Presentation on theme: "RADIATION SAFETY RETRAINING LANGONE MEDICAL CENTER LANGONE MEDICAL CENTER Department of Radiation Safety 550 1 st Ave MSB G58 1-212-263-6888."— Presentation transcript:
RADIATION SAFETY RETRAINING LANGONE MEDICAL CENTER LANGONE MEDICAL CENTER Department of Radiation Safety st Ave MSB G
From The Beginning November 8, William Conrad Roentgen discovered the X-ray. February Henri Becquerel discovered radioactivity. January The first radiation burns from X-rays were reported. Becquerel and Pierre Curie both suffered burns from carrying vials of radium in their vest pockets. The Hazards Associated With Ionizing Radiation were Recognized
Standards Organizations were Established to Research and Advise on the Effects of Ionizing Radiation 1925: The First International Congress on Radiology meets in London. 1928: The Second International Congress on Radiology meets. 1929: The Advisory Committee on X-ray and Radium Protection is founded (Later becomes the National Council on Radiation Protection and Measurement (NCRP) 1950: The International Congress on Radiology changes its name to the International Commission on Radiological Protection (ICRP)
The Legislation Set Up Regulatory Agencies The Atomic Energy Act of 1946 and the1954 amendments to the Act established the Atomic Energy Commission to regulate source, special nuclear, and by-product material. 1959: The Federal Radiation Council is organized to control non- AEC materials. 1970: The EPA is established and the FRC becomes part of EPA. 1974: AEC is replaced by the DOE and NRC. UNK: DOT begins regulating the transport of radioactive materials. UNK: FDA regulates the performance of x-ray systems. UNK: OSHA regulates occupational exposures at non-NRC licensed facilities
New York is an Agreement State When the regulatory process for radioactive materials was first established by Congress many years ago, the regulation of most radioactive materials was turned over to the federal government. However, Congress established a process by which a state could apply to the Nuclear Regulatory Commission and take over the regulation of radioactive materials under certain conditions. When a state reaches such an agreement with the NRC, the state is called an Agreement State. The States regulations must be at least as conservative as the NRC, though they are permitted to be even more conservative. The NRC periodically reviews Agreement State programs and may rescind Agreement State status if a state does not perform satisfactorily.
Statutory Authority New York City The Federal Atomic Energy Act of 1954 authorizes “Agreement States” to regulate byproduct material, source material and special nuclear material in quantities not sufficient to form a critical mass. The New York State Sanitary Code delegates radiation licensure regulation to those localities that have a population of more than 2,000,000, New York State is an “Agreement State” within the meaning of the Act, and the New York City Department of Health and Mental Hygiene is a component of and a party to the relevant Agreement. The New York City Charter and applicable state and federal law grants the New York City Department of Health and Mental Hygiene jurisdiction to regulate matters affecting health in New York City specifically to regulate all aspects of ionizing radiation within the 5 boroughs of New York City.
The Radiation Safety Program Licensed by the Nuclear Regulatory Commission, New York State Department of Health or the New York City Department of Health & Mental Hygiene, The Radiation Safety Committee Oversees the radiation safety program Authorizes the use of radioactive materials Reviews incidents involving radioactive materials Sets policies for the use of sources of radiation The Radiation Safety Officer and Staff Advise on Radiation Protection Ensure Regulatory Compliance Provide Training Personal monitoring Incident, spill and contamination management Radioactive waste management
The Permit Holder Permit holders are faculty members or senior staff members who have been approved by the Radiation Safety Committee to use radioactive materials under specific conditions. Permit holders are responsible for: The health and safety of anyone using or affected by the use of radioactive materials under their permit Personally attending initial and annual refresher training Ensuring their employees, staff and visitors receive appropriate training Ensuring that their employees, staff and visitors comply with relevant regulations, policies and procedures Violation of NYUMC Radiation Safety Rules may result in suspension of radioisotope use privileges.
The Radiation Worker’s Responsibilities : Attend an initial radiation safety training class and an annual refresher training Be familiar with the isotopes in use; know their radiological, physical and chemical properties, methods of detection, types of hazards and specific precautions and handling requirements for each Be familiar with all the relevant procedures of the radiation safety program Know how to properly use the appropriate survey meter Wear appropriate radiation monitoring badges and exchange them promptly each quarter Maintain appropriate inventory, disposal and survey records Secure RAM by making sure they are locked away when not under immediate supervision in the laboratory Inform coworkers and visitors about the presence of RAM and of any precautions they should take Know how to handle spills and personal contamination and who to call for incidents involving sources of radiation
What is Radiation Radiation is energy given off by matter in the form of rays or high- speed particles. All matter is composed of atoms. Atoms are made up of various parts; the nucleus contains minute particles called protons and neutrons, and the atom's outer shell contains other particles called electrons. The nucleus carries a positive electrical charge, while the electrons carry a negative electrical charge. These forces within the atom work toward a strong, stable balance by getting rid of excess atomic energy (radioactivity).atomsnucleus protonsneutronselectronsradioactivity In that process, unstable nuclei may emit a quantity of energy, and this spontaneous emission is what we call radiation.
What is Ionizing Radiation Ionizing Radiation is radiation that has enough energy to break molecular bonds or remove electrons from atoms or molecules when it passes through or collides with some material. This electron displacement creates two electrically charged particles (ions), which may cause changes in living cells. Forms of Ionizing Radiation include : Gamma rays, X rays, Alpha particles, Beta particles and Neutrons.
Radioactive Half-Life (Decay) Radioactive Half-Life (Decay) Radioactive Decay is the process by which radioisotopes lose their radioactivity over time. This process is measured in Half-lives. Half-life (T½) is the time required for one half the radioactive atoms present to decay. Each radioisotope has a unique half life ranging from a fraction of a second to millions of years. Half-life (T½)
Forms of Ionizing Radiation Alpha Particles consist of heavy, positively charged particles emitted by atoms of heavy elements such as naturally occurring uranium and radium and some human-made sources. Alpha particles are completely absorbed by the outer dead layer of skin and are therefore not a hazard outside the body. If alpha particles are taken into the body by inhalation or with food or water, they can directly expose internal tissues. Example: Polonium 210 (Po-210), Americium 241 (Am-241), Plutonium 235 (Pu-235)
Forms of Ionizing Radiation Beta Particles (positively or negatively charged electrons) are emitted from the nucleus during decay. Beta particles are more penetrating than alpha particles and can sometimes penetrate the skin, but like alpha particles, they are generally more hazardous when inhaled or ingested. Beta particles may be stopped by plastic (Lucite) or wood. Examples: Tritium (H3), Phosphorous 32 (P32), Sulfur 35 (S35), Carbon 14( (C14)
Forms of Ionizing Radiation Gamma are forms of electromagnetic radiations or photons. They have both electric and magnetic properties. Gamma rays come from the nucleus when materials decay. Gamma rays can travel great distances and penetrate the body. Examples: Iodine 125 (I-125), Iodine 131 (I-131), Chromium 51 (Cr-51), Cesium 137 (Cs-137) X-rays are a kind of electromagnetic radiation generated when a strong electron beam bombards metal inside a glass tube. Neutrons are heavy, uncharged particles that cause the atoms that they strike to become ionized.
Measuring Ionizing Radiation Ionizing Radiation is measured in terms of: The strength or radioactivity of the source The energy of the radiation The level of radiation in the environment, and The radiation dose or amount of radiation energy absorbed by the human body For determining occupational exposures, the radiation dose is the most important measure. The risk of radiation-induced diseases depends on the total radiation dose that a person receives over time.
Units for Measuring Radioactivity The strength or radioactivity (activity ) is usually expressed as a rate of radiation emission from a source (not the energy of the emission). The units used are : The Becquerel – which is an extremely small amount of radioactivity. One becquerel (Bq) = 1 dps (disintegrations per second) 1 kBq=1000 Bq, 1 MBq=1000 kBq, 1 GBq= 1000 MBq The Curie – which is a large amount of radioactivity. One curie(Ci) = 3.7 x 1010 dps (disintegrations per second) One millicurie(mCi) = 3.7 x 107 dps = 1 x 10-3 Ci One microcurie (µCi) = 3.7 x 104 dps or dpm (1 x 10-6 Ci)
Measuring Radiation Exposure Radiation Energy: Ionizing radiation is measured in electronvolts (ev). Commonly used multiple units are keV=1000 eV and Mev = 1000 KeV Radiation Exposure: The Roentgen is the unit of radiation exposure in air and is expressed as the amount of ionization per unit mass of air. One Roentgen of gamma or x-ray exposure produces approximately 1 rad (0.01 gray) tissue dose. Radiation Dose: The amount of energy absorbed per unit weight of mass is called absorbed dose and is expressed in gray (Gy) or rad. 1 Gy = 100 rads
Radiation Dose Measurements Dose Equivalent: The measure of the biological effect of radiation requires a variable called the quality factor (QF). The quality factor takes into account the different degrees of biological damage produced by equal doses of different types of radiation. Effective Dose: The effective dose is the sum of weight equivalent doses in all the organs and tissues of the body Effective dose = sum of [organ doses x tissue weighing factor ] Tissue weighing factors represent relative sensitivity of organs for developing cancers.
Units of Radiation and Radiation Dose Quantity SI unit & Symbol Non-SI unit Conversion factor Radioactivity Becqueral, Bq Curie, Ci 1 Ci i= 3.7x10 10 Bq 1 Bq = 27 picocuries (pCi) Absorbed dose Gray, Gy rad 1 rad=0.01 Gy Dose (Equivalent dose) Sievert, Sv rem 1 rem – 0.01 Sv 1 rem = 10 mSv
ALARA –As Low As Reasonably Achievable Because some risk, however small, exists from any radiation dose, all doses should be kept ALARA ALARA includes reducing both internal and external dose Radiation exposure to the work force and public shall be controlled such that: – –Radiation doses are well below regulatory limits – –There is no radiation exposure without an overall benefit The ALARA concept is an integral part of all activities involving the use of sources of ionizing radiation ALARA is the responsibility of all employees
KEEPING RADIATION EXPOSURE ALARA Be familiar with the properties of the radioisotopes to be used Unfamiliar radioisotope procedures should be rehearsed before radioactive material is actually used Wear protective clothing Do not eat, drink, or apply make-up in the lab. For radioisotopes with significant radiation levels, use remote handling tools and shielding to limit direct handling of stock and sample vials. Survey frequently and extensively and clean up contamination in the work area promptly Change gloves and lab coats if they become contaminated Work in a hood when using volatile materials.
PERSONAL RADIATION MONITOR COMPLETE A FILM BADGE APPLICATION AND SCHEDULE RADIATION SAFETY TRAINING BEFORE YOU BEGIN USING RADIOACTIVE MATERIAL READ ATTACHED RSO POLICY INFORMATION MONITORS ARE ISSUED FOR A 1 or 3 MONTH PERIOD RETURN USED BADGE WHEN A NEW ONE IS RECEIVED NOTIFY RSO IF YOU DO NOT RECEIVE A NEW BADGE YOU WILL BE NOTIFIED IN WRITING IF YOUR MONITOR RECORDS A DOSE WHICH EXCEEDS 1/20 OF THE ANNUAL LIMIT YOU WILL RECEIVE AN INDIVIDUAL REPORT OF YOUR EXPOSURE AT THE END OF EACH YEAR AFTER ALL MONITORS HAVE BEEN RETURNED AND POCESSED
OCCUPATIONAL DOSE LIMITS FOR RADIATION WORKERS Dose 1 to Whole Body Dose to extremity Dose to skin or organ Dose to lens of eye Dose to fetus 2 5 rems(0.05 Sv)/year 50 rems(0.5 Sv)/year 15 rems(0.15 Sv)/year 0.5 rem(0.005Sv)/gestation 1.Effective dose equivalent, which is the sum of the doses from external radiation + any internally deposited radioactive materials. 1/10 the limits if under 18 2.This limit applies to the fetus of an employee who has formally notified the RSO that she is pregnant. Dose Limit For the Public: The total effective dose to the individual will not exceed 100 mrem/yr
WORKERS RIGHTS It is your right to be informed of the hazards of your work environment. You should receive a written annual exposure report. You may receive a verbal report upon request. You will receive written notification from the RSO: – –If your monitor is issued quarterly and it records a dose in excess of 1/20 the annual dose limit – –If your monitor is issued monthly and if records a dose in excess of 1/50 the annual dose limit; – –If unusual exposure patterns are observed. Your radiation exposure history will be transferred between places of employment, e.g. previous, future, multiple employers upon request. Pregnant radiation workers who declare their pregnancy to the RSO will receive a second badge worn at the abdomen, change monthly, used to estimate any fetal dose.
Internal Exposure Internal Exposure can occur when a radioisotope enters the body by inhalation, ingestion, absorption through skin, or through an open wound. If this happens, any kind of radiation can directly harm living cells. The damage the radiation produces depends on the following factors: – The amount of radioactive material deposited into the body – The type of radiation emitted – The physical characteristics of the element; – The half-life of the radioisotope (how fast it decays away) – The length of time in the body. Radioactive material inside human body will cause an internal dose. You can NEVER eat or drink in a posted radioactive material lab!
External Exposure External Exposure comes from a source outside the body, such as a medical x-ray. To do harm, the radiation must have enough energy to penetrate the body. If it does, three factors affect the radiation dose that the individual will receive: The amount of time the individual was exposed The distance from the source of radiation The amount of shielding between the individual and the source of radiation.
SHIELDING The following shielding guidelines can be used: Alpha particles (α) stopped by paper Beta particles (β) stopped by wood or Plastic (Plexiglass, Lucite) Gamma (γ) and X-rays (X) stopped by lead or concrete Neutrons (η) absorbed by hydrogen-rich materials (i.e. concrete) Placing material between the source of radiation and people working nearby is considered SHIELDING.
Post Appropriate Warning Signs On the door of laboratories where Radioactive materials are used or stored. On Refrigerators, freezers, fume hoods, work benches, sinks, storage and waste containers used for RAM work. On centrifuges and other equipment used for RAM work. When using small fabricated or shielded containers as interim waste containers at a work station make sure that radioactive warning labels are blatantly affixed to all visible sides. Notice to Employees and Emergency Procedures must be posted.
Be Aware of and Follow Emergency Procedures Theft or Loss of any ionizing radiation source: Notify the Radiation Safety Officer immediately Accidents involving radioactive dusts, mists, fumes, vapors or gases: Evacuate the room immediately, close the door, notify the RSO. Contamination of personnel by radioactive materials: Flush contaminated skin or eyes with water immediately Remove and confine contaminated clothing. Notify RSO for instructions. Obtain a survey meter, check for contamination, begin to decontaminate with soap and water, avoiding spread of contamination. Retain all materials used for decontamination. Report injuries following standard procedures.
Types of Contamination Removable Contamination Can be readily removed using proper decontamination procedures. Removable contamination in any amount may present both an external and internal hazard because it can be picked up on skin and possibly ingested. Fixed Contamination Cannot be readily decontaminated. Fixed contamination generally does not present a significant hazard unless the material comes loose or is present in such large amounts that is presents an external radiation hazard.
When to Survey At the end of an experimental procedure At the end of each day for multi-day procedures Frequently during the manipulation of millicurie (mCi) quantities of open sources During and following the opening of radioactive material packages Following withdrawals from stock vials containing more than 1 mCi Prior to exiting the laboratory (for personal surveys)
Meter Surveys - Every time RAM is Used using Geiger detectors or scintillation probes, can identify gross contamination (total contamination consisting of both fixed and removable contamination). Will detect only certain isotopes. Wipe Surveys – At least done monthly using "wipes" counted on a liquid scintillation counter or a gamma counter, can identify removable contamination only. Will detect most isotopes used in research. Wipe tests are the most versatile and most sensitive method of detecting low-level contamination in the laboratory. Meter Surveys - Every time RAM is Used using Geiger detectors or scintillation probes, can identify gross contamination (total contamination consisting of both fixed and removable contamination). Will detect only certain isotopes. Wipe Surveys – At least done monthly using "wipes" counted on a liquid scintillation counter or a gamma counter, can identify removable contamination only. Will detect most isotopes used in research. Wipe tests are the most versatile and most sensitive method of detecting low-level contamination in the laboratory. Types ofSurveys Types of Surveys
Performing a Meter Survey Using a survey meter Check battery condition – needle should go to BAT TEST line on meter Turn large switch to the lowest scale – turn on audio switch. Note meter “background” reading in a location away from radiation source. Check that meter responds to the radiation being measured Place probe (window face down) about ½ inch from surface being surveyed. Try not to let probe touch surfaces being checked. Survey work area by slowly moving probe over surfaces, listen to audible “clicks” from survey meter speaker.
How to Perform a Wipe Test Using a piece of filter paper (about 1" in diameter), Q-tip or other swab, wipe the area being surveyed. If the area is very large, subdivide it into smaller areas and use several wipes to better pinpoint the location of contamination, For some surfaces, including skin and clothing, the wipe media should be moistened with water or other appropriate solvent. Prepare the same for counting as suggested in the counter's operating manual. Analyze the wipe samples in a liquid scintillation counter for H-3 and other beta emitters and preferably in a gamma counter for Cr-51 and I-125. Sample activity (DPM) is determined by dividing the sample count by the counter's efficiency for the isotope in question. Record results in DPM not CPM.
Document Surveys Record survey results in a laboratory survey log: when amounts of radioactivity of 250 Ci or more have been handled, whenever contamination is discovered, regardless of the amount used, to show follow-up actions, whenever contamination has been cleaned up Each log entry should contain : Name of person performing the survey Date of survey Brief description of the area surveyed Survey meter results (in cpm), Wipe test results (in DPM) Instrument used including Meter identification (model, serial number) Follow-up action taken when contamination is found.
Be Familiar with Waste Procedures
Maintain Records of Radioactive Material Package Receipts and Isotope Usage Logs
Know Radiation Safety Office Policy Statements Model Rules for Safe Use of Radioactive Materials No Food Storage in Laboratories Purchases and Acquisitions Transfer and Transportation Maintain a Logbook Perform Wipe Checks Use of Non-Hazardous Liquid Scintillation Cocktails Do Not Generate Mixed Waste Test Your Radiation Safety Knowledge! Take the test Take the test