Radioresistance is defined as the ability of some organisms to survive in environments where there is a high level of radioactivity. There may be naturally occurring radiation from uranium ores or man-made radiation from nuclear bombs or nuclear accidents. After the Chernobyl accident in Ukraine, scientists were surprised to find that many species survived when the assumption was that the high level of radiation should have killed most of them.
Ionizing radiation damages DNA in living cells. All cells have DNA repair machinery. If there is a way to accelerate the repair of DNA, it would confer some protection against the damage caused by ionizing radiation.
There is a type of bacteria named Deinococcus radiodurans (Latin for “terrific berry that withstands radiation”) that is very resistant to damage by ionizing radiation. It is known as an extremophilic bacterium meaning that it is very tough. In addition to being able to withstand radiation it can also survive dehydration, extremely low temperatures, some acids and even vacuum.
There are no drugs licensed to treat any acute radiation damage to internal tissues. Sometimes, iodine tablets are taken with the intent of flooding the system with non-radioactive iodine so that the radioactive isotope iodine-131 will not be taken up by the thyroid and cause cancer.
Protective clothing has been developed for people who work around radioactive materials on a regular basis or who might be called to respond to a nuclear accident where radioactivity has been released into the environment.
Radioactive materials are widely used in our high-tech society. There are medical application, industrial applications, research applications, nuclear power plants and nuclear weapons development. In addition, there is a great deal of radioactive waste left over from past uses. What can be done to protect people from the harmful effects of ionizing radiation?
Radiation is used to treat many different cancers. About one half of the new invasive cancer cases will be treated with radiation. The procedures and equipment have been developed to optimized damage to the cancerous tumors and tissue with minimal damage to surrounding healthy tissue. When a beam of radiation is directed at a tumor, the normal tissue in the path of the beam can be damaged.
Skin can be damaged by exposure to radioactivity either by accident or by medical treatments involving radioisotopes. Some of the symptoms accompanying radiation exposure include redness, swelling, numbness, itching, tingling, dryness, peeling, changes in color, loss of hair, thinning, hardening and open wounds. The natural healing capability of the human epidermis can deal with some radiation damage.
There a number of different websites that monitor radioactivity at various locations in the U.S. and around the world in real-time. There was an explosion of new websites after the Fukushima disaster but some of them have already disappeared. Here is a list of some of the monitoring websites that are currently active. (Several of these have been detailed in previous posts on this blog.)
Over two hundred radioactive isotopes are manufactured for use in medicine and industry. Radioisotopes can be used to analyze materials, trace flows and treat commodities. Here is a list of commonly used radioisotopes.
Americium-241 has a half-life of 432 years. It is used in backscatter gauges, smoke detectors, in measuring ash content of coal, in measuring toxic lead in dried paint, in measuring thickness in rolling processes for paper and steel.
