Scientists don’t yet understand what causes most cases of leukemia to develop. However, they have identified several risk factors that can increase a person’s chances of developing this condition. Radiation exposure is one of these possible risk factors.

Although sources of both natural and human-made radiation are all around us, most people are exposed only to low levels throughout their lifetime. However, some people may come into contact with higher doses of radiation, which increases their risk for leukemia — as well as their risk for other types of cancer including lymphoma, multiple myeloma, thyroid cancer, lung cancer, and breast cancer.

How Can Radiation Lead to Leukemia?

Radiation can damage the genes found in cells, and this in turn can cause cells to turn cancerous.

What Is Radiation?

Radiation consists of waves of energy. It moves outward from the source that emits it.

Radiation can come in many forms, including heat or light. However, ionizing radiation is the type that can increase a person’s risk of cancer. Ionizing radiation includes high-energy waves or particles that can cause changes within molecules. When ionizing radiation interacts with DNA (the molecules that contain a cell’s genes), it can cause changes or mutations in the genes.

Radiation and Leukemia

Leukemia, like other forms of cancer, can develop when gene changes occur within cells. Different types of leukemia form after these changes occur within different types of blood cells.

Acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL) develop from lymphoid cells, which include B cells and T cells.

Acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) develop when gene changes occur within myeloid cells, white blood cells (like neutrophils, basophils and eosinophils cells), and occasionally in red blood cells or megakaryocytes (cells that make platelets).

Where Does Radiation Come From?

Different sources give off radiation. People may be exposed to radiation from medical procedures, other human-made sources, or the natural environment. Some sources of radiation may be easier to avoid than others.

Medical Sources of Radiation

Radiation is used during the diagnosis and treatment of several different types of health conditions. There are several imaging tests that doctors use to get a closer look at internal organs and tissues that rely on low doses of radiation.

These tests may include:

• X-rays
• Bone scans
• Computed tomography (CT scans)
• Positron emission tomography (PET scans)

These tests typically produce minute amounts of radiation. Even so, if the tests are repeated many times in the course of a person’s treatment, over time the effects of a little radiation exposure may equate to those seen with a lot of radiation exposure.

Another source of medical radiation is radiation therapy, commonly used as a cancer treatment. Radiation therapy often involves one or more sessions in which a machine aims beams of radiation at a tumor. Alternatively, some cancers may be treated with internal radiation therapy, which entails delivering radioactive material into the body, near cancer cells.

Radiation-based tests or treatments may slightly increase one’s risk of developing leukemia or another cancer. However, they can be very effective at diagnosing or treating current medical conditions.

Human-made Sources of Radiation

Some jobs require people to work with radiation. For example, people who administer medical imaging tests, work in a uranium mine, or are employed at a nuclear power plant are exposed to radiation. People in these occupations may have a higher risk of developing cancer.

Some people are exposed to radiation through certain consumer products. Cigarettes and other products that contain tobacco typically give off some radiation, so using these products regularly increases one’s exposure to radiation.

Additionally, some materials used for constructing homes or buildings contain radon. Radon is a naturally occurring radioactive element found within the Earth. Construction materials that contain this element may give off low levels of radiation that could slightly increase leukemia risk.

Nuclear weapons are among the most significant human-made sources of radiation. Many atomic bomb survivors developed different forms of cancer after these weapons were used in Japan during World War II. Additionally, many countries have tested nuclear weapons. People who work at or live near testing sites may have been exposed to radiation that could lead to an increased risk of leukemia.

Although nuclear power plants give off very low levels of radiation, an accident at one of these facilities could lead to higher levels of radiation. However, such events are very rare.

Natural Sources of Radiation

Small amounts of radiation exist all around us. This type of radiation — called background radiation — can’t be avoided, and it does not likely account for many cancer cases.

Cosmic rays are one source of background radiation. Cosmic rays are tiny particles from outer space. Some cosmic rays may reach the Earth’s surface, while many are blocked by the Earth’s atmosphere. People who spend more time higher up within the atmosphere — including those who work on airplanes and those who live at higher altitudes — may be exposed to cosmic rays more often.

Some radioactive substances are naturally found in the ground and in rocks. Occasionally, they may come into contact with food or water sources, which then would contain tiny amounts of radiation.

Radioactive radon gas is found at low levels in the outdoor air and may be present indoors in homes or office buildings.

Reducing Your Radiation Exposure

Everyone is exposed to some radiation throughout their lives. However, there may be steps you can take to minimize this exposure and lower your risk of leukemia.

Many medical imaging tests use less radiation than they used to. However, for certain higher risk populations (such as children), doctors may suggest undergoing a different type of test or using a lower radiation dose in order to minimize cancer risk.

If you need to undergo a medical procedure that involves radiation, ask your health care team about the long-term effects, both positive and negative. Usually, the benefits are worth the potential risks.

If your job requires you to be exposed to radiation, you will likely be taught safety precautions. You also may be required to participate in a workplace monitoring program to track how much radiation you come into contact with. Make sure to follow any workplace guidelines to ensure your safety.

It’s difficult to limit your exposure to most sources of background radiation. However, you can check for high radon levels within your home or workspace using testing kits, which are available online or at home improvement stores. If you detect elevated levels of radon, you can hire a licensed professional to implement a radon-reduction system. This may involve improving the building’s ventilation or insulation.

Talk With Others Who Understand

On MyLeukemiaTeam, the social network for people with leukemia and their loved ones, nearly 10,000 members come together to ask questions, give advice, and share their stories with others who understand life with leukemia.

Are you worried about health risks related to radiation? Share your experiences in the comments below, or start a conversation by posting on your Activities page.