Radiation is a normal part of our everyday lives. We encounter it as cosmic rays hit the atmosphere all the time. Trace amounts of radiation are found in the food we eat and the water we drink. We even receive it from the ground itself as radioactive gases are emitted from the earth´s crust in the form of radon gas.
One aspect of the IAEA´s work is to look at the amounts of radiation that workers and the general public receive in different settings, and to set standards and good practices to protect against possible overexposure. Currently, the fastest growing source of radiation exposure can be found in medicine, where the use of x-rays, particularly in computed tomography (CT) scans, are being applied with greater frequency. And while there are clear human health benefits drawn from the use of ionizing radiation in medicine, the IAEA and peer organizations are working to make sure that patients and doctors are well aware of proper radiation protection measures.
A major outcome of this project is the development of a Radiation Protection of Patients (RPOP) website, a resource dedicated to informing the public about all aspects of radiation in medicine. New information for patients recently added to the RPOP site discusses radiation protection as it relates to x-rays or radioactive substances used in medicine with special attention to CT scans, pregnancy and child care, as well as radiotherapy in cancer and interventional procedures such as cardiac catheterization for angioplasty. People who are undergoing any type of diagnosis or treatment involving ionizing radiation are encouraged to explore the RPOP site to learn about the benefits and risks related to radiation in medicine.
The Safety of Security Screening
The IAEA has also been examining radiation protection as it relates to security screening, particularly air travellers. In light of the recent unsuccessful Christmas Day 2009 terrorist attempt to detonate a bomb on a transatlantic flight, enhanced security measures are being implemented at several airports. Among the steps taken are to increase the use of scanning technology which can expose concealed objects cloaked beneath a passenger´s clothing.
There are two distinct scanning technologies that use ionizing radiation currently in broad deployment at airports: backscatter and transmission systems. Backscatter technology can detect objects hidden beneath clothing, while transmission x-rays can probe even further, producing images of swallowed objects or those hidden in body cavities. These two technologies make for high-quality, three-dimensional still pictures in roughly half a minute.
Both backscatter and transmission x-ray scanners irradiate those being scanned, but the radiation doses are extremely small. Backscatters typically dispense a radiation dose of 0.1 µSv (microsievert) per scan, while transmission x-ray machines give off 5 µSv per scan. To provide perspective, the annual average amount of radiation that each individual receives from natural background radiation is 3000 µSv.