Category: Background Radiation

10 Sep 2021
Ore mining

What is Naturally Occurring Radioactive Material?

Naturally Occurring Radioactive Materials (NORM) are just that: materials of natural origin that contain radioactive materials. NORM is found in rock formations, soil, and sand that come out of the Earth’s crust and mantle. This includes elements like radium, uranium, thorium, and potassium, as well as their decay products radium and radon. Many of these elements show up in concentrated areas, like uranium ore bodies, which are then mined for human use.

The Environmental Protection Agency (EPA) defines NORM as “materials that contain any of the primordial radionuclides or radioactive elements… that are undisturbed as a result of human activity.”

Cosmogenic NORM, or cosmic radiation produced by cosmic rays interacting with the Earth’s atmosphere, affects frequent flyers and those who live at higher altitudes.

Learn more about background radiation in our blog post here.

According to the IAEA, the activity concentrations of the radionuclides found in these places are generally low and not considered to be a risk to human health and safety.

Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM)

Human activities such as extraction and processing can expose, disturb, or concentrate NORM. Bringing natural resources from below the ground—in a solid, liquid, gas, or sludge form—and introducing it to the surface brings up the materials that contain radionuclides. When something like this happens, NORM is classified as Technologically Enhanced Naturally Occurring Radioactive Materials or TENORM.

pile of raw coal

It can also concentrate it in some cases. For example, coal-ash, a byproduct of burning coal, contains a higher concentration of NORM than it did when it was mined from the ground. As ash only accounts for about 10% of the weight of unburned coal, the resulting NORM is 10x that of the plant’s coal fuel.

Industries that generate TENORM include:

  • Mining (hard rock/metal, rare earths, uranium, copper, alumina)
  • Energy (oil and gas, coal, fracking)
  • Water treatment (drinking water, wastewater, fish hatcheries)
  • Consumer products (fertilizer, cigarettes, granite countertops, bricks/building materials)
  • Recycling

Region and geology are major factors in the amount of radioactivity and materials such processes can introduce into the environment. When these materials are exposed or concentrated because of industrial processes, humans are exposed to the ionizing radiation they give off. This can result in potential health risks including cancer.

Regulating NORM/TENORM

Radiation levels from NORM are not considered hazardous in the United States.  Therefore, it is not regulated at the federal level.

TENORM is also not regulated by the federal government or the Nuclear Regulatory Commission. It is up to individual states if and how they choose to regulate generation and disposal. Currently, there are 37 Agreement States which regulate NORM within their borders. There is little consistency among different industries and countries regarding NORM. Contact your state’s radiation management branch for more information.

How to Minimize TENORM Exposure

From a radiation safety perspective, some precautions can be taken by professionals and the public to ensure minimal exposure to these radioactive materials. The level of exercised caution ultimately depends on the type of TENORM present. In general, TENORM should be handled only by individuals familiar with radiation safety practices and hazardous industrial substances. Other steps to take include:

  • Implementing a radiation safety program
  • Using appropriate shielding, HEPA filters, and personal protective equipment as necessary
  • Minimizing time spent around TENORM
  • Avoiding eating or drinking around TENORM
  • Minimizing activities like cutting or grinding which can generate dust containing TENORM
  • Properly disposing of TENORM-contaminated waste
15 Jun 2021

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:

diagram of radon gas infiltrating a house

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

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Permits

THE PERMISSION SYSTEM FOR INVENTORY TRACKING, MACHINE MANAGEMENT & EQUIPMENT CATALOG MODULES

Permit Profile

Each permit has a dedicated profile of information that includes authorized personnel, radioactive material, machines, and devices. Permit conditions, completed audits, and forms are also found on this profile.

Authorized Condition Database

Create and view authorized conditions included on permits. Previously created authorized conditions are listed with their code, category, and description.

Permit Enforcement

Information specified on a permit not only serves as a record of that permit, but also controls what can be added to other modules. The location, owner and type of radioactive materials, machines, and equipment can be enforced by permits.

Permit Audits

Perform permit audits, mail the results to relevant personnel, and track responses to non-compliances.