Docs Exposed to Radiation: Their Bodies React
Reported August 26, 2011
(Ivanhoe Newswire) — Cardiologists who perform heart procedures using X-ray guided catheters are exposed to high levels of ionizing radiation. A new study offers the first evidence that these constant, high levels of exposure can cause cell level changes that might be the body’s way of protecting itself.
Researchers studied 10 interventional cardiologists who were regularly exposed to X-rays and compared them to 10 health workers who were not exposed to radiation. They obtained information about the doctors’ exposure from radiation badges, and their lifetime exposure calculated from these data.
Results showed levels of two chemicals increased in the interventional cardiologists. These chemicals were glutathione, which is an anti-oxidant that protects against cell damage from oxygen-containing molecules, and hydrogen peroxide, which indicates the amount of oxidative stress caused by these molecules. Also, lymphocyte cells showed increased levels of an enzyme called caspase-3, which is involved in programmed cell death (apoptosis) and indicates an increased susceptibility of these cells to apoptosis.
The scientists believe these changes suggest that the radiation was inducing potentially harmful effects at the cellular level, but this prompted a protective response, which could be the body’s way of killing off damaged and potentially cancerous cells.
“Our findings clearly emphasize, for the first time, that exposure to a level of radiation, which is considered ‘safe’ by regulatory standards for interventional cardiologists, can induce a profound biochemical and cellular adaptation whereby increases in the levels of reactive oxygen species in these workers are balanced by an improvement in antioxidant defenses. We also observed an increased susceptibility of lymphocytes to apoptosis, which may represent a compensatory mechanism to efficiently remove genetically damaged cells,” first author of the study, Dr. Gian Luigi Russo, a senior research scientist at the CNR’s Institute of Food Sciences in Avellino (Italy), was quoted as saying.
About 23 million people worldwide are exposed to ionizing radiation in their professions. About 7 million are medical workers. Over the past 20 years, exposure to radiation among interventional cardiologists has increased because the number of X-ray guided procedures has increased.
“Each procedure involves a large radiation exposure to the patient, which may range from the equivalent of 300 to 5,000 chest X-rays and more, with an average dose of 750 chest X-rays for a percutaneous coronary intervention or a cardiac radiofrequency ablation. Interventional cardiologists must work close to the source of X-rays, and this explains why their own professional exposure is three-times higher than that of radiologists, and can be equivalent to the dose of 250 chest X-rays per head per year. After 30 years of work, this corresponds to a lifetime’s increased risk of developing cancer of approximately one in 100, although there is still some uncertainty in these risk estimates,” Dr. Eugenio Picano, director of the Institute of Clinical Physiology at the Italian National Research Council in Pisa, Italy, was quoted as saying.
The study authors suggest interventional cardiologists should make every effort to minimize their exposure to ionizing radiation but should not be afraid of the life-saving therapy.
SOURCE: European Heart Journal, August 2011
