Radiation Basics. Rad Training for Clinical Laboratories. Key Points. What are 3 types of Ionizing particles/waves we are concerned with???

Transcription

1 1 Rad Training for Clinical Laboratories Jesse Fillmore Minnesota Department of Health PHLD, nvironmental Health RSO/RP Coordinator May 23, 2011 Key Points Radiation protection Laboratory Safety Purpose and operation of Rad equipment 2 After this training you should be able to: Define what radiation is Know the three types of radiation we are concerned with Think critically and safely in regards to radiation protection What are 3 types of Ionizing particles/waves we are concerned with??? Alpha Beta Gamma Know how to detect radiation and understand how your monitor(s) work Give examples of radiation health effects 3 4 Radiation Basics Radiation: Any process in which energy emitted by one body travels to be absorbed by another body. 5 6

2 7 Ionizing (Alpha, Beta, Gamma) Non-Ionizing Radiowaves Microwaves Visible Light 8 Protons Neutrons lectrons An atom with too many or too few neutrons contains excess energy and is not stable. Unstable atoms give off excess energy (radiation). Unstable atoms are radioactive Ionization: Converting an atom into an ion by removing charged particles. Main types of ionizing radiation: Alpha Particles Beta Particles Gamma and X-Rays (photons) Neutrons 11 12

3 13 Alpha Beta 14 Gamma Gamma 15 5/17/ Gamma Fission 5/17/

4 meters tall 65 mm (avg) 20 Change in magnitude of 1 9!! 381 meters tall 5.5 mm 5 um 21 5 um 22 Activity Detecting and Measuring radiation Curie: approximate activity of 1 g of Ra-226 isotope 1 Curie = 3.7 x disintergrations per second (dps) 1 Becquerel = 1 dps Becquerel= 1 pci 23 24

5 25 Fractions and Multiples Milli (m) = is 1/1000 of original amount (-3) Micro ( ) = 1/100,000 of original amount (-6) Pico (p)= is 1/1,000,000,000,000 of original amount. (-12) International Unit = Sievert (Sv) 1 Sv = 1,000 msv = 1,000,000 usv US Unit = Roentgen equivalent in man (rem) 1 rem = 10 msv 100 rem = 1 Sv Typical chest x-ray = 10 mrem (0.1 msv) Cross-country flight = 3 mrem (0.03 msv) 26 xposure and Dose Roentgen (R) the nergy of radiation; C/Kg at STP RAD radiation energy absorbed by any material; equal to 1 cgy; dose causing 0.01 J to be absorbed in 1 Kg of matter 70 mrm 300 mrm RM the biological dose equivalent; = 1 csv; D(ose) * W T * W R 1 R 1 RAD 1 RM (1 cgy) (1 csv) 27 HUMAN-MAD Naturally Occurring 28 Human Made Sources MAN-MAD S mrem/year Smoking (Tobacco Products) 1300 Medical X-rays 40 Medical Diagnosis and Therapy 14 Building Materials

6 31 Radiation Health ffects Acute xposure - Large exposure to radiation in a short period of time. Chronic xposure - Small exposure to radiation over a long period of time. 32 RADIOLOGICAL CONTAMINATION CONTAMINATION GOOD NOT SO GOOD RADIOLOGICAL CONTAMINATION IS RADIOACTIV MATRIAL PRSNT IN AN UNDSIRABL LOCATION RADIOACTIV LIQUID xposure limits General public 1 msv/yr What are the four pathways for internal contamination? Inhalation Ingestion Radiation Workers 50 msv/yr Radiation Workers in Japan after increased dose limit 250 msv/yr Absorption Puncture or Injection 35 36

7 37 < 20,000 MRM NO DTCTABL FFCTS 50,000 MRM DTCTABL BLOOD CHANGS 100,000 MRM ONST OF SICKNSS 600,000 MRM FATAL WITH NO MDICAL ATTNTION Cell Death Cell Repair Incomplete Repair 38 xposure Rate Instruments Inovision 451P Detector is inside plastic housing Detects gamma and x-rays Measures true exposure rate (mr/hr) 39 xposure Instruments Ludlum Model 3 with 44-9 pancake probe. Hold probe within 1 of surface being monitored Frisking rate: 2 to 3 inches per second Use speaker to locate contamination. 40 One Difference between CPM and Dose Difference between CPM and Dose 0.1 MeV 2.0 MeV 0.1 MeV 2.0 MeV 2000 photons/cm^2 100 photons/cm^ photons/cm^2 100 photons/cm^2 Calculated dose of about 200C/unit time Calculated dose of about 200C/unit time *C cpm 100*C cpm 20 x s higher cpm for this source! 42

8 43 Direct Reading Dosimeter (DRD) lectronic DRD - Ludlum Model xposure continues until contamination is removed Contamination can spread to other people and objects Contamination can enter the body through ingestion, inhalation, skin absorption, or open wound absorption 45 Contamination Monitoring Instruments Ludlum Model 3 with 44-9 pancake probe. Hold probe within 1 of surface being monitored Frisking rate: 2 to 3 inches per second Use speaker to locate contamination. 46 Contamination Control CONTAMINATION CONTROL SURVYS BOUNDARIS PROTCTIV CLOTHING RMOVAL & SGRGATION COVRINGS 47 48

9 49 A.L.A.R.A. TIM vs. XPOSUR As Low As Reasonably Achievable 100 mr/hr 1 FOOT Medical Safety comes first! S T A Y T I M 1 HOUR 2 HOURS 4 HOURS 8 HOURS 100 mr 200 mr 400 mr 800 mr X P O S U R 50 4 mr 5 FT D 25 mr I S T 100 mr A 2 FT X P O S U R N C 1 FOOT 51 S H I L D I N G XP O S U R 52 Limit Ingestion Practice proper lab safety Limit xposure; use ALARA Techniques Control Contamination Know where to find information Make sure your instruments are working properly Pressing medical concerns are addressed BFOR radiological concerns 53 54

10 Radiation Monitoring Radiation Monitoring RadNet (PA) Primary environmental monitoring >100 sites within U.S. Air, precipitation, ground water, milk 35+ years Nuclear fallout from weapons tests Radiologic emergencies (Chernobyl) Radiation Monitoring Radiation Monitoring MDH nvironmental Monitoring Additional sampling around power plants Detection of accidental release Water, plants, milk, air, soil FDA Food Monitoring Special order after Japan incident Screening of imported foods Same foods tested in Japan Tested at FDA labs in Winchester, MA FRN labs as surge capacity Radiation Monitoring Clinical Monitoring Post-exposure following radiologic incident (LRN-R) All testing at CDC (radiobioassay) Protocol similar to chemical incident Only collect urine (25 ml) health.state.mn.us/hazmat May Not Need to Take Blood

11 Resources Nuclear Regulatory Commission International Atomic nergy Agency MDH Lab mergency Preparedness MDH Radiation Control: MN Homeland Security mergency Management: nvironmental Health, Rad Control tion/monitor/index.html Resources Jesse Fillmore Radiation Safety Officer & Radiation mergency Preparedness Coordinator Minnesota Department of Health Public Health Laboratory Division