How do x rays cause cancer

Based on animal and human evidence, several expert agencies have evaluated the cancer-causing nature of x-rays and gamma rays. Its major goal is to identify causes of cancer.

The US Environmental Protection Agency EPA sets limits for exposure to x-rays and gamma rays in part because it recognizes that this form of radiation can cause cancer. For more information on the classification systems used by these agencies, see Known and Probable Human Carcinogens.

The American Cancer Society medical and editorial content team. Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing. Cancer consequences of the Chernobyl accident: 20 years on.

J Radiol Prot. Environmental Protection Agency. Radiation Protection: Health Effects. Accessed at www. Food and Drug Administration. International Agency for Research on Cancer.

Leukemia incidence in the Russian cohort of Chernobyl emergency workers. Radiat Environ Biophys. Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin. Risk of cancer and non-cancer diseases in the atomic bomb survivors. Radiat Prot Dosimetry. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study.

Dental x-rays and risk of meningioma. Epub Apr American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy. Download this topic [PDF]. What do the studies show? Atomic bomb survivors Much of what we know about cancer risks from radiation is based on studies of the survivors of the atomic bombs in Nagasaki and Hiroshima.

Studies have found an increased risk of the following cancers from higher to lower risk : Most types of leukemia although not chronic lymphocytic leukemia Multiple myeloma Thyroid cancer Bladder cancer Breast cancer Lung cancer Ovarian cancer Colon cancer but not rectal cancer Esophageal cancer Stomach cancer Liver cancer Lymphoma Skin cancer besides melanoma For most of these cancers, the risk was highest for those exposed as children, and was lower as the age at exposure increased.

Chernobyl accident Children and adolescents living near the Chernobyl plant at the time of the accident had an increased risk of thyroid cancer linked to exposure to radioactive iodine.

Nuclear weapons testing Studies suggest that some people who were children during the period of above ground nuclear testing in the US may develop thyroid cancer as a result of exposure to radioactive iodine in milk.

Keep track of your x-ray history. It won't be completely accurate because different machines deliver different amounts of radiation, and because the dose you absorb depends on your size, your weight, and the part of the body targeted by the x-ray. But you and your clinician will get a ballpark estimate of your exposure.

Consider a lower-dose radiation test. If your clinician recommends a CT or nuclear medicine scan, ask if another technique would work, such as a lower-dose x-ray or a test that uses no radiation, such as ultrasound which uses high-frequency sound waves or MRI which relies on magnetic energy.

Consider less-frequent testing. If you're getting regular CT scans for a chronic condition, ask your clinician if it's possible to increase the time between scans. And if you feel the CT scans aren't helping, discuss whether you might take a different approach, such as lower-dose imaging or observation without imaging.

Don't seek out scans. Don't ask for a CT scan just because you want to feel assured that you've had a "thorough checkup. And there's a chance the scan will find something incidental, spurring additional CT scans or x-rays that add to your radiation exposure. Measuring radiation If you mention the measurement of radiation, many people will recall the classic Geiger counter with its crescendo of clicks.

Average effective dose mSv. Range reported in the literature mSv. However, the part of your body being examined will only be exposed to a low level of radiation for a fraction of a second. Generally, the amount of radiation you're exposed to during an X-ray is the equivalent to between a few days and a few years of exposure to natural radiation from the environment.

Being exposed to X-rays does carry a risk of causing cancer many years or decades later, but this risk is thought to be very small. For example, an X-ray of your chest, limbs or teeth is equivalent to a few days' worth of background radiation, and has less than a 1 in 1,, chance of causing cancer.

For more information, see GOV. UK: patient dose information. The benefits and risks of having an X-ray will be weighed up before it's recommended. Talk to your doctor or radiographer about the potential risks beforehand, if you have any concerns.

Page last reviewed: 13 July Next review due: 13 July How X-rays work X-rays are a type of radiation that can pass through the body. When X-rays are used X-rays can be used to examine most areas of the body. Problems that may be detected during an X-ray include: bone fractures and breaks tooth problems, such as loose teeth and dental abscesses scoliosis abnormal curvature of the spine non-cancerous and cancerous bone tumours lung problems, such as pneumonia and lung cancer dysphagia swallowing problems heart problems, such as heart failure breast cancer X-rays can also be used to guide doctors or surgeons during certain procedures.

Preparing for an X-ray You don't usually need to do anything special to prepare for an X-ray. Having an X-ray During an X-ray, you'll usually be asked to lie on a table or stand against a flat surface so that the part of your body being examined can be positioned in the right place. This is because it can affect our cells and damage our DNA.

Ionising radiation is different to the radiation given off by mobile phones, 4G and radios. We are naturally exposed to a small amount of ionising radiation every day. The main source in the UK is radon gas from the ground. There are also man-made sources of ionising radiation, including x-rays. To help avoid the possible health effects of ionising radiation, man-made exposures are tightly regulated in the UK.

There is evidence that radiation from medical imaging such as x-rays slightly increases the risk of cancer. About 6 in 1, cancers in the UK are linked to this type of radiation. But the health risks are much lower than the risks of medical conditions if they are not diagnosed and treated correctly. Medical x-rays and other types of imaging are very important to help diagnose different illnesses — from broken bones to cancer.

Other types of imaging that use ionising radiation include mammography used for breast screening and fluoroscopy e. The amount of radiation from medical imaging is usually less than we would be exposed to naturally over time.