2. Copyright of Pickering Enterprises X-Ray Sources Characteristics of X-rays X-ray Safety for Medical Personnel Analytical X-ray Systems Basic x-ray Safety Requirements

3. Copyright of Pickering Enterprises Characteristics of X-rays Produced when high speed electron is slowed down and/or stopped External hazard –Time –Distance –Shielding –Engineered controls –Monitoring –Administrative controls

4. Copyright of Pickering Enterprises What are x-rays? X-rays are produced when accelerated electrons interact with a target, usually a metal absorber, or with a crystalline structure. This method of x-ray production is known as bremsstrahlung. The bremsstrahlung produced is proportional to the square of the energy of the accelerated electrons used to produce it, and is also proportional to the atomic number (Z) of the target (absorber).

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6. Ionizing Radiation

7. Copyright of Pickering Enterprises X-RAY AND GAMMA ( ) RAY PROPERTIES Charge: None Mass: None Velocity: 3 x 10 8 m/s Origin: Rays: Nucleus X Rays: Electron Cloud & Bremsstrahlung

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11. Primary Beam The critical radiation exposure problem with analytical X-ray Can cause localized acute exposure Never intentionally place any part of their body in the primary beam The maximal energy deposition in epithelial tissues Erythema or reddening of the skin can occur when skin is acutely exposed to 300 R (much less than a second) Radiation burns may occur from longer exposures. Scattered Radiation Some of the radiation is scattered out of the primary beam. These radiation fields are less intense than the primary beam They still represent a potential hazard Scattered radiation fields can be measured by the analytical operators with a survey meter. Leakage Some radiation may leak around the rube housing structure. Three Regions of High Exposure Concern

12. Copyright of Pickering Enterprises 1. Primary Beam 2. Scattered Radiation 3. Leakage Rotating Anode Systems: What are the danger areas?

13. Copyright of Pickering Enterprises 1. Primary Beam 2. Scattered Radiation 3. Leakage Sealed Tube Systems: What are the danger areas?

14. Copyright of Pickering Enterprises Sealed Tube/Microfocus Systems: What are the danger areas? 1. Primary Beam 2. Scattered Radiation 3. Leakage

15. Copyright of Pickering Enterprises X-Ray Burns vs. Thermal Burns Most nerve endings are near the surface of the skin High energy x-rays penetrate the outer layer of the skin that contains most of the nerve endings so one does not feel an X-Ray burn until the damage has been done X-rays penetrate to the deeper, basal skin layer, damaging or killing the rapidly dividing germinal cells, that are destined to replace the outer layers

16. Copyright of Pickering Enterprises Exposure Effects 1000 rad - second degree burns 2000 rad - intense swelling within a few hours 3000 rad - completely destroys tissue 400 rad acute whole body exposure is LD 50/30 LD 50/30 - lethal to 50% of population within 30 days if not treated

17. Copyright of Pickering Enterprises Hazards of Exposure to X-rays

18. Copyright of Pickering Enterprises Accident Case Study Case Study - A radiation accident at an industrial accelerator facility Health Physics, Vol. 65, No. 2, August 1992, pp. 131-140. Reproduced by permission. 3MV potential drop accelerator. 40 rad/s inside victim’s shoes, 1300 rad/s to hands. 3 days after exposure Note erythema and swelling 1 month after Note blistering and erythema 2 months after

19. Copyright of Pickering Enterprises Bioeffects- X-rays and Skin Most radiation overexposures from analytical x-ray equipment are to the extremities. For x-rays of about 5-30 keV, irradiation of the fingers or hands does not result in significant damage to blood-forming tissue. At high exposures some general somatic effects to the skin can occur. Very high exposures may necessitate skin grafting or amputation of the affected extremity. Biological effects can be observed at 10 rem in special blood studies. Typically effects are visually observed at 50 to 100 rem.

20. Copyright of Pickering Enterprises Common Cause of Accidents Rushing to complete a a job –Overriding safety features Boredom Fatigue Illness Personal Problems Working on unfamiliar equipment Complacency (Attitude Accumulation) 2 people working 1 job Frustration

21. Copyright of Pickering Enterprises Four Main Causes of Accidents Poor equipment configuration –Ex. Unused beam ports not covered Manipulation of equipment when energized –Adjustment of samples or alignment of cameras when x-ray beam is on Equipment failure –Shutter failure –Warning light failure Inadequate training or violation of procedure –Incorrect use of equipment –Overriding interlocks

22. Copyright of Pickering Enterprises Common Cause of Accidents Rushing to complete a ajob –Overriding safety features Boredom Fatigue Illness Personal Problems Working on unfamiliar equipment Complacency (Attitude Accumulation) 2 people working 1 job

23. Copyright of Pickering Enterprises Preventing Accidents Know location and/or presence of primary and diffracted beams AT ALL TIMES Provide and inspect shielding Do not perform maintenance (without confirming that the tube is not energized) Perform check of safety devices at least once per month Survey unit whenever moved or reconfigured. DON’T PUT YOUR BODY PARTS IN THE BEAM!!

24. Copyright of Pickering Enterprises Exposure Estimates At 5 cm from Tube Port Cu 50 x (40) x (20) 29 = 279 R/sec (7.5) 2 74 Mo 50 x (36) x (20) 42 = 363 R/sec (7.5) 2 74 Ag 50 x (40) x (20) 47 = 452 R/sec (7.5) 2 74 Cu 50 x (50) x (20) 74 = 889 R/sec (7.5) 2 74 Exposure Rate: 50 x(kV) x (mA) Z = R/sec (cm) 2 74 Characteristic Intensity: Proportional to : (kVp - kVc) 1.6

25. Copyright of Pickering Enterprises Radiation Safety Training for X-Ray Diffraction Designated Responsible Operator User Training Operating Procedures/Instructions Engineered Protection Systems Surveillance Programs

26. Copyright of Pickering Enterprises Open Beam XRD Example of an unenclosed (open) x-ray diffractometer (Geology Department). The open x-ray beam of such an instrument can be extremely hazardous, and it is far preferable to enclose the entire x-ray apparatus.

27. Copyright of Pickering Enterprises XRD (tin/polycarbonate enclosure) Properly enclosed and interlocked x-ray diffrac- tometer. The enclosure is made of tin-impregnated polycarbonate. –Leaded glass enclosures are also used. If a panel is opened while the XRD is being used, the interlock should either shut off the x-ray or close the shutter, preventing accidental exposure to personnel.

28. Copyright of Pickering Enterprises AFC8 & Mercury CCD

29. Copyright of Pickering Enterprises AFC7 & Mercury CCD

30. Copyright of Pickering Enterprises RAXIS RAPID

31. Copyright of Pickering Enterprises DMAX RAPID

32. Copyright of Pickering Enterprises MULTIFLEX

33. Copyright of Pickering Enterprises Siemens for powder

34. Copyright of Pickering Enterprises Electron Microscope

35. Copyright of Pickering Enterprises DMAX

36. Copyright of Pickering Enterprises Direct Drive RAXIS/Jupiter

37. Copyright of Pickering Enterprises Belt Drive Rotating Anode AFC6/IV++

38. Copyright of Pickering Enterprises Multiflex

39. Copyright of Pickering Enterprises Service RU200

40. Copyright of Pickering Enterprises Safety Devices Analytical units shall have the following safety devices as required by State Regulations. vUnused ports shall be secure in a manner which will prevent accidental opening. Open beam units shall have a shutter over the port which cannot be opened unless a collimator or coupling has been connected. vSafety interlocks shall not be used to de-activate the X-ray beam except in an emergency or during testing of the interlock system. Warning Devices vAll units with an open beam configuration shall have an easily identified device located near the radiation source housing and labeled what gives a clear, visible indication of the X-ray generation status (on-off) vSafety interlocks shall not be used to de-activate the X-ray beam except in an emergency or during testing of the interlock system.

41. Copyright of Pickering Enterprises Warning Labels vA label which bears the following or similar words shall be placed on the X-ray source housing: CAUTION - HIGH INTENSITY X-RAY BEAM vA label which bears the following or similar wording shall be placed on the control console of each unit near any switch which energizes the source: CAUTION - RADIATION THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED

42. Copyright of Pickering Enterprises Warning Lights vAn easily visible warning light labeled with these or similar words “X- RAY ON” shall be placed near any switch that energizes an X-ray source, and shall be illuminated only when the generator is energized, and have fail-safe characteristics. Shutters vEach port shall be equipped with a shutter that cannot be opened unless a collimator or a coupling device has been connected to the port.

43. Copyright of Pickering Enterprises Radiation Surveys The Radiation Safety Office will perform a survey annually and following major repairs and/or system modifications. This survey will include inspection of all safety systems and a radiation exposure survey. The results of the survey will be kept on file in the Radiation Safety Office. Users of analytical equipment should also routinely perform radiation surveys. The surveys should include monitoring for stray radiation in the immediate vicinity of the X-ray apparatus.

44. Copyright of Pickering Enterprises When the Operator Should Perform a Radiation Survey 1.Upon installation of your instrument. 2.After any major changes in equipment configuration or minor system maintenance to insure that no unanticipated exposure hazards exist. 3.Following any maintenance requiring the disassembly or removal of local components. 4.During the performance of maintenance and alignment procedures. 5.When visual inspection of the local components in the system reveals an abnormal condition.

45. Copyright of Pickering Enterprises Survey Meter Instrumentation Survey should be performed with a portable Geiger-Mueller survey instrument although the results are not necessarily quantitative. If accurate measurements are desired, the instrument should be calibrated with the source of low energy X-rays. Consideration should also be given to possible monitoring errors due to the cross-sectional area of the monitored radiation beam being smaller than the sensitive area of the survey meter.

46. Copyright of Pickering Enterprises General Precautions vOnly Trained personnel shall be permitted to operate an analytical unit. vBe familiar with the procedure to be carried out. vNever expose any part of your body to the primary beam. vTurn the X-ray beam OFF before attempting to make any changes to the experimental set-up (except for beam alignment) vWhile the beam is on DO NOT attempt to handle, manipulate or adjust any object (sample, sample holder, collimator, etc.) which is in the direct beam path (except for beam alignment procedures). vExamine the system carefully for any system modifications or irregularities. vFollow the operating procedures carefully. DO NOT take short cuts! vNever leave the energized system unattended in an area where access in not controlled.

47. Copyright of Pickering Enterprises General Precautions vSurvey the area frequently to evaluate scatter and leakage radiation fields. vNever remove auxiliary shielding without authorization from the owner of the analytical equipment or Radiation Safety Officer. vNever bypass safety circuits, such as interlocks. vReport all unusual occurrences to the owner of the analytical unit for possible corrective actions. vOnly authorized, trained individuals as specified by the unit’s owner and the Radiation Safety Office may repair, align or make modifications to the X-ray apparatus.

48. Copyright of Pickering Enterprises Designated Responsible Operator Authorized by the Health Physics Committee Ensures that only qualified individuals use the equipment Maintains the equipment in compliance with safety requirements

49. Copyright of Pickering Enterprises Limited Open X-ray Systems Accessible area have exposure rates not exceeding 2 mR/hr (any area outside of the barrier or shield routinely occupied by personnel). Maintain a log book of major changes to the system shielding, enclosures, and configurations. Engineered protection system shall be maintained –Failsafe interlocks on removable protective barriers –Exposure rate below 2 mR/hr at 5 cm form any surface –Key control on the production of x-rays –A console power on indicator (must be operational and used) –Warning light adequate to warn anyone present in the room that x- rays are being produced.

50. Copyright of Pickering Enterprises Exposure Potential Fingers are at risk. –Significant injuries have occurred with diffraction x-rays. Large exposures may occur. Skin and eyes may receive exposures.

51. Copyright of Pickering Enterprises General Methods of Protection Time Distance Shielding

52. Copyright of Pickering Enterprises Protective Devices & Procedures Devices –Interlocks –Key control –Shielding Procedures –Operating instructions –Training –Surveys –Exposure monitoring

53. Copyright of Pickering Enterprises How to recognize failures Interlocks don’t work. Radiation is observed during surveys. Unqualified people operating the system. Redness of the skin, normally to the hand. Warning light is not operational.

54. Copyright of Pickering Enterprises Survey procedures & limitations Perform the pre and post operational checks. Record the results. Make sure warning lights are working. Wear your dosimeter. Instruments record low readings.

55. Copyright of Pickering Enterprises Use of radiation dosimetry If you don’t use it, it will not provide useful information. Wear it properly. Don’t wear another persons film badge. If you need additional devices, contact the RSO.

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57. X-ray Safety for Medical Personnel Decrease dose to patient and the operator Time –Determines total dose Voltage –Determines penetration Current –Determines dose rate

58. Copyright of Pickering Enterprises Radiation Exposure from Diagnostic Medical X-ray Examinations in the U.S. (1980) Examination Type Effective Dose Equivalent (mrem) per Examination CT (head and body) 111 Chest 8 Skull 22 Cervical Spine 20 Biliary 189 Lumbar Spine 127 Upper Gastrointestinal 244 Abdomen (kidneys, ureters, bladder) 56 Barium Enema 406 Intravenous Pyelogram 158 Pelvis 44 Hip 83 Extremeties 1 Reference: NCRP Report No. 100, Exposure of the U.S. Population from Diagnostic Medical Radiation (1989).

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60. X-ray Safety for Medical Personnel Filtration removes low-energy x-rays from the primary beam. Collimation limits the beam to a useful area. Compliance testing performed periodically. Registration of sources with regulatory agency.

61. Copyright of Pickering Enterprises Medial X-ray Shielding

62. Copyright of Pickering Enterprises Structural Shielding Design Patient Employee-1 Employee-2 Secondary Barrier Primary Barrier X-ray Tube d sce d pri d sec

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