For example, people living at high altitudes, who are exposed to more natural background radiation from cosmic rays than people living at sea level, do not have noticeably higher cancer rates. 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.
For most of these cancers, the risk was highest for those exposed as children, and was lower as the age at exposure increased. 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.
Workers employed in cleanup operations from 1986-1990 had an increased risk of leukemia (all types). These individuals had higher and more prolonged radiation exposures that the population residing around the plant.
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. Studies of these patients have helped us learn about how radiation affects cancer risk.
Peptic ulcer disease: A large study of people who were treated with high doses of radiation (an average of 15 GY or 15,000 MTV) for the treatment of peptic ulcers found a higher risk of cancer of the stomach and pancreas. Ringworm of the scalp: Studies of people who were treated with radiation to treat a fungal infection of the scalp (called scalp ringworm or Tina wapitis) have found an increased risk of basal cell skin cancers.
The risks of some other cancers, such as breast, liver, kidney, bladder, and other sarcomas, may also have been increased. Children treated with radiation to this area also have an increased risk of thyroid cancer.
The risk of cancer depends on a number of factors, include the dose of radiation, the part of the body being treated, the age of the person getting it (younger people are generally at greater risk), and the use of other treatments such as chemotherapy. Other factors might also play a role in how likely a person exposed to radiation is to develop cancer.
For example, some genetic conditions can mean that a person’s cells are more vulnerable to radiation damage, which might in turn raise their risk more than in someone without these gene changes. Some studies have estimated the risk of radiation exposure from imaging tests based on the risks from similar amounts of radiation exposure in the studies of the atomic bomb survivors.
Based on these studies, the US Food and Drug Administration (FDA) estimates that exposure to 10 MTV from an imaging test would be expected to increase the risk of death from cancer by about 1 chance in 2000. Studies of women who had been imaged many times with fluoroscopy as a teenager or young woman during treatment for tuberculosis have found an increased risk of breast cancer years later.
Teenagers and young women who had many x-rays of the spine to monitor scoliosis have been found to have an increased risk of breast cancer later on. It found that the people who had the tumors were more likely to have had a type of dental x-ray called a bite-wing, and to have had bite-wing or Andrew x-rays every year.
A study in England of exposure to radiation from CT scans found that children who received a dose of at least 30 may (the same as 30 MTV) to the bone marrow had 3 times the risk of leukemia compared to those who received a dose of 5 may or less. Several agencies (national and international) study different substances in the environment to determine if they cancausecancer.
The American Cancer Society looks to these organizations to evaluate the risks based on evidence from laboratory, animal, and human research studies. Based on animal and human evidence, several expert agencies have evaluated the cancer -causing nature of x-rays and gamma rays.
The National Toxicology Program (NTP) is formed from parts of several US government agencies, including the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA). 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 cancausecancer.
Most of the evidence linking high levels of radiation exposure to cancer comes from studies of specific groups of people, such as those who survived atom bomb blasts in Japan during World War II, survivors of the Chernobyl nuclear accident in the Soviet Union in 1986, and individuals such as uranium miners and nuclear power plant workers whose jobs entail exposure to high amounts of radiation. X-rays are also used in a variety of technologies such as cancer treatment and, at much lower levels, in medical and dental imaging, food irradiation, and airport screenings.
Fluoroscopy, which uses X-rays to make moving images of internal body structures, exposes patients to different amounts of radiation depending on the duration of the test. As a treatment for cancer and other diseases, X-rays and other forms of radiation have a long history, stretching back to the early 20th century, when German and French researchers discovered that X-rays could in some cases shrink or obliterate tumors.
Not long afterward, however, it was found that exposure to X-rays, particularly at high doses for an extended period of time, could also cause cancer. Over the past 100 years the safety of radiation therapy has improved markedly as technologists have devised ways of aiming radiation beams with extreme precision, delivering high doses directly to a tumor while minimizing the amount reaching surrounding tissue.
For people who weren’t exposed to high levels of radiation as children, any increased cancer risk from standard medical or dental X-ray tests is probably very low. But because the level of that risk isn’t definitively known, experts advise keeping one’s exposure to medical radiation as low as possible.
Until we do, we’ll be funding and conducting research, sharing expert information, supporting patients, and spreading the word about prevention. Q. I am currently receiving annual chest CT scans to check for hidden lung cancer (I used to be a heavy smoker).
Radiation from CT scans is a bigger concern for children and young adults, who have more time to develop cancer after exposure to medical x-rays. Medical tests that involve X-rays generally expose us to only small amounts of radiation.
However, many common imaging tests use very low doses of radiation and pose only a minimal risk when performed properly. X-rays have saved millions of lives by helping doctors diagnose, monitor, and treat many medical conditions.
Studies have not found an increased risk of cancer in people who’ve received very low doses of radiation. 0.1 MTV, comparable to 10 days of natural background radiation Extremity X-ray.
CT scans create 3-D pictures that allow doctors to view your organs and other tissues. They use higher doses of radiation than most other types of imaging tests, leading to an increased risk of cancer.
Experts agree that while the benefits are worth the risk, CT scans should be ordered only when medically necessary and no other lower-radiation alternatives exist. The effective doses from diagnostic CT scans are estimated to range from 1 to 10 MTV, which is comparable to a few months to several years of background radiation.
Dental professionals also take extra measures to limit the exposure to other parts of your head and neck by using special collars and shields. A dye is consumed or injected before the test to create a more detailed outline of your organs, arteries, and joints.
The radiation dose used during fluoroscopy is higher than many other tests because it uses continuous X-ray beams over an extended period, typically 20 to 60 minutes. Fluoroscopy of the kidneys, ureters, and bladder uses 15 MTV, which is equal to approximately 5 years of background radiation.
Carefully weighing the risks and benefits and only ordering tests that are considered medically necessary opting for tests with the lowest radiation dose or finding alternatives when possible using the lowest amount of radiation possible to get the required view minimizing the length of fluoroscopy using digital X-ray technology and X-ray beam filters limiting the area being X-rayed or scanned to the smallest possible placing shielding devices on your body to protect your organs Ultrasound is often used to examine the abdomen and pelvis, breasts, soft tissues, and testes.
Exposure to X-rays and gamma rays can lead to cancer, but medical imaging procedures have a relatively low risk. The risk of death from cancer caused by 10 MTV from an imaging test is estimated at 1 chance in 2000.
To back such claims only “serves to alarm and perhaps harm, rather than educate,” they note, as they conclude that the LNT model “should finally and decisively be abandoned.” We Americans are the most over-X-rayed people on earth, and the heavy doses of radiation we get are a major, and growing, cause of cancer.
It would be pulled off the shelves so fast your head would spin, and there would be no talk of balancing the dangers with the benefits (which happen to be enormous for this supplement). The total amount of X-radiation we receive went up six times from 1990 to 2006, according to the National Council on Radiation Protection and Measurement (2009, Report 160).
The New England Journal of Medicine says CT scans alone account for half the medical imaging dose we get. The article estimates that CT scans cause something like four out of every thousand cancers (Issue 357).
The number of patients getting very high doses doubled every year from 1996 to 2010, says the Journal of the American Medical Association. A recent study of people who had cancer when they were children demonstrates the dangers of radiation.
The findings, published in the Journal of the American Medical Association, are based on detailed physicals conducted on 1,700 adults who were treated for cancer at St. Jude’s Children’s Research Hospital in Memphis from ten to 40 years ago. The researchers found that the parts of the body treated then are precisely the ones that are falling apart now.
There’s strong evidence that conventional cancer treatments accelerate the aging process of organs. Adult survivors who received radiation to the brain as children suffer from thinking and memory problems typical of much older people.
For this group of people whose average age was 33, “the health problems were considered striking” (the Wall Street Journal’s choice of words, not mine.) One is that alternative treatments could have done the job gently, with no damage, instead of the lifetime health problems these young people now face.
When I was young, I had many chronic health problems myself and received tons of X-rays, so this is personal with me. My health problems were mostly due to the Standard American Diet (SAD), consisting of sugar and other refined carbs, hormone-and-drug-fed beef and chicken, heaven knows what preservatives and other chemicals, over-cooked vegetables, no fiber and a desperate lack of nutrients.
A recent study at the University of Hong Kong found that the risk of soft-tissue sarcoma is doubled if a person receives an amount of radiation equivalent to two CT head scans. Yup, I had a brain scan, too, for those mystery headaches I used to have, plus a full set of sinus X-rays.
A child exposed to just two or three scans faces three times the risk of developing brain cancer later in life. As one of the causes he cited the harmful effects of radiation from sources like dental X-rays and mammograms.
One of the strongest voices against our X-ray mania was the late Dr. John Goffman, M.D., Ph.D. and Professor at the University of California at Berkeley. In this 700-page tome, he presented strong evidence that medical X-rays not only play an important role in causing half of all cancer cases, but also cause 60 percent of heart disease cases.
Check your home and, if possible, your work place to ensure you’re not being irradiated every day without even knowing it. As bad as medical X-rays are, radon accounts for an enormous portion of the public’s exposure to radiation.