How do radiographers protect themselves from radiation?
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Everyone knows that people who work around radiation need to use some kind of radiation protection. Radiation comes in several forms and affects the body differently. The three main principles of protection are shielding, distance and time of exposure. Show ShieldingRadiologists prepare a patient for an x-ray by laying a protective apron over them. The technologist then moves to an enclosure or exits the room. There are several other types of protection, all of which have the same basic principle in mind — they all use lead as a barrier between the technologist and the radiation. Lead works great because it absorbs the radiation. Its density stops the radiation, absorbs it and converts it to harmless heat. The heat is then dispersed from the lead lining and the radiation is dissolved in the process. Shielding itself can be worn as an apron, glasses or hung as drapes, which can be stationary or on a mobile cart. DistanceThe farther away a person is from the source of the radiation, the lesser the amount of radiation is absorbed. In most medical environments, the technician positions himself several feet away from the radiation source. Since high doses are not administered by medical equipment, simple distance, in conjunction with shielding, provides adequate protection for the radiologist. It also ensures that people moving around in other areas of the hospital are not affected. Time of ExposureAnyone who has had an x-ray knows that they do not take long; however, radiation does stay in the body. If an x-ray takes 2 seconds to process and the technician takes 30 x-rays a day, that is the equivalent of being exposed for an hour. The reason why this exposure factor is mitigated is because of shielding and distance. Radiation levels are low enough that a technologist could do his job for 20 years and possibly have no side effects, depending on other factors. According to the American Registry of Radiologic Technologists (ARRT) different organs have variable resistances to radiation. The term "effective dose" is the average dose the human body can absorb as a whole. There are several new radiation safety improvements under consideration, but the best safety is knowledge. According to Cath Lab Digest, the biggest issue with radiation safety is improper personnel training. They recommend that any and all employees who work around radiation equipment should look at taking a radiation safety course. A combination of proper radiation protection and safety procedures will protect both the employees and patients from harmful outcomes that may arise from radiation exposure. This section does not address the range of non-radiological safety and health hazards for workers in occupational settings with ionizing radiation hazards. For example, these non-radiological safety and health hazards may include electrical hazards from associated electrical equipment and extension cords, shift work and long work hours, worker ingress (entry) into and egress (exit) from shielded enclosures (e.g., at fixed industrial radiography facilities), and laser hazards if lasers are incorporated into radiation-emitting equipment (e.g., lasers are sometimes used to align an external beam with the target).
Radiation Protection Program Developing and implementing a radiation protection program is a best practice for protecting workers from ionizing radiation. A radiation protection program is usually managed by a qualified expert (e.g., health physicist), who is often called a radiation safety officer (RSO). Another best practice is designating a radiation safety committee, which includes the RSO, a management representative, and workers who work with radiation-producing equipment, radiation sources, or radioactive materials (or who are otherwise at risk of exposure on the job). A radiation protection program should include, at a minimum: Equipment Registration/Licensing Federal and state regulatory agencies require some types of radiation-producing equipment or radiation sources to be registered or licensed by manufacturers and/or users. Registration or licensing requirements apply to many specific radiation sources and occupational settings (e.g., , ). Equipment registration or licensing helps ensure that radiation sources emitting ionizing radiation do not pose radiation hazards for workers (and the public). Some radiation sources, such as most and some , must be registered with a state agency (e.g., , state health department) or local agency (e.g., health department) and different registration requirements may apply, depending on the agency. Registrants may be required to perform equipment tests or allow state or local inspectors to perform equipment tests. In some states, equipment registration requirements may include regular inspections, , or signage.
(U.S. Nuclear Regulatory Commission) regulations for radiation protection programs (10 CFR 20.1101) or for such programs apply to some specific radiation sources and . OSHA's Ionizing Radiation standards apply where they are not pre-empted, and, in those cases, require certain elements of a radiation protection program. ALARAA key concept underlying radiation protection programs is keeping each worker's occupational radiation dose As Low As Reasonably Achievable (ALARA). An ALARA program usually involves maintaining radiation doses to workers as far below the federal and state regulatory occupational dose limits as is reasonably achievable taking into consideration the state of technology, economics, and social factors. ALARA in the workplace minimizes radiation doses and releases of radioactive materials using all reasonable methods available. ALARA procedures are typically developed for working with specific radiation sources, for example, diagnostic (e.g., medical X-rays), in medicine, or . Time, Distance, and Shielding When it comes to ionizing radiation, remember time, distance, and shielding:
Time, Distance, and Shielding for Radiation Protection Source: NRC  Engineering Controls Employers should use engineering controls to maintain occupational radiation doses (and doses to the public) is applied after determining that radiation dose will not exceed applicable regulatory dose limits. To the greatest extent possible, should not be used as substitutes for engineering controls. Engineering controls, in some cases, may be incorporated into facility design. Some examples of engineering controls are discussed below, including and . In addition, radioactive material containment is sometimes incorporated into shielding, such as in gamma cameras used for nuclear medicine or industrial radiography devices containing a radioactive source. Shielding The need for shielding depends on the type and activity of the radiation source. Uses in adjacent areas, including the areas above and below the room or facility, should also be considered. For shielding of rooms containing medical or rooms with other medical X-ray imaging devices, the National Council on Radiation Protection and Measurements (NCRP) recommends that the shielding design goal be 500 mrad (5 mGy) in a year to any person in controlled (restricted) areas. For uncontrolled (unrestricted) areas, NCRP recommends that the shielding design goal be a maximum of 100 mrad (1 mGy) to any person in a year (~0.02 mGy per week). Shielding design requires a qualified expert (e.g., health physicist). Before using any new or remodeled rooms or facilities or any new or relocated , a qualified expert should conduct an and evaluate shielding to verify radiation protection behind shielding materials. Before performing any room modifications or if any changes occur to a facility that may change radiation exposure levels (e.g., new equipment, increased workload, altered use of adjacent spaces), a qualified expert should review the shielding design. In general, the floors, walls, ceilings, and doors should be built with materials that provide shielding for the desired radiation protection. Lead shielding may be installed, if appropriate, including leaded glass, sheet lead (e.g., built into walls), pre-fabricated lead-lined drywall or lead-lined plywood, pre-fabricated lead-lined doors and door frames, lead plates, and lead bricks. Sometimes it may be sufficient to construct a wall of a suitable thickness of normal building materials (e.g., dense concrete). The shielding design may include a control booth or load/lead-equivalent drapes provided for protection of workers operating equipment or devices that emit ionizing radiation. More information on shielding criteria is provided in the following NCRP reports:
Portable or temporary shielding materials (e.g., thick steel, lead, or high-density concrete blocks) can sometimes be fabricated in the area of the inspection when conducting portable (e.g., using industrial radiography cameras to inspect pipe welding or concrete slabs). Where such portable or temporary shielding is not practical or adequate to protect workers (and the public), employers should ensure that operating procedures maximize distance from the portable industrial radiography equipment while it is operating. When working with high-energy beta particles, avoid shielding with high atomic number (Z>13) materials as this can result in production of X-rays (Bremsstrahlung radiation), which are more penetrating than the original beta radiation. Beta particles should be shielded using an appropriate thickness of low atomic number (Z<14) materials such as aluminum or plastics (e.g., Plexiglas®). Interlock Systems A radiation safety interlock system is a device that automatically shuts off or reduces the radiation emission rate from radiation-producing equipment (gamma or or ). The purpose of a radiation safety interlock system is to prevent worker exposure and injury from high radiation levels. Typically, interlock systems are required by state or federal (e.g., , (U.S. Food and Drug Administration)) regulations for . In most applications, interlock systems to stop X-ray or particle beam production can be activated by the opening of a worker access point (e.g., door) into a controlled (restricted) area. Interlock safety systems may also include door pressure sensors or motion detectors. For applications involving high-energy radiation sources, a system with interlock keys can control access or prevent entry into a radiation treatment room or during accelerator operations. Because removal of interlock keys will stop X-ray or particle beam production, such interlock systems rely on constant monitoring of all interlock keys and appropriate worker training for controlled access to high radiation areas. In addition to worker safety, patient safety is a concern for interlock systems for medical X-ray equipment or accelerators. NCRP recommends that interlock systems that stop X-ray or particle beam production should not be placed on doors to any diagnostic or interventional X-ray room to prevent inadvertent patient injury or the need to repeat exposures to patients.1 As an alternative, appropriate access control measures could be implemented at such facilities for both worker and patient radiation safety. When used, interlock systems should be inspected regularly by a qualified expert. Administrative Controls Administrative controls generally supplement engineering controls. Examples of administrative controls include signage, warning systems, and written operating procedures to prevent, reduce, or eliminate radiation exposure. Operating procedures typically include both normal operating procedures and emergency procedures (i.e., those for spills, leaks, and emergency evacuation). OSHA's Ionizing Radiation standards specify certain types of administrative controls in worksites where they apply. The bullets below provide more details about specific posting provisions for rooms in workplaces covered by the Ionizing Radiation standard for general industry (29 CFR 1910.1096)—including on vessels and on shore in shipyard employment, marine terminals, and longshoring. Employers may also be required to comply with provisions of other OSHA standards, including the Ionizing Radiation standards for construction (29 CFR 1926.53), which incorporates by reference the same types of controls described in the general industry standard, and shipyard employment (29 CFR 1915.57), which applies the NRC's Standards for Protection Against Radiation (10 CFR part 20) to activities involving the use of and exposure to sources of ionizing radiation on conventionally and nuclear-powered vessels.
Warning Systems Warning systems can be integrated into the design of radiation-producing equipment or devices and can also be used with radioactive materials. Such warning systems will set off an audible (easy to hear) alarm (e.g., to warn workers that a radiation hazard exists) or a visible (lighted) warning signal whenever ionizing radiation is being emitted. As an example, industrial radiography equipment located in a fixed facility or room (e.g., industrial radiography room for conducting materials testing for quality control at a manufacturing facility) may include visible warning signals with colored or flashing lights or audible alarms with a distinct sound, which are located inside and outside the shielded enclosure for conducting industrial radiography. In this example, the visible alarm would activate when the radiation source is exposed or when or are generated during industrial radiography operations. The audible alarm would sound if the door is opened to the shielded enclosure for the industrial radiography equipment. Other facilities, such as gamma irradiation facilities, also use warning systems. Warning systems should be checked regularly for proper function. Radiation Exposure versus Contamination For more information about radiation exposure and how it differs from contamination, see the Background page for: A worker can be exposed to radiation and receive a without being contaminated with radioactive materials. Warning systems should be checked regularly for proper function. Personal Protective Equipment Personal Protective Equipment (PPE) is used to prevent workers from becoming contaminated with radioactive material. It can be used to prevent skin contamination with particulate radiation (alpha and beta particles) and prevent inhalation of radioactive materials. PPE will not protect workers from direct, external radiation exposure (e.g., standing in an X-ray field), unless the PPE contains shielding material. For example, a leaded apron will reduce X-ray doses to covered areas. Consult a qualified expert (e.g., a health physicist) when choosing PPE and developing a PPE policy for a workplace. Consistent with the hierarchy of controls, PPE should only be used when appropriate engineering controls or administrative controls are infeasible. Alpha Radiation have very low penetrating power, travel only a few centimeters in air, and will not penetrate the dead outer layer of skin. Shielding is generally not required for alpha particles because to alpha particles delivers no radiation dose. Where particulates contaminated with alpha particles are present, engineering controls (e.g. glove boxes) or respiratory protection may be required to prevent an and dose. More information about is provided below. When working with liquid sources that contain alpha particles, additional PPE, such as gloves, a lab coat, and safety glasses, may be required to prevent contamination or contact with the eyes. Beta Radiation High-energy can travel several meters in air and can penetrate several millimeters into the skin. For high-energy beta particles, first select adequate with an appropriate thickness of low atomic number (Z<14) materials, such as specialized plastics (e.g., Plexiglas®) or aluminum. Using safety goggles as PPE can help protect workers' eyes against beta particles as well as provide splash protection for the eyes (preventing potential ). Gloves and a lab coat may be used to prevent skin contamination. X-ray and Gamma Radiation and can travel kilometers in air and can penetrate deep into the human body or pass through it entirely. Proper shielding should be in place to prevent or reduce radiation dose rates. Some PPE for worker protection from gamma and X-rays incorporates lead or other dense, high atomic number (high Z) materials. As described under the section, it is also important to consider the inverse square law for gamma and X-rays when choosing appropriate PPE. Examples of commonly used PPE for radiation protection from X-rays and gamma rays include:
Respirators Although respirators are typically the last choice for controlling internal exposure to airborne radionuclides, reducing internal radiation dose, employers should ensure that workers use properly selected respirators and wear those respirators when required. Respirators should only be used by workers qualified to wear them. See 29 CFR 1910.134 for requirements for using respiratory protection. Radiation Measurement and Sampling OSHA's Ionizing Radiation standards often require employers to monitor radiation exposure, including by measuring radiation levels in the work environment and tracking the radiation doses that workers receive. Several types of area monitoring, personal dosimetry, and sample analysis equipment and techniques may be involved in effective radiation measurement efforts. This section discusses Survey Instruments Radiation survey instruments can be used to evaluate exposure rates, dose rates, and the quantities (activity) of radioactive materials and contamination. The survey instrument must be appropriate for the type and energy of the radiation being measured. A qualified expert should provide oversight for selecting appropriate area survey instruments, using survey instruments properly when conducting area surveys or monitoring, interpreting survey results, and ensuring accurate calibration and maintenance. Under OSHA's Ionizing Radiation standards, employer responsibilities typically include surveying radiation hazards to comply with the standard (, 29 CFR 1926.53). This is true for most operations in general industry, construction, shipyards, marine terminals, and longshoring.
Handheld Survey MetersHandheld survey meters are the most widely used and recognizable instruments for measuring ionizing radiation. These meters are typically used to measure radiation exposure rate, dose rate, or evaluate levels of radiological contamination. These types of instruments include ionization detectors, Geiger-Muller (GM) detectors, proportional detectors, or scintillation detectors. Each type of instrument has unique characteristics, and a radiation professional should be consulted to select a handheld survey instrument best suited to the application.Radioisotope Identification DevicesRadioisotope Identification Devices (RIID) are hand held radiation instruments designed to identify the radioactive isotopes in a radiation source. A RIID is often a small handheld device designed to be easy to operate. These instruments use a scintillation detector in order to evaluate gamma energies emitted by a radioactive source and comparing the measured gamma spectrum to libraries of characteristic gamma spectra.Personal Radiation DetectorsPersonal Radiation Detectors (PRD) are small electronic devices designed to alert the wearer to the presence of radiation. These devices are often used to monitor for illicit radioactive materials. A type of PRD, a Spectroscopic Personal Radiation Detectors (SPRD), can also measure the gamma spectrum of the radiation source, which can be used to identify the radioisotopes present. Dosimetry OSHA’s Ionizing Radiation standard requires employers to conduct dose monitoring when a worker who enters a restricted area receives or is likely to receive a dose in any calendar quarter in excess of 25% of the applicable occupational limit (or 5% for workers under age 18) and for each worker who enters a high radiation area ( and , 29 CFR 1926.53). See the Standards page for information about OSHA’s Ionizing Radiation Standard. An employer’s radiation protection program may require more stringent for workers who enter restricted or high radiation areas, or use equipment or conduct job tasks that produce high levels of radiation (e.g., fluoroscopically-guided , other , , ). Dosimeters Radiation dosimeters are devise used to measure the amount of external radiation dose received by an individual. Dosimeters are typically assigned to an individual to record only their radiation dose. Badge type dosimeters include thermoluminescent dosimeters (TLD), optically stimulated luminescent dosimeters (OSL), and film badges. These types of dosimeters are typically worn for a specified period, most commonly monthly or quarterly, and are then sent to a commercial laboratory for processing. Electronic person dosimeters (EPD) can also be used to monitor an individual’s radiation dose. These devices can provide a continuous readout of the wearer’s radiation dose, dose rate, and can be set to alarm at user defined dose thresholds and dose rates. Pocket ion chambers (PIC) can also be used to provide a real time measurement of the wearer’s cumulative radiation dose. A PIC can be read by the wearer by looking through an eyepiece at the end of the device and viewing the deflection of the quartz fiber inside. Use of these devices is now very limited having largely been replaced with the use of EPDs. Radiological Sampling and Analysis Sampling and analytical methods and equipment allow radiation safety professionals to identify areas with radioactivity, including where radioactive materials have contaminated environmental surfaces and other objects as well as environments that have radioactive materials in the air. Radiation safety professionals also use such methods and equipment to quantify how much radiation is present in order to determine how best to protect workers. This section discusses several sampling methods. Contamination Sampling Radiological contamination sampling is used to evaluate the presence of unwanted radioactive materials, also known as contamination, deposited in an uncontrolled manner on or in objects and on surfaces. Radiological contamination is often referred to as fixed or removable. Fixed contamination is radioactive materials that are not easily removed from the object or surface. Removable contamination is radioactive material that is easily removed from the object or surface. Adding the amount of fixed and removable contamination provides the amount of total contamination. The amount of total contamination can be measured using survey instrument equipped with an appropriate detector, such as a GM detector or a scintillation detector. Removable contamination is measured by wiping a known surface area, often 100 cm2, then measuring the amount of radioactive material on the wipe sampler using an appropriate instrument such as scaler / counter equipped with a proportional or scintillation detector. The Department of Energy provides guidance for surface contamination values in 10 CFR 835 Appendix D. Contamination sampling, analysis, and interpretation of results should be conducted under the direction of a radiation safety professional. Air SamplingRadiological air sampling is used to determine the amount of radioactive materials suspended in the air. This sampling is often conducted to evaluate the need for engineering, administrative, or respiratory protection by comparing results to appropriate airborne exposure limits. Air sampling and analysis should always be conducted under the direction of a radiation safety professional.Personal and Area SamplingPersonal and area air sampling are conducted by using a pump to pull a known volume of air through sampling collection media, such as a filter cassette. Personal air sampling collects air from the breathing zone of a worker, while an area sample collects general room air. Once sampling is completed the sample media is evaluated using appropriate detection equipment for the radionuclides being evaluated. Some types of analysis equipment are scaler/counters, proportional counters, scintillation counters, liquid scintillation counters, gamma spectroscopy, and alpha spectroscopy. Continuous Air MonitorsContinuous air monitors (CAM) can be used to evaluate the presence of airborne radioactive material. These devices can be used to alert personnel to an increased level of radioactive material in the air that may require some action, such as evacuation. These devices use a pump to draw air through a particulate filter or gas chamber that is continuously monitored with a radiation detector. These devices can often be set to trigger an alarm at a user specified level of measured airborne radioactivity.Radon MonitoringMeasurements of the concentration of radon in air can be conducted using several different methods. Diffusive samplers can be deployed for several days to months to measure the average airborne radon concentration over the sampling period. Commercially available radon test kits are an example of a diffusive type sampler. OSHA Method ID-208 is a diffusing sampling method that describes the use of a short-term (2-7 day) electret-passive environmental radon monitor (E-PERM). Direct reading portable airborne radiation monitors can be used to provide a nearly instantaneous measurement of airborne radon concentration. These monitors typically draw air into the instrument and rely on devices such as a scintillation detector or a pulsed ion chamber to measure alpha particles emitted by the radon gas or radon decay products. Most of these devices are capable of performing sequential short-term measurements (minutes) and logging the data over a relatively long period (weeks). These instruments allow radiation professionals to determine how radon levels vary within a space and vary over time. Sample Analysis Equipment Radioactive samples can be evaluated using a variety of equipment types depending on the type of sample (e.g. air, water, soil, surface wipe) and the types of radiations emitted by the sample. The following are examples of some of the types of equipment used to evaluate radioactive samples. Scaler / CountersThese devices are often portable and are used to measure the amount of alpha or beta radiations on a radiological sample. A sample, such as an air sample or surface wipe, is placed near the internal radiation detector and the radiations are counted for a user specified time. The device registers the total number of radiations counted over the measurement time. Scaler / counters are sometimes equipped with scintillation detectors, G-M detectors, proportional detectors, or passivated implanted planar silicon (PIPS) detectors.Liquid Scintillation CountersA liquid scintillation counter is piece of equipment that is not portable and is usually used in a laboratory. This instrument can be used for all types of radiations, but it is most often used for measuring beta particles. In liquid scintillation counting, the sample is place in a transparent glass vialed that is then filled with a scintillation fluid. Radiations from the sample that interact within the fluid cause the fluid to emit photons of light. The intensity of the light is proportional to the energy of the radiation. This allows for the determination of what the radioactive material is (radioisotope identification) and how much radioactive material is present (radioactivity).Gamma SpectroscopyGamma spectroscopy is a method used to identify the radioisotopes present in a radiological sample and quantify the amount of radioactivity in that sample. While these devices can be handheld like the RIID, the most sensitive and accurate instruments are not portable and are used in the laboratory. Common detectors used for gamma spectroscopy are semiconductor-based detectors such as germanium, cadmium telluride, and cadmium zinc telluride detectors, and scintillation detectors such as sodium iodide (NAI) detectors.Alpha SpectroscopyAlpha spectroscopy is a method used to identify and quantify alpha emitting radioisotopes. Radioactive samples are chemically digested and the solution is placed onto a thin metal disk. The amount of radioactivity on the disk is measured using a radiation detector, most often a PIPS detector. These instruments are not portable and are typically only used in a laboratory. Whole Body Counting A whole body counter is a detector, or series of detectors, used to measure the amount of radioactivity in the human body. These instruments rely on the measurement of gamma and x-rays emitted from the radioactive material deposited in the body. Gamma spectroscopy systems are usually used in whole body counting systems. Counting is often used in occupational settings to conduct measurements of radiological workers at the beginning of employment, periodically during employment, after known or suspected intakes, and at the termination of employment in order to determine occupational radiation doses. Bioassay Sampling Bioassay sampling is sometime used in occupational settings to determine the uptake of radioactive material for radiological workers. Samples are typically collect at the beginning of employment, periodically during employment, after known or suspected intakes, and at the termination of employment in order to determine occupational radiation doses. Bioassay samples most commonly include urine, feces, and blood. Worker Training One of the most important functions of a radiation protection program is training radiation workers on safe work practices. Employers should provide workers with information and training to ensure that those who are potentially exposed to ionizing radiation hazards understand how to safely use all radiation-producing equipment or radiation sources in the workplace. Providing workers with information and training is closely tied to awareness of regulations because federal and state regulations often include performance and safety standards for specific radiation-producing equipment or radiation sources. Employers should ensure that workers understand mandatory performance and safety standards that help protect workers from exposure to ionizing radiation. Some state agencies may regulate the operation of electronically-produced radiation equipment through recommendations and requirements for personnel qualifications (e.g., licensing or certification), quality assurance and quality control programs, and facility accreditation. Those mandatory personnel qualifications are another important part of protecting workers from exposure to ionizing radiation. For more information, read the American National Standards Institute (ANSI)/Health Physics Society (HPS) N13.36, Ionizing Radiation Safety Training for Workers. Hazard-Specific Control Resources In addition to the general methods of control described above, there are several resources included on the Additional Resources page that provide information on controlling specific radiation hazards, including medical sources (i.e., diagnostic X-rays and fluoroscopically-guided interventional procedures), dental and veterinary X-rays, particle accelerators, industrial radiography, security screening, and radon. 1 U.S. Environmental Protection Agency (EPA). (2014). Publication No. EPA-402-R-10003, Federal Guidance Report #14, Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures. Washington, DC: EPA; National Council on Radiation Protection and Measurements (NCRP). (2004). Report No. 147: Structural shielding design for medical x-ray imaging facilities. Bethesda, MD: NCRP. Are radiographers exposed to radiation?Although a radiographer wears an apron, radiation exposure of his/her head, eyes, face, neck, hands, feet for one year could exceed 10 mSv according to his/her position and the number of procedures.
How can a radiographer minimize radiation exposure?Digital X-ray detectors, special X-ray beam filters, and other new technologies reduce radiation doses in radiography, mammography, and fluoroscopy.
How can you protect yourself from radiation exposure?Staying inside will reduce your exposure to radiation.. Close and lock windows and doors.. Take a shower or wipe exposed parts of your body with a damp cloth.. Drink bottled water and eat food in sealed containers.. What are the three principal methods used to protect radiographers from unnecessary radiation exposure?To do this, you can use three basic protective measures in radiation safety: time, distance, and shielding.
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