X-Ray risk from overexposure to radiation, danger and safety by Ray Sahelian, M.D. X-Ray Diagnosis
X-rays are a
form of electromagnetic radiation with a wavelength in the range of 10 to 0.01
nanometers, corresponding to frequencies in the range 30 to 30 000 PHz (1015
hertz). X-rays are primarily used for diagnostic radiography and
crystallography. X-rays are a form of ionizing radiation and as
such have risks and can be dangerous.
X-Ray risk
Since x-rays are a type of radiation, people undergoing these tests are
concerned that the radiation may increase their risk of cancer. It's true that
overexposure to x-rays can damage or destroy living tissue. There is a concern
that excessive exposure to x-rays can raise the risk for cancer.
Chest X-ray and Breast Cancer
Exposure to chest X-rays may increase the risk for breast cancer risk in mutation carriers. Studies have shown that young girls who receive repeated X-rays for assessment of scoliosis have an increased risk of breast cancer. Dr. David Goldgar of Case Western Reserve University in Cleveland, Ohio, and colleagues retrospectively evaluated 1601 women who were either BRCA1 or BRCA2 carriers and were exposed to routine, occasional and conventional chest X-rays for screening or diagnosis to assess risk of breast cancer. These women already have a high risk of breast cancer without the possible risk increase conveyed by chest X-rays. The IBCCS members found that any reported exposure to chest X-rays was associated with a hazard ratio (HR) of 1.54. Women 40 years old or younger had an even higher risk of breast cancer after chest X-ray exposure with an HR of 1.97. Women born after 1949 had an HR of 2.56. BRCA1/2 carriers exposed to chest X-rays before age 20 had the highest risk, with an HR of 4.64. Journal of Clinical Oncolology 2006;24:3361-3366.
Computed tomography (CT) coronary angiography raises
breast cancer risk
A special type of X-ray used to diagnose heart disease may cause cancer in women
and young adults. The procedure, called a computed tomography (CT) coronary
angiography can see inside the heart and its arteries without invading the body.
But it gives a high dose of radiation, enough to cause cancer in vulnerable
people. The CT angiography is sometimes used in emergency rooms when someone
comes in with chest pain and doctors need to assess quickly whether a heart
attack is likely.
Patients are
receiving the equivalent of 600 chest X-rays when they get CT scans for
heart disease and not
enough clinics are using known ways to reduce this exposure. While the potential
risk of developing cancer after a cardiac CT scan is slight, at less than 1
percent, researchers in a large, international study found the radiation doses
from such tests varied widely among hospitals, suggesting more can be done to
minimize patients' exposure. Dr. Thomas Gerber of the Mayo Clinic in
Jacksonville, Florida was a co-author in the study published in Jan 2009.
X-ray machine
An X-ray machine is used by radiologists to obtain an x-ray image. X-ray
machines are used in various fields, mostly in medicine and security.
Excess radiation exposure
Younger Americans are being exposed to high amounts of radiation from medical
scans that increase their risk of cancer. The cumulative risk of repeated
exposure to radiation from medical scans is a public health threat that needs to
be addressed. Dr. Reza Fazel of Emory University in Atlanta did a three-year
study of nearly 1 million Americans aged 18 to 64. It reveals that as many as 4
million Americans a year are exposed high doses of radiation. The findings heap
new pressure on imaging equipment makers such as General Electric Co, Siemens AG
and Philips Electronics NV, already facing efforts in Congress to cut payments
for imaging procedures as a way to find money to expand U.S. health insurance
coverage. A report in March 2009 by the National Council on Radiation Protection
and Measurement found that Americans are exposed to seven times more radiation
from diagnostic scans than in 1980. The two biggest contributors to radiation
exposure were an advanced kind of X-ray called a computed tomography or CT scan
and nuclear medicine scans -- in which a small amount of radioactive material is
injected into the bloodstream and read by special cameras. One of the nuclear
medicine procedures, an advanced heart stress test called a myocardial perfusion
scan, is the single-biggest contributor. "It was easily the procedure that
accounted for the greatest proportion of the overall radiation exposure," Dr.
Reza Fazel said. Most procedures were done in outpatient settings such as
doctor's offices instead of a hospital. New England Journal of Medicine, August
27, 2009.
Questions received by email
I'm a flight attendant with a quick question. I routinely carry with me BHRT
meds, bioidentical hormone replacement therapy, as well as vitamins which are
placed through the X-ray machines at airports all over the world. Does this
affect the efficacy of these pills and estrogen creams?
I don't have any reason to believe the weak radiation would
have any effect or cause any damage.