports in) IAEA Safety Reports Series. IAEA, Accident reports (various). References