X-rays and gamma rays can cause a number of other problems besides cancer. What problems occur depend upon the radiation dose, the timing of the exposure, and what areas of the body are exposed.
Exposure to high doses of radiation over a short period of time can cause radiation sickness sometimes called radiation poisoning or acute radiation syndrome and even death. Some of the symptoms of radiation sickness include fainting, confusion, nausea and vomiting, diarrhea, hair loss, skin and mouth sores, and bleeding.
The atomic bomb blasts in Hiroshima and Nagasaki led to many cases of radiation sickness. Since then, some cases have resulted from nuclear power plant accidents, such as those in Chernobyl and in Fukushima. Doses of radiation such as those given in radiation therapy also cause side effects. Short-term side effects depend on the area being treated but often include skin changes ranging from mild reddening to something like a severe burn , nausea, vomiting, diarrhea, and low blood cell counts.
There is also a risk of long-term side effects, which again vary depending on the area being treated. For example, radiation to the head and neck area can lead to problems with dry mouth and trouble swallowing. In the case of Fukushima evacuation up to 20km from the power plants was much faster. Much higher doses up to mSv were received by some clean-up workers after Chernobyl, and little is known yet about doses to clean-up workers at Fukushima. If recent reports of doses up to 2.
To cause death within hours of exposure to radiation, the dose needs to be very high, 10Gy or higher, while Gy will kill within 60 days, and less than 1. However all doses, no matter how small, carry a finite risk of cancer and other diseases. This cancer risk may persist for the remainder of life but is unlikely to appear before at least years after exposure. On this basis some 30, to 60, cancer deaths worldwide, but mainly in Europe, will have been caused by the Chernobyl accident, and many still remain to occur.
Much discussion is made of the so-called low dose problem. Effects from doses of less than 50mSv are difficult to assess directly due to the high background of spontaneous naturally occurring cancer, so it has been necessary to extrapolate down from measurements of effects at higher doses.
The question is whether there is a dose threshold below which there is no effect. From what we know that threshold must be below 10mSv and by the age of ten everybody has received at least 10mSv natural background radiation from natural background sources, so there is no argument for a threshold — all doses of radiation, no matter how small, entail a finite risk. Portsmouth Climate Festival — Portsmouth, Portsmouth. Edition: Available editions United Kingdom. Become an author Sign up as a reader Sign in.
Keith Baverstock , University of Eastern Finland. We use this property of radiation to kill cancer cells, and also harmful bacteria and other micro-organisms. The hazard symbol is shown on containers of radioactive substances to warn of the danger. The degree to which each different type of radiation is most dangerous to the body depends on whether the source is outside or inside the body.
If the radioactive source is inside the body , perhaps after being swallowed or breathed in:. If the radioactive source is outside the body:.
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