Background radiation is all around us, and always has been. That idea can be a frightening concept at face value, but the truth is background radiation is natural, normal, and expected.
Most natural background sources of radiation fall into one of three categories:
Cosmic Radiation
Think of this as steady waves of external radiation being sent from the sun and stars in space to Earth. This type of radiation occurs naturally and introduces extremely low levels of radiation to the average person. The amount (or dose) of cosmic radiation one receives can depend on weather and atmospheric conditions, the Earth’s magnetic field, and differences in elevation. For example, people who live at higher altitudes like Denver, Colorado are exposed to slightly more cosmic radiation than people who live in lower altitudes, such as New Orleans, Louisiana or Miami, Florida. Furthermore, the farther north or south one is from the equator results in a higher dose of cosmic radiation due to the way the Earth’s magnetic field deflects cosmic radiation toward the North and South poles.
Air travel can also expose individuals to low levels of cosmic radiation. The received dose is similarly dependent on altitude, latitude, and the duration of the flight. A coast-to-coast flight in the United States would expose an individual to approximately 3.5 mrem. For comparison, a typical medical procedure involving radiation, such as a chest X-ray, exposes an individual to 10 mrem, and the average American receives a total radiation dose of 540 mrem each year.
In general, a person’s average dose from cosmic radiation in the United States is small, making up only 6% of their total annual dose.
Terrestrial Radiation
Terrestrial radiation is the portion of natural background radiation that is emitted by naturally occurring radioactive materials on earth, and it is responsible for approximately 3% of the average person’s annual received dose. The physical earth, including soil and sedimentary and igneous rock, contains common elements like uranium, thorium, and radium. These naturally occurring radioactive materials, which have existed as part of the earth’s crust since the earth was formed, are released into the water, vegetation, and the atmosphere as they breakdown at different rates. People are largely exposed to the resulting emitted radiation through their skin.
Radon:
Perhaps the most significant form of terrestrial radiation is that which is inhaled. When the naturally occurring radioactive element uranium (found in the earth’s crust, underwater caves, and seawater) decays it can change into a scentless, invisible gas called radon. All the air we breathe contains trace amounts of radon, and it is responsible for the largest portion of background radiation dose that the average American receives in a year. Outdoors, this radioactive gas disperses rapidly and does not pose any health risk to human beings. A build-up of radon gas indoors, however, can potentially increase the risk of lung cancer over time, which is why it is important to test homes and workplaces for radon on a regular basis. Smoking, especially near or inside the home, can amplify the risk of cancer when coupled with radon exposure.
The average person can expect to receive 42% of their annual radiation dose from radon.
Internal Radiation
Background radiation can also be received through ingestion. Some common foods contain small amounts of radioactive elements that do not pose a radiation risk to the person ingesting them. The most common example is the banana. This delicious, nutritious fruit contains naturally high levels of potassium which helps muscles contract, keeps your heartbeat regular, and offsets the harmful effects of sodium on blood pressure. A tiny portion of potassium is also naturally radioactive. A single banana emits 0.01 mrem, which is received internally by the person eating it. According to the EPA, a person would have to eat 100 bananas to receive the same amount of radiation exposure naturally received each day from the environment. (It should be noted that this naturally occurring radiation is not the same thing as food irradiation, which is a process used by humans to kill bacteria, molds, and pests to prevent foodborne illnesses and spoilage.) Overall, the levels of natural radionuclides found in our food and water are low and considered safe for human consumption by regulatory bodies.
Most surprisingly for some is the fact that other humans are also a source of exposure to one another. From birth, people have internal radiation in the form of radioactive potassium-40, lead-210, and carbon-14. These elements reside in our blood and bones. As previously noted, humans also ingest traces of naturally occurring radioactive material found in our food and water. When our bodies metabolize the non-radioactive and radioactive forms of potassium and other elements, they then contain small amounts of radiation which can act as exposures to others.
Man-Made Radiation Exposure
A more familiar source of radiation exposure to many is man-made radiation, such as procedures using X-Rays and radiation therapy to treat cancer. According to the Health Physics Society, approximately 42% of annual dose comes from man-made radiation. This percentage includes medical procedures, household products like smoke detectors, and small quantities of normal discharges from nuclear and coal power plants.
Natural background radiation has always been a part of life on earth, and it always will be. It is important to understand that this is not something to be feared. Low levels of ionizing radiation from naturally occurring sources such as space, the ground beneath our feet, and even some of the food we eat are not dangerous and do not pose a direct health risk to ourselves or our loved ones.
Note: Visit our regulatory page to learn how Versant Physics’ board-certified Internal Dose Specialists, Medical Physicists, and Health Physicists, can assist with your radiation safety program needs.
Employees who become pregnant and work with radiation or radioactive materials during their pregnancy are often concerned about the safety of doing so, as well as the potential effects of radiation on their unborn child. Occupationally exposed workers are not required to declare a pregnancy to their employer. However, if they decide to declare there are dose limits that should be observed and additional protective measures that can be taken to protect both mom and baby.
Declaring a Pregnancy
In the United States, pregnant employees who work with or around radiation have the option of declaring their pregnancy. This declaration is voluntary and informs the worker’s employer in writing of their pregnancy as well as the estimated date of conception. This information is confidential and shared only with the employer and radiation safety officer, however, it is valuable for reducing exposure and allowing for close monitoring of both the employee and the baby throughout the pregnancy.
The NRC and States require licensees and registrants (i.e., the facility the employee works at) to make efforts to limit the declared pregnant worker’s received dose. This can mean that some normal job functions may not be permitted if doing those jobs would result in the fetus/embryo receiving more than 500 mrem.
Employees also have the option to discuss with their employer or radiation safety officer about potential changes to their job status prior to declaring a pregnancy if they so choose. The option to revoke a declaration of pregnancy even if the worker is still pregnant is also available at any time throughout the pregnancy.
When an employee declares a pregnancy, they should sit down with their radiation safety officer for a one-on-one counseling session. This is a great opportunity to ask questions and address any monitoring or safety concerns that may arise.
They are then issued a fetal dosimeter in addition to their regular monitoring device, which is worn at the hip or waist level. For procedures where a lead apron is worn, the dosimeter should be worn beneath it while the regular dosimeter is worn on the outside at the neck or collar. The fetal dosimeter is monitored monthly by the radiation safety officer to ensure that the regulatory fetal dose limits are not exceeded.
According to regulations, the lower dose limit for the embryo or fetus remains in effect until the worker withdraws the declaration in writing or is no longer pregnant. If it is not withdrawn, the original declaration expires after one year.
If an employee chooses not to declare their pregnancy, the employee and her baby are restricted to the standard occupational dose limits that apply to all occupationally exposed workers. The annual total effective dose equivalent (TEDE) for the whole body is 5,000 mrem. (10 CFR Part 20.)
Occupational Exposure
In most cases, the ways in which a pregnant woman may be occupationally exposed to radiation within regulatory limits are not likely to cause adverse health effects for the developing fetus. However, most regulations are guided by the principle that any level of radiation can potentially result in negative biological effects and that the likelihood of such effects increases as the dose received increases.
The NRC requires licensees to “limit exposure to the embryo/fetus of an occupationally exposed individual to 500 mrem (5 mSv) or less during pregnancy for a declared pregnant worker who is exposed to radiation from licensed radioactive materials including radionuclides.” (10 CFR 20.1208) This lower dose limit is “based on a consideration of greater sensitivity to radiation of the embryo/fetus and the involuntary nature of the exposure.”
To break this down further, the regulations state that the radiation dose from occupational exposure should be limited to 500 mrem for the duration of the pregnancy and no more than 50 mrem per month. At this level, (1/10 the dose that a regular occupationally exposed worker may safely receive in a year) the risk of negative health effects is low.
Pregnant workers can speak directly with their radiation safety officer or on-site medical or health physicist to determine the safest dose limits for their individual needs, which may depend on their exposure history and the types of jobs they perform on a regular basis.
Undergoing Medical Procedures While Pregnant
Occupational limits for declared pregnant workers do not apply to individuals who undergo diagnostic or therapeutic procedures, such as X-rays, fluoroscopy, or radiation therapy.
According to Robert Brent, MD, Ph.D. for HPS.org, diagnostic procedures of different parts of the body, such as the head, teeth, legs, or arms do not directly expose the fetus. Modern medical imaging procedures focus the X-ray beam only on the body part of interest, and the amount of radiation that could reach the embryo or fetus during these diagnostic procedures is small and unlikely to increase the risk of miscarriage or birth defects. Most procedures expose the developing fetus or embryo to less than 50 mSv, if at all. At this level of exposure, there is no cause for concern.
Regardless of pregnancy status, the ALARA principleshould be implemented by the individual’s care team to guide decisions made about treatment and diagnostic procedures. A radiation safety officer or medical physicist can also help provide options to minimize dose. It should also be noted that those with fetal dosimeters should not wear their dosimeter during an X-ray or nuclear medicine procedure.
Conclusion
Ultimately, the decision to declare a pregnancy is that of the pregnant radiation worker. Under the current safety guidelines, the risk for adverse health effects to an embryo or fetus posed by occupational exposure or medical procedures is low. However, employees should take advantage of the resources available such as the NRC regulations, literature provided by the Health Physics Society, and the expertise of their radiation safety officer and on-site medical or health physicist.
Ionizing radiation is useful for diagnosing and treating a range of health conditions–broken bones, heart problems, and cancer, for example. Medical imaging with x-rays, diagnostic radiopharmaceuticals, and radiation therapy are often life-saving procedures.
However, the accidental or misuse of medical radiation can sometimes cause unforeseen and unfortunate consequences. Radiation protection guidelines and policies help to ensure the safe use of radiation in the medical setting for both patients and staff.
The health effects of ionizing radiation are usually classified into two categories: deterministic and stochastic.
Deterministic Effects
According to the International Atomic Energy Agency (IAEA), a health effect that requires a specific level of exposure to ionizing radiation before it can occur is called a deterministic effect. The severity of a deterministic effect increases as the dose of exposure increases and considers a minimum threshold, below which no detectable clinical effects occur. This type of effect is predictable and reproducible. For example, localized doses to certain parts of the body at increasing levels will result in the same biological effects.
Deterministic effects are caused by severe cell damage or death. Individuals who experience the physical effects of this cell death do so when it is large enough to cause significant tissue or organ impairment.
Deterministic effects are short-term, adverse tissue reactions resulting from a dose that is significantly high enough to damage living tissues. The severity of a deterministic effect increases with radiation dose above a threshold, below which the detectable tissue reactions are not observed.
Deterministic effects are usually predictable and reproducible. For example, localized doses to certain parts of the body at increasing levels will result in well-understood biological effects.
Stochastic effects are probabilistic effects that occur by chance. An extremely rare stochastic effect is the development of cancer in an irradiated organ or tissue. The probability of occurrence is typically proportional to the dose received. Stochastic effects after exposure to radiation occur many years later (the latent period). The severity is independent of the dose originally received.
Since many agents in the environment are also known carcinogens, and since many cancers occur spontaneously, it is not possible in most cases to directly link radiation exposure to an observed cancer. If a population group receives a dose of ionizing radiation at one time, it is therefore not possible to predict who in that group will develop cancer, if any, or to tell if the people who do develop cancer did so as a result of the dose of ionizing radiation or some other lifestyle factor, such as smoking.
Examples of stochastic effects include:
Cancer
Heritable or genetic changes
Dose Limits and Radiation Protection
In our day-to-day lives, we are exposed to both background and man-made sources of radiation. Everyone receives radiation exposure from natural cosmic and solar rays, and radionuclides in soil. The benefits of diagnostic and therapeutic medical radiation far exceed the risks. Fortunately, the health risks associated with natural background levels are small, and by regulations, we are protected from man-made radiation.
The National Council on Radiation Protection and Measurements (NCRP) recommends dose limits for managing exposures to ionizing radiation and protecting humans from adverse effects. Their purpose is to prevent acute and chronic radiation-induced tissue reactions (deterministic effects) and to reduce the probability of cancer (stochastic effect) while maintaining the benefits to people and society from activities that generate radiation exposures (NCRP Report No. 180, 2018).
Type of limit
Radiation worker
Public
Stochastic limits Effective dose, whole body (mSv/year)
Figure 2. Values from NCRP Report No. 180, Management of Exposure to Ionizing Radiation: Radiation Protection Guidance for the United States (2018).
The concept of dose limits also takes into account the ideas that any use of radiation should do more good than harm, and that permissible exposure should be maintained “as low as reasonably achievable” (ALARA). In line with this philosophy, medical professionals strive to minimize medical radiation exposures to patients without compromising imaging quality and therapy effectiveness.
Conclusion
Adverse health effects can occur after exposure to ionizing radiation. For radiation protection, scientific advisory organizations have recommended dose limits to prevent deterministic effects and reduce the probability of stochastic effects in radiation workers, medical professionals, patients, and other members of the general public.
The ALARA principle is a relatively simple safety protocol designed to limit ionizing radiation exposure to workers from external sources.
This principle was established by the National Council on Radiation Protection and Measurements (NCRP) in 1954 in response to the atomic bombings of Hiroshima and Nagasaki and the increased interest in nuclear energy and weaponry post-WWII. The philosophy has been refined over the years by different regulatory agencies such as the Atomic Energy Commission (AEC) and Nuclear Regulatory Commission (NRC) as more knowledge about radiation and its effects on living tissue has come to light. In its current form, ALARA stands for “as low as reasonably achievable” and is considered the gold standard for radiation protection.
ALARA is based on the idea that any amount of radiation exposure, big or small, can increase negative health effects, such as cancer, for an individual. It is also based on the principle that the probability of occurrence of negative effects of exposure increases with cumulative lifetime dose. As such, the ALARA principle is considered a regulatory requirement for all radiation programs licensed with the NRC and any activity that involves the use of radiation or radioactive materials.
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To successfully implement ALARA principles in your radiation safety program, “it is important that every reasonable effort be made to maintain exposures to radiation as far below the dose limits in this part as is practical consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest.” (10 CFR 20.1003)
Time, Distance, and Shielding
There are three factors to the ALARA philosophy which, when executed correctly, can reduce and even prevent unnecessary exposure: time, distance, and shielding.
Time
Limit the amount of time spent near a radiation source. If you must work near a radioactive source, you should work as quickly as possible and then leave the area to avoid spending more time around the source than necessary.
Distance
Increase the distance between yourself and a radiation dose. The farther away you are, the lower the dose you will receive. In many cases, the dose rate decreases as the inverse square of the distance – when the distance is doubled, the dose rate goes down by a factor of four.
Shielding
Put a barrier between you and the radiation source. The type of barrier will depend on what kind of radiation source is being emitted but should be made of a material that absorbs radiation such as lead, concrete, or water. This can also include PPE such as thyroid shields and lead vests.
Conclusion
The ALARA principle has successfully limited exposures to workers—and patients undergoing medical procedures involving radiation—for several decades. Adhering to this principle as well as your state’s radiation safety regulations will result in keeping workers healthy and protected.
Visit our website for more information on how Versant Physics’ board-certified health physicists, medical physicists, and radiation safety officers can help you implement safe practices in your radiation safety program.
We are often asked questions about applying for or changing licenses to possess and use radioactive materials. There are many different types of licenses; choosing amongst them can be confusing. In this post, we will discuss four common types.
With some exceptions, approval by a regulatory agency (U.S. Nuclear Regulatory Commission or equivalent state agency), in the form of a license, is required to use and/or dispose of radioactive materials.
The type of license authorizing the purchase, possession, use, and disposal of radioactive materials is based on several factors:
Type, form and quantity of radioactive materials requested
Proposed use(s)
Experience of the proposed licensee with managing the use of radioactive materials
Types of licenses include, but are not limited to:
Limited scope specific academic and research and development
Limited scope specific medical use
Broad scope specific
Broad scope specific medical use
In this post, we will discuss the regulations under which the U.S. Nuclear Regulatory Commission (NRC) issues two common types of licenses: (i) limited scope specific and (ii) broad scope specific. Some states, called Agreement States, have the authority under NRC regulations to issue licenses. Their regulations are equivalent to NRC regulations.
1. Limited Scope Licenses
These licenses are issued to applicants subject the following limitations:
Radionuclides
Specified chemical and physical form(s)
Possession limits
Proposed use(s)
Radiation Safety Officer (RSO)
Authorized User(s)
Location(s) of use
TheRSO’s training and experience should be applicable to and generally consistent with the types and quantities of licensed materials listed on the license. Authorized users (AUs) must have adequate training and experience with the types and quantities they intend to use (NUREG 1556, Vol. 7, Rev. 1). The applicant must submit to the regulatory agency for review and approval the specific training and experience of each proposed user and the facilities and equipment available to support each proposed use.
If the licensee wishes to change any of these limitations or add or remove an Authorized User (AU), permission must be sought from the issuing regulatory agency to amend the license.
Medical Licenses – general comments
Licensing for the use of radioactive materials to diagnose and treat human disease is subject to more complex regulations than the academic and research and development licenses described above. A wide variety of radionuclides and physical and chemical forms are used for a multitude of purposes in human medicine. Consequently, AUs and the RSO must meet specific and extensive training and experience criteria focusing on the type, form, and quantity to be used as well as the intent of the use (diagnosis vs. treatment).
radiation safety commensurate with use of radioactive materials;
administration of a radiation dose or dosage and how it is prescribed;
direction of individuals under the AU’s supervision in the preparation of radioactive materials for medical use and in the medical use of radioactive materials; and
preparation of a written directive, if required.
To be named as an AU on a medical license, the individual must satisfy one or more of the requirements outlined in Subparts D, E, F, G or H of 10 CFR 35. In general, this requirement can be met by:
being board certified in a specialty medical discipline appropriate to the intended use that is recognized by the Commission or Agreement State; or
being named as an AU on another license issued by the Commission or Agreement State for the same or similar type, form, and quantity of radioactive materials in question; or
having completed training and experience as specified in the regulations.
The RSO on a medical license must satisfy the training and experience requirements outlined in 10 CFR 35.50:
be certified by a specialty board whose certification process has been recognized by the Commission or an Agreement State; or
have completed a structured educational program as outline in 10 CFR 35.50(b); or
be a medical physicist who is certified by a specialty board recognized by the Commission or an Agreement State, has experience with the radiation safety aspects of similar types of radioactive materials for which the licensee seeks approval and has training in the radiation safety, regulatory issues, and emergency procedures for the types of use for which a licensee seeks approval; or
be a medical AU, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval and Is an authorized user, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval.
2. Limited Scope Specific Medical Licenses
A specific license of limited scope may be issued to private or group medical practices and to medical institutions. Each type, form, quantity and use and condition of use of radioactive materials as well as the RSO and AU(s) are named on the license (NUREG 1556 Vol. 9, Rev. 3). These licenses may also be issued to an entity requesting authorization to perform mobile medical services and certain non-medical activities such as self-shielded blood irradiators. Changes to any of these specifications or conditions must be requested and approved by amendment.
Research Involving Human Subjects
“Medical use” of radioactive materials includes administration to human research subjects. A license condition authorizing such research is not required if the research is conducted, funded, supported or regulated by a Federal Agency that has implemented the Federal Policy for the Protection of Human Subjects. Otherwise, the licensee must apply for and receive an amendment before conducting such research. In all cases, licensees must obtain informed consent from the human subjects and prior review and approval by an Institutional Review Board. All research involving human subjects must be conducted only with the radioactive materials listed in the license and for the uses authorized in the license (NUREG 1556, Vol. 9, Rev. 3).
Research involving human subjects may be conducted under either limited scope or broad scope specific licenses.
3. Broad Scope Specific Licenses
Broad scope specific licenses generally authorize possession and use of a wide range of radioactive materials. Because regulatory agencies grant significant decision-making authority to broad scope licensees through the license, a broad scope license is not normally issued to a new licensee. An applicant for a broad scope license typically has several years of experience operating under a limited scope license and a good regulatory performance history (NUREG 1556 Vol. 11, Rev. 1). Changes to the radiation safety program approved via in-house review and approval by the RSO and/or RSC (see below) do not appear on the license but are subject to review by regulatory agencies during routine inspections.
Title 10 of the Code of Federal Regulations (10 CFR) Part 33, “Specific Domestic Licenses of Broad Scope for Byproduct Material,” provides for three distinct categories of broad scope licenses (i.e., Type A, Type B, and Type C), which are defined in 10 CFR 33.11, “Types of Specific Licenses of Broad Scope.”
Type A
Type A licenses of broad scope are typically the largest licensed programs and encompass a broad range of uses. Licensees use a Radiation Safety Committee (RSC), radiation safety officer (RSO), and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license.
An applicant for a Type A broad scope license must establish administrative controls and provisions related to organization and management, procedures, record keeping, material control, and accounting and management review necessary to ensure safe operations, including:
establishment of an RSC
appointment of a qualified RSO
establishment of appropriate administrative procedures to ensure the following:
— control of procurement and use of byproduct material
— completion of safety evaluations of proposed uses that take into consideration adequacy of facilities and equipment, training and experience of the user, and operating and handling procedures
— review, approval, and recording by the RSC of safety evaluations of proposed uses
use of byproduct material only by, or under the direct supervision of, individuals approved by the licensee’s RSC
Because these controls and provisions have been established, the applicant may approve in-house, without requesting amendment:
Authorized Users
location of use within the confines of the physical location(s) listed on the license
changes in use of radioactive materials so long as the use is consistent with the license conditions and appropriate safety evaluations have been performed, documented, and approved by the RSC
The requirements for issuance of a Type A broad scope license are described in 10 CFR 33.13, “Requirements for the Issuance of a Type A Specific License of Broad Scope.”
Type B
Type B broad scope licensed programs are normally smaller and less diverse than Type A broad scope programs. Type B broad scope licensees use an RSO and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license. Because the RSO reviews and approves all uses and users under the license, rather than a full RSC, as established for Type A broad scope programs, the types and quantities of byproduct material authorized by the Type B broad scope license are limited to those described in 10 CFR 33.11(b) and 10 CFR 33.100, “Schedule A,” Column I. Generally, the scope of authorization for Type B licenses is limited to the experience and knowledge of the RSO.
Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.
The requirements for issuance of a Type B broad scope license are described in 10 CFR 33.14, “Requirements for the Issuance of a Type B Specific License of Broad Scope.”
Type C
Type C broad scope licensed programs typically are issued to institutions that do not require significant quantities of radioactive material but need the flexibility to possess a variety of different radioactive materials. Users of licensed material under these programs are approved by the licensee based on training and experience criteria described in 10 CFR 33.15(b). The types and quantities of byproduct material authorized by the Type C broad scope license are limited to those described in 10 CFR 33.11(c) and 10 CFR 33.100, Schedule A, Column II, again, considering the unity rule.
While 10 CFR 33.15 does not require Type C broad scope licensees to appoint an RSO, the licensee must establish administrative controls and provisions related to procurement of byproduct material, procedures, record keeping, material control and accounting, and management review to ensure safe operations. This should include the appointment of someone responsible for the day-to-day operation of the radiation safety program, such as an RSO.
Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.
The requirements for issuance of a Type C broad scope license are described in 10 CFR 33.15, “Requirements for the Issuance of a Type C Specific License of Broad Scope.”
4. Broad Scope Medical Licenses
The NRC issues specific licenses of broad scope for medical use (i.e., licenses authorizing multiple quantities and types of byproduct material for medical use under 10 CFR Part 35, as well as other uses) to institutions that (i) have experience successfully operating under a specific license of limited scope and (ii) are engaged in medical research and routine diagnostic and therapeutic uses of byproduct material (NUREG 1556, Vol. 9, Rev. 3). Typically, these are large medical centers/teaching hospitals that have a need to administer or use a wide variety of radionuclides and/or radiopharmaceuticals for diagnosis and therapy. Because these institutions have complex programs, the authority to approve changes in-house makes the program flexible and nimble.
AUs and the RSO on a broad scope medical license must meet the same criteria for training and experience as for a limited scope medical license discussed above.
Regulatory Services by Versant Physics
Our team of experienced Radiation Safety Officers can help you navigate the NRC regulations and determine which license type is appropriate for your facility. Contact sales@versantphysics.com to speak to a team member or learn more about our Regulatory services.
Any workplace, regardless of industry, can be affected by an emergency or accident. However, if your facility works with man-made ionizing radiation sources such as medical diagnostic equipment or radiopharmaceuticals, it is important you prepare for potential radiation incidents to ensure a swift and appropriate response should something occur.
Workplace radiation incidents can include:
Radioactive material spills or releases
Contamination of personnel
Malfunctioning safety controls
Lost, stolen, or orphaned radioactive material sources
Equipment leaks (ex. Industrial equipment)
Transportation incidents or accidents
Misuse of medical source materials or industrial radiographic material
While clean up methods and preventative measures will vary depending on the type and severity of the incident, how you collect and track information regarding the incident should be standard across your organization.
Identifying How the Accident Occurred
The first step in responding to a workplace radiation incident is understanding how the accident occurred in the first place. Was there any missing signage in the area where the accident occurred? Were ALARA principles being followed by all personnel? Has the equipment been properly maintained and inspected regularly? Even accidents that occur due to simple human error should be noted and tracked, especially if similar incidents happen regularly.
Identifying the Type of Radiation Exposure During an Incident
During a radiation incident, it is important to determine if and how an employee was exposed. The risk from exposure varies depending on the energy the radionuclide emits, the type of radiation (alpha, beta, gamma, x-rays), whether the exposure was external or internal (via injection, eating, drinking, etc.), how long people were near the radioactive material, and more.
Tracking this information is important because of the potential health effects that can result from radiation exposure. Exposure to low levels of radiation, such as the amount found in our environment (See Background Radiation Sources), will not typically have immediate health effects. However, it can contribute to overall cancer risk over a long period of time. Exposure to high doses of ionizing radiation can result in health problems ranging from skin burns and radiation sickness to cardiovascular disease and cancer.
Follow-Up
Sometimes the effects of a radiation incident or exposure will not be known right away. As time goes on, it can be difficult to recall the details of the incident with enough clarity to implement preventative measures. In these situations it is recommended that RSOs and EHS managers utilize an Incident Management software to not only identify and track the initial incident, but to use it to look back on what occurred when creating new policies and procedures.
Steps to Protect Against Future Exposure Incidents
Whether your facility handles man-made radiation or naturally occurring radioactive material, there are certain steps that can be taken to protect workers from future exposure after an incident has occurred.
Implement countermeasures such as time, distance, and shielding
Time, Distance, and Shielding are considered the standard measures for minimizing occupational radiation exposure. Limiting the amount of time spent around a radiation source reduces the overall dose from the radiation source. Similarly, the intensity and dose decrease the farther away a person is from a radiation source. Shielding measures including barriers made of lead, concrete, or water can provide protection from penetrating radiation such as gamma rays.
Radiation Safety Training One of the best ways to keep accidents from occurring is by training employees on the basic principles of radiation safety and the risks of mishandling radiation producing equipment or radiopharmaceuticals. It is important to provide refresher training periodically, especially in light of an incident, to ensure employees are up to date and prepared.
Regular monitoring, inspections, and facility audits/surveys are also ideal ways to eliminate radiation accidents and ensure everything is operating smoothly.
Implementing safety measures and following ALARA principles will help decrease the number of incidents that occur, however it probably won’t eliminate them entirely. To ensure the safety of both yourself and others in your facility, it is vital that radiation incidents be attended to promptly. Furthermore, it is important that such incidents be carefully recorded and tracked to prohibit the incident from occurring again. Utilizing Incident Management software is a great way to help you document accidents, emergencies, and illnesses, view trends in data to identify problem areas, and help you prepare and prevent future incidents from happening.
Versant Physics radiation safety software suite Odyssey is now offering the Incident Management module. The module, which can be used individually or in conjunction with any of Odyssey’s radiation safety modules, provides RSOs and EHS professionals the ability to monitor and track a variety of workplace incidents, including radiation safety events.
The module features a user-friendly dashboard for easy tracking and analysis. Users can also efficiently follow-up with open cases and analyze trends in reported incidents, making it easier to create a safe, compliant workplace for you and your staff.
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