Dental X-Ray Safety Training

1. Dental X-Ray Safety Training Radiation Safety Program Safety, Health, Environment & Risk Management (SHERM) 713-500-5840

2. THE SHERM MISSION Safety, Health, Environment and Risk Management’s (SHERM) mission is to work in conjunction with the UTHSC-H community to ensure that education, research, and health care services activities take place in conditions that are optimally safe and healthy for all student, faculty, staff, visitors, surrounding community and the general public. Put simply, we exist to help people go home as healthy and safe as they arrived.

3. Outline • Fundamentals of radiation • How x-rays are produced • Annual background exposure • How to minimize your radiation exposure • Instructions for the radiation monitoring program • Potential biological effects from radiation exposure • Operating and Safety Procedures • Access to applicable dental radiation regulations • Radiation Safety contact information

4. What is radiation? • Emission of energy in the form of particles (e.g. beta) or waves (e.g. x-rays) • “Ionizing” radiation has enough energy to remove an orbital electron and produce ions.

5. Radiation Spectrum Radio Microwave Infrared Visible Ultraviolet X-ray Gamma Ray 103 10-2 10-5 .5 x 10-6 10-8 10-10 10-12 Wavelength (meters) Electromagnetic radiation travels through space in the form of waves. Waves of all types have an associated wavelength and frequency. Radio waves have the longest while gamma rays have the shortest wavelength.

6. Wilhelm Roentgen Discovers X-rays • November 8, 1895 • While studying cathode ray tubes, he noticed that the fluorescence occurred in a cathode ray tube even when shielded from outside light • Discovery instantly revolutionized physics and medicine

7. X-Ray Tube Tungsten Target

8. X-ray Tube Anatomy • X-rays are produced by energy conversion when a fast moving stream of electrons is suddenly slowed down in the target (e.g. tungsten) anode of the x-ray tube.

9. Natural and Manmade “Background” Radiation National Annual Average Exposure is 625 mrem Note: Medical procedures are not occupational but exposures as a patient.

10. Radon • Largest contributor to background radiation in the U.S. • Noble gas • not readily incorporated into tissues • deposited to the lungs via nuclides attaching to aerosols in the air • Seeps into basements and foundations of homes and buildings • location, building materials, and soil determine radon exposure

11. X-ray Output • The dose to the patient may change by varying the parameters of the x-ray machine such as: • Total exposure time • Tube current (mAs) {Controls the # of x-rays} • Kilovolt peak (kVp) • Beam shaping • Collimation

12. Minimize Exposures by • Combining the use of • Least Time • Greatest distance • Appropriate shielding In order to maintain doses = As Low As Reasonably Achievable

13. ALARA Techniques • Minimize the time spent in unshielded environments while the x-ray beam is on • Avoid anyone beyond the patient being in the area while x-ray beam is on • Stand at least 6 feet away from the dental x-ray machine • Standing 6ft away verses 1 ft away reduces the exposure by 1/36

14. ALARA Techniques • X-rays are easily shielded by a layer of dense material, like lead. • Exam room walls may be shielded to protect the public areas. • Protective aprons, leaded walls and leaded glass barriers in diagnostic radiology often block most (~90% - 99%) of the radiation. Tissue Plexiglas Thin Lead Thick Lead

15. Protective Equipment Personnel Protective Apparel Lead aprons, gloves, thyroid shields Visual and tactile examination of leaded aprons is required annually

16. Occupational Exposure Any worker who receives radiation exposure while performing a job or task. The worker is required to wear dosimetry if their job tasks produce high enough exposures that they are “likely” to exceed 10% of the occupational dose limits.

17. Occupationally Exposed Worker: rem mrem Whole body 5 5000 Eye 15 15,000 Shallow 50 50,000 Minor 0.5 500 Pregnant Worker 0.5* 500* *in 9 months General Public: 100 mrem/year or 2 mrem/hour Annual Radiation Exposure Limits

18. Dental X-ray Regulations for Monitoring Occupational Exposures • 25 TAC §289.232(d)(6) – No individual monitoring shall be required for personnel operating only dental radiation machines for dental diagnostic purposes • UTHSC-H, EH&S will monitor dental x-ray operators who request dosimetry. • Quarterly change out is typical at UTHSC-H for personnel operating dental x-ray machines

19. How to Obtain a Badge… Fill out form (RS-03) available online or by contacting Radiation Safety Program http://www.uth.tmc.edu/safety/radsafety/rs03.htm

20. http://www.uth.tmc.edu/safety/radsafety

21. Proper Badge Locations At the collar & outside any lead apron Wear any specially assigned abdomen badge at the waist underany protective apron

22. Declared Pregnancy • When you contact RSP regarding your pregnancy, RSP will schedule a confidential meeting to: • Review the risks associated with prenatal exposures and methods to minimize risks • Review previous personnel monitoring results • Review exposure limits • Discuss the NRC Regulatory Guide 8.13 • Provide an opportunity for questions • Provide additional monitoring if appropriate • Assist you in completing the written declaration

23. Declared Pregnancy • Program to assess, monitor, define and minimize exposures to the developing fetus. • It is the individual’s decision to contact the Radiation Safety Program (RSP) and provide a written declaration of pregnancy for the lower limit to be applied. • Limit is  500 mrem per gestation period • With a recommendation of a 50 mrem limit per month • In rare cases, job duties or assignments may be re-evaluatedand changed. http://www.nrc.gov/reading-rm/doc-collections/reg-guides/ occupational-health/active/8-13/index.html

24. Contact the RSP at 713-500-5840 or CYF G.102 to discuss pregnancy and radiation. We will assist you in completing the shown (RS-14) form. http://www.uth.tmc.edu/safety/radsafety/ Pregnant%20Employee's%20Guide%20to%20Radiation.html

25. Potential Biological Effects? Radiation Misconceptions. . . . . .

26. Biological Damage • Radiation may… • Deposit Energy in Body • Cause DNA Damage • Create Ionizations in Body • Leading to Free Radicals • Which may Lead to Biological Damage • Radiation is a weak carcinogen (chronic effect) • A dose of 1,000mrem increases your risk in cancer by ≈ 0.04% • Acute effects (e.g. erythema) have a threshold and the dose increases the severity of effect

27. Biological Effects

28. Paperwork, paperwork . . . . . . . . For the protection of patients & workers, there are requirements • Federal regulations • State regulations • UTHSCH Standard Operating Procedures • Equipment registration • Equipment Calibrations • Hmmm…...

29. DSHS Requirements • Registration for all machines • If not digital x-ray unit • Log of developing chemical replacement • Darkroom tests (stray light) • Annual lead apron tests for integrity • Receipt/disposal records of equipment • Record of maintenance • Calibration of machines by Licensed Medical Physicist • Review of Standard Operating Procedures • Documented training • Patient log

30. Radiation Control, Texas Department of State Health Services • Regulations are available at: • http://www.dshs.state.tx.us/radiation/rules.shtm • 25 Texas Administrative Code (TAC) • §289.231 – X-ray Safety (General) • §289.203 – Notices to Workers • §289.232 – Dental Radiography

31. Dental Regulations

32. General Machine Requirements • Images must have dentist orders • Minimum distance is 6 feet from patient unless standing behind protective barrier • Technique chart • Exclude unnecessary personnel from area • Keep out of direct beam path • Use shielding prudently (0.25 mm of lead) • Minimize retakes • Operators must be credentialed

33. Postings for Radiography Rooms If you are pregnant or suspect you are, please inform the technologist BEFORE x-rays are taken. Thank you.

35. Overexposure Data Background • Texas Department of State Health Services’ Radiation Control (DSHS-RC) (formerly known as Texas Depart of Health’s Bureau of Radiation Control (TDH-BRC)) is the designated state agency for issues involving radiation in Texas • An essential function of the DSHS-RC is responding to incidents and complaints • Records of such events have been recorded in text format since 1956 • This data is much more thorough than any other state or federal government agency, but is not in a format that is analyzable • Previous work performed by Dr. Robert Emery and Dr. Mike Charlton examined, classified, and defined various events that occurred from 1988-1997

36. Definition of Overexposure in Texas

37. Reported Radiation Incidents in Texas, 1956-2000 (n=6,102) (n=6,102)

38. Overexposure Incidents in Texas by Total Dose, 1956-2000 Only 2% of the overexposures in Texas from 1956 to 2000 have been high enough to see acute clinical effects

39. Initial Overexposure Conclusions • Near equal prevalence of overexposures in medical and industrial settings • Significant decreases in overexposure incidents • Early 80’s, likely related to oil and gas exploration activity in Texas • After 1994, likely due to change in regulations • Within the largest category of events in Texas from 1956-2000, the occurrence of non-stochastic events was rare.

40. For Assistance or More Information… • Operating & Safety Procedures for Use of Radiation in Dental Branch Clinics • For current version contact Ms. Adkisson’s office • Radiation Safety Website http://www.uth.tmc.edu/safety/radiation_safety.html • Forms is the repository for standard forms (e.g., dosimetry, training & experience) • Policies lists the basic radiation safety policies • Manuals – UTHSC-H Radiation Safety Manual • Radiation Safety Office Phone Number: 713 500 5840 In an Emergency (call): (713) 500 4357 (HELP)