RADIATION SAFETY IN-SERVICE

1 General Information about Radiation Often depicted by books, movies and news media as mysterious, deadly force. In truth: _ Nothing mysterious at all _ Radiation has been studied for over 100 years _ Detection, measurement and radiation control are extremely common events _ The more the public understands, the less frightening it becomes _ A very beneficial diagnostic tool	2 Radiation Units of Measurement: _Roentgen: Unit of radiation exposure in (R) air _Rad: Energy absorbed per gram of material/tissue _Rem: Biological effect of a rad
3 Radiation Units _ Although the 3 units of radiation described previously are entirely different, for the energy ranges used in Nuclear Medicine, they are approximately equal. 1R ~= 1 Rad ~=1Rem _ The standard unit of radiation protection is usually millirems (mrem). 1 mrem = 1/1000 of a Rem 1 Rem = 1000 mrem	4 Background Radiation _ Definition: Relatively constant low-level radiation from environmental sources such as the earth (or building materials), cosmic rays, and naturally occurring radionuclide found in the body. _ Level of background radiation will vary depending upon location, altitude and the amount of natural radioactive material in the ground. _ Highest known background levels recorded in mountains of South America - 1000 millirem (1 Rem).
5 Background Radiation _No known proven carcinogenic effects from radiation levels in the order of magnitude comparable to background radiation. _ Typically, exposures received from diagnostic procedures fall well within background levels.	6 Typical Background Radiation Levels _ New York City ~ 300 mRem//year _ Denver ~ 500 mRem//year _ Grand Central Station > 500 mRem//year _ Andes Mountains ~ 1000 mRem//year or 1 Rem//year _ One banana ~ 0.1 mRem _ Flight from LA to London ~ 5 mRem
7. Personnel Monitoring _ Procedure instituted to estimate the amount of radiation received by individuals who work around radiation. It simply measures the amount of radiation to which one was exposed. _ The monitor offers no protection against radiation exposure.	8 Personnel Monitoring _ Required when _ An individual is likely to receive more than 1/10th the yearly occupational dose limit (i.e. whole body limit: 1/10th of 5000mRem = 500 mRem) _ An individual handles radioactive material _ An individual works in a high radiation area _ Therefore, it is usually not necessary to monitor Nuclear Medicine secretaries, file clerks and operating room personnel. _ Monitors are typically worn on the collar and positioned outside the protective apron during fluoroscopic procedures. _ Pregnant workers are to wear the badge at waist level to monitor fetal exposure.
9 Occupational Dose Limits _ Whole Body 5000 mrem//yr _ Lens off Eye 15,,000mrrem//yr _ Extremities 50,,000 mrem//yr _ Fetus 500 mrem for entire gestational period ((50 mrem//month))	10 Typical Exposure Levels Encountered in Normal Occupational Situations: _ Nuclear Medicine Tech -- < 500 mrem//year _ Radiologic Technologist -- ≈ 100 mrem//year _ Portable Chest X--Ray -- ≈ 0..02 mR @ 1 meter exposure _ Portable abdomen -- ≈ 0..5 mR@ 1 meter exposure _ Conventional fluoro -- ≈ 2 mR//min @1meter _ Special Procedure -- ≈ 10 mR//min @ 1meter
11 Exposure from Nuclear Medicine Patients _ Patients injected with radiopharmaceuticals emit relatively small amounts of radiation. _ The activity for diagnostic procedures is extremely low and poses no real danger. _ Typical Nuclear Medicine exposures _ Tc99m MIBI 27mCi <0.2mR/hr at 1meter _ Tl201 2.7mCi <0.05mR/hr at 1 meter _ Tc99m MDP 24mCi <0.1mR/hr at 1 meter Adapted from the Journal of Nuclear Medicine Technology Volume 30, Number 1, March 2002, pg 29	12 General Precautions for Occupational Workers _ The three cardinal rules for radiation safety are: • Time •Distance • Shielding
13 Time _ Minimize the time spent near packages of radioactive materials.	14 Distance _ Distance offers great protection for any kind of radiation. _ Radiation exposure follows the inverse square law: Move twice as far, the radiation is reduced by a factor of 4. _ Stand next to the source of radiation, as little as possible. _ Standing six feet away from an exam table will significantly reduce your radiation exposure.
15 Shielding Alpha Particles Stopped by a sheet of paper Beta Particles Stopped by a layer of clothing or less than an inch of a substance (e.g. plastic) Gamma Rays Stopped by inches to feet of Concrete or less than an inch of lead	16 General Nuclear Medicine Guidelines _ Only physicians listed on the license may order and interpret Nuclear Medicine exams. _ Radioactive material should be used in designated areas. _ No eating/drinking in radioactive material areas. _ Lab coats, syringe shields and gloves must be utilized when handling radioactive material. _ Survey and wipe test areas for potential contamination. Restricted Area Action Levels: 1mR/hr & 1000dpm per 100cm2.
17 Guidelines for Security _ Isotopes are routinely delivered to the designated area during normal business hours. _ For off our delivery, the radioactive material transporter should check in with security and be escorted to the designated area for isotope delivery. _ Only authorized personnel are to enter Radioactive Material storage areas. Should staff need entry to these areas, the Nuclear Medicine supervisor or Radiation Safety Officer should be contacted.	18 General Environmental Services Guidelines _ Clean in authorized areas only _ Do not enter hot lab unless authorized to do so or under direct supervision _ Do not empty containers with radioactive label
19 Radiation Safety Officer _ Any institution that uses radiation for diagnostic and//or therapeutic purposes must name a Radiation Safety Officer (R.S.O.) _ This individual is responsible for the day to day safe use off radiation at the institution _ All unsafe conditions must be reported to the R.S.O.