Versant Physics, Author at Versant Medical Physics and Radiation Safety

21 Jul 2021

Incident Management, Inventory Tracking, Mobile Radiation Safety, Odyssey Software, Radiation Safety, Radiation Safety Officer, Radioactive Material Versant Physics 0 comment

The Mobile Radiation Safety Software Solution for the Modern RSO

Fieldwork is an essential component of radiation safety programs. From inventorying radioactive materials, machines, and equipment, to performing audits and inspections, there exists a need to capture real-time information while on the go.

Historically, this information would be recorded on paper forms and later transcribed to an electronic record or placed in a binder. Such methods are both outdated and time-consuming. Their very nature prohibits RSOs from accessing the most up-to-date records while traveling or on-site, and keeps them from streamlining effective administrative processes within their radiation safety programs.

But with the advent of mobile-optimized radiation safety software, performing these tasks and recording the results is more efficient than ever before.

In response to the growing awareness and need for such a software solution in radiation safety, Versant Physics has developed the cloud-based software Odyssey, with mobile optimization as a core focus. Users of the software can access Odyssey on their desktop or laptop computers, tablets, and mobile phones anywhere they have an internet connection.

Versant Physics’ implementation analyst, Katelyn Waters, has seen multiple Odyssey clients incorporate the software into their fieldwork.

“Clients frequently use Odyssey to perform on-site inventories of RAM, sealed sources, radioactive waste, machines, and equipment. They use tablets and cell phones to quickly pull up inventory records by location. From there, individual profiles can be viewed and edited on the go as needed.”

These inventory records are displayed as a table with a simple and searchable format convenient for reviewing information on the smaller screens of mobile devices. Tables contain links to individual profiles with buttons to easily adjust the activity of radioactive materials, update survey, inspection, or calibration due dates, or edit other profile information.

Each profile also has the option to print out a physical label for the inventory. The label can include a logo, information from the profile, free text, and a unique QR code. The QR code can be scanned to take a user directly to a profile to increase speed and accuracy during an inventory.

“The biggest benefit of the QR code system that I see is the ability to perform cradle-to-grave tracking of RAM, sealed sources, and waste containers,” says Waters. “Users can scan the QR code attached to the material throughout its lifetime to view location, activity, and ownership changes to ensure that they are always accessing accurate, up-to-date information.”

These QR codes are available to be printed for RAM, sealed sources, waste containers, machines, equipment, and laboratories in Odyssey. Utilizing the labeling tools not only helps radiation safety staff quickly access information, but also complies with FDA and NRC labeling requirements for radioactive materials, machines, and laboratory doors.

“In addition to completing inventories, we also see our clients utilize the Forms module of Odyssey for audits, inspections, and surveys,” says Waters. “Customizable forms can be created which include images like floor plans. These forms can be filled out and the images marked up using mobile devices during the inspection itself.”

The forms utilized during these inspections are custom forms set up during the implementation process by the Versant Physics team, or by an administrator. The same form can be filled out repeatedly for consistency and to track changes in responses over time. This standardization of forms is an essential aspect of radiation safety for quality control.

Another important consideration for data capture is efficiency. Odyssey aims to accomplish efficient data collection by prefilling data from its other modules into the form where applicable. This reduces the amount of time spent filling out the form and helps minimize the potential for human error as existing data does not need to be copied over.

Utilizing cloud-based software has become increasingly relevant as radiation safety programs move from paper-based methods to electronic solutions. Performing work in the field itself on mobile devices aids in getting records more efficiently into this desired electronic format. Odyssey is engineered to assist with this transition to increase data accessibility, efficiency, and accuracy for radiation safety programs.

You can schedule a live demo with our software specialists to learn more about individual Odyssey modules, mobile features, and software usability.

24 Jun 2021

Irradiation, Regulatory Versant Physics 0 comment

What is Food Irradiation?

Food irradiation is a common practice that is frequently misunderstood. Not only has the process of exposing food products to ionizing radiation, including X-Rays or electron beams, been heavily researched and utilized safely for over a century, it is a process that has proven benefits for the health of human beings.

The history of food irradiation.

The process of irradiating food began as early as 1905 when patents were issued in the U.S. and Great Britain to use ionizing radiation to kill bacteria found in foods. After World War II, research was conducted by the U.S. Army to verify the safety and efficacy of the irradiation process for meat, dairy products, fruits, and vegetables. Food irradiation has been controlled by the Food and Drug Administration since 1958 and recognized by the United Nations since 1964, when the first meeting of the Joint Expert Committee on Food Irradiation took place. It was determined by this committee in 1980 that “irradiation of foods up to the dose of 10 kiloGrays introduces no special nutritional or microbiological problems,” and the use of irradiation in the U.S. food supply was expanded by the FDA in 1986. In addition to the FDA and the UN, irradiation has been endorsed by the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the U.S. Department of Agriculture (USDA).

Why irradiate food?

There are several important reasons to irradiate food which ultimately benefit humans.

Prevention of Food borne Illness – Nobody likes having food poisoning. Food irradiation eliminates bacteria and molds like Salmonella and Escherichia coli (E. coli) which can spoil food and cause serious foodborne illnesses.

Sterilization – Irradiated foods can be used to sterilize foods which do not require refrigeration. These can be used in hospital settings for individuals with compromised immune systems or those undergoing chemotherapy. A variety of household and consumable products are also irradiated for sterilization purposes, including Band-Aids, cotton balls, medical products like surgical gloves, and even cosmetics.

Preservation – Have you ever wondered why spices have such a long shelf life, or why that bag of potatoes you bought last week is still sprout free? The answer is food irradiation. Food irradiation can extend the shelf life of certain foods by destroying organisms that cause spoilage and early sprouting.

Pest-Control – Irradiation helps control invasive insects that live in or on imported fruits and vegetables by killing or sterilizing them to prevent new bugs from infecting U.S. crops. This method is also safer than certain pest-control practices which have the potential to harm the produce through the use of toxic chemicals.

Of course, the benefits to irradiating food do not diminish the need for safe food handling practices by growers, processors, and consumers. All food should be stored, handled, and cooked appropriately. If safe handling practices are not followed, disease-causing organisms can still contaminate food and illness can occur.

It also does not completely remove all food dangers. For example, food irradiation can slow fruits and vegetables from aging, but it does not stop them. It also does not eliminate dangerous toxins that are already in food, such as Clostridium botulinum, a common bacterium which produces a toxin that causes botulism.

What kind of foods are irradiated?

In the United States, the FDA has approved a variety of foods to undergo irradiation, including:

Beef and Pork
Poultry
Lobster, Shrimp, and Crab
Fruits and Vegetables
Lettuce and Spinach
Shell eggs
Shellfish
Spices and Seasonings

The international symbol for irradiation is called the Radura. This green symbol is required to be present on food packaging of irradiated food alongside the statements “Treated with radiation” or “Treated by irradiation.” According to the FDA, bulk foods like fruits and vegetables must be individually labelled with this symbol, however it is not required for individual ingredients in multi-ingredient foods, such as spices, to be labelled. If this symbol is present, this also indicates that the food is not classified as organic no matter how it was grown or produced.

How is food irradiated?

The overall process is simple. Three different kinds of radiation are approved for use: Gamma rays, electron beams, or x-rays. Packaged or bulk food pass through a radiation beam in a radiation chamber on a conveyor belt. The ionizing radiation breaks the chemical bonds into the bacteria or mold cells, which kills or damages the pathogens enough that they cannot multiply. This process does not affect the taste or smell of the food being irradiated.

This process also does not bring food into contact with radioactive materials, nor does it make food radioactive. Irradiated food does not expose those who eat it to radiation.

Are there risks to eating irradiated food?

Eating irradiated food is not harmful and there are no radiation-related risks. In fact, irradiating foods increases the availability of healthy and nutritious food supplies on a global scale. The chemical changes to food caused by irradiation are comparable to the changes food undergoes when cooked or canned.

Safe and beneficial.

Exposing food products to ionizing radiation is a safe, heavily researched process endorsed by governing agencies around the world. It is responsible for controlling invasive insects, destroying harmful bacteria that can cause food borne illnesses, and increases the shelf-life of certain foods which allows for more widespread access to healthy, nutritious food. This process also poses no radiation-risks to the public.

Further reading:

http://hps.org/publicinformation/ate/faqs/foodirradiationqa.html

https://www.epa.gov/radtown/food-irradiation

https://ccr.ucdavis.edu/food-irradiation/history-food-irradiation

https://www.fda.gov/food/buy-store-serve-safe-food/food-irradiation-what-you-need-know

15 Jun 2021

Background Radiation, Health Effects Versant Physics 0 comment

The Truth About Background Radiation

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.

silver airplane flying above orange clouds

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.

Learn more about the health effects of man-made ionizing radiation in our blog post here.

Conclusion

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.

For more information, visit the Health Physics Society webpage, epa.gov, or the International Atomic Energy Agency.

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.

Additional Sources:

https://www.nrc.gov/about-nrc/radiation/around-us/sources/nat-bg-sources.html

https://www.cdc.gov/nceh/radiation/air_travel.html

NCRP Report 160

NCRP Report 184

20 May 2021

Health Effects, Radiation Safety Versant Physics 0 comment

Occupational Radiation Workers & Declaring a Pregnancy

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.

pregnant radiation worker consulting with radiation safety officer

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 principle should 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.

Visit our website to learn more about Versant Physics regulatory services, including radiation safety officer support, personnel dosimetry management for declared pregnant workers, and more.

Sources

https://www.cdc.gov/nceh/radiation/emergencies/prenatalphysician.htm

https://www.nrc.gov/reading-rm/doc-collections/cfr/part020/index.html

https://hps.org/hpspublications/articles/pregnancyandradiationexposureinfosheet.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3835582/

21 Apr 2021

ALARA, Health Effects, Ionizing Radiation, Radiation Safety Versant Physics 0 comment

Deterministic vs. Stochastic Effects: What Are the Differences?

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.

how to understand and communicate radiation risk diagram — **Figure 1 Radiation – Deterministic and Stochastic Effects – Image Wisely, March 2017 “How to Understand and Communicate Radiation Risk”**

Some examples of deterministic effects include:

Radiation-induced skin burns
Acute radiation syndrome
Radiation sickness
Cataracts
Sterility
Tumor Necrosis

Stochastic 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)	50	1
Deterministic limits Tissue absorbed dose (mGy/year)
Lens of the eye	50	15
Skin	500	—
Extremities (hands and feet)	500	—

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.

Versant Physics is a full-service medical physics and radiation safety consulting company based in Kalamazoo, MI. Contact us for all of your regulatory, radiation safety, and personnel dosimetry needs.

Sources:

08 Apr 2021

ALARA, Radiation Safety, Radiation Safety Officer, Regulatory Versant Physics 0 comment

ALARA: The Gold Standard of Radiation Protection

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.

Check out VersantCast Episode 3: Linear No Threshold with Dr. Alan Fellman

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.

Sources

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Author: Versant Physics

What is Food Irradiation?

The history of food irradiation.

Why irradiate food?

What kind of foods are irradiated?

How is food irradiated?

Are there risks to eating irradiated food?

Safe and beneficial.

The Truth About Background Radiation

Occupational Radiation Workers & Declaring a Pregnancy

Declaring a Pregnancy

Occupational Exposure

Undergoing Medical Procedures While Pregnant

Conclusion

Deterministic vs. Stochastic Effects: What Are the Differences?

Deterministic Effects

Stochastic Effects

Dose Limits and Radiation Protection

Conclusion

ALARA: The Gold Standard of Radiation Protection

Time, Distance, and Shielding

Conclusion

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