Bruce Banner, better known as The Hulk, should have known better than to mess with gamma radiation without x-ray protection! X-rays were discovered in 1895 by German physicist Wilhelm Conrad Rontgen; one year later, Gamma radiation was discovered by French physicist Henri Becquerel. Although these radiations are sometimes used synonymously, they are very different. Exposure to them is the same and they react the same way to certain elements; however, the Environmental Protection Agency (EPA) indicates that the difference is in atomic structure. Gamma rays originate in the nucleus, while X-rays originate in the surrounding electron fields.
History of X-ray Protection
In 1907, Rome Vernon Wagner was attending a meeting with the American Roentgen Ray Society. He proposed that he would carry a photographic plate in his pocket and develop the film at night to determine if he had been exposed to the radiation he worked with. It took until the 1920's for this invention, the film badge, to become a standard in radiation monitoring.
Eventually, the understanding of how radiation works became the ultimate protection. The EPA delineates the three main concepts behind protecting against radiation as time, distance and shielding.
Why Lead Shielding?
Many people like to cite the density of lead as the reason why radiation can't penetrate it. That really isn't the reason at all. Lead has a high atomic number and is, atomically speaking, densely filled with electrons surrounding the nuclei. The X-rays hit the lead, pass into it, and are stopped from continuing forward by those electrons. Thus, the thicker the lead, the more radiation that can be stopped; similarly, high-powered radiation requires more lead to stop it. As the radiation is stopped, heat is generated and dissipated, thus nullifying the radiation entirely.
X-rays do not shoot out in a perfect beam. The radiation scatters as it is launched into the body. Specific areas in the body, such as organs in the trunk area of the body — especially the gonadal area — are more susceptible to radiation than other areas, i.e. brain and active bone marrow. This is why lead aprons are worn to protect specific areas of the body.
X-ray versus Gamma
Both of these rays are identical in their ability to be applied in medicine, and both require the same safety requirements when used. RadSource compares the two types and reports that x-ray technology is simply more cost effective. Gamma has a longer half-life, must be stored for decades when it becomes ineffective and requires special federal licensing to use.
X-ray protection is required wherever X-rays are used. It is not a good idea to take shortcuts when dealing with radiation, since radiation can last upwards of 70 years in the body. Med techs who use X-ray equipment daily are at risk, but not if they use the proper protective gear and stay behind the barrier whenever possible.