Gamma radiation is a form of nuclear radiation produced by certain radioactive elements as they decay. In particular, gamma radiation is ionizing radiation, meaning that it is sufficiently energetic to break bonds in genetic material, structural components of cells and other biological molecules. For this reason, exposure to gamma radiation can cause a number of health effects, some of which accumulate over time, and others of which are acute. While the body has the ability to repair damage, its ability to repair radiation-related damage can be overwhelmed at high doses or if radiation accumulates over many years.
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Mild Radiation Sickness
If an individual is exposed to small doses of gamma radiation, or very small doses of gamma radiation regularly for some time, they may develop a mild case of radiation poisoning. While radiation can kill any body cell, the most susceptible cells are the fastest-growing ones, since their genetic material is most exposed. As a result, the skin, hair and gastrointestinal tract cells are most likely to be affected first in radiation exposures. According to the Mayo Clinic, symptoms of mild radiation poisoning include nausea and vomiting, progressing to generalized weakness and fatigue several weeks later.
Severe Radiation Sickness
Larger acute doses of gamma radiation, or larger doses that accumulate over time, can lead to much more severe symptoms. These may include diarrhea, headache, hair loss, skin burns and poor healing, according to the Mayo Clinic. A 2007 study published in “Health Physiology” also reports that severe radiation sickness can result in death, either immediately or within months. The study notes that delayed radiation deaths were generally attributable to bone marrow failure. Since the bone marrow, like skin, contains rapidly dividing cells, it’s quite vulnerable to radiation. The marrow is responsible for producing both red and white blood cells—the red cells carry oxygen to the tissues, and the white cells are part of the immune system. Failure of the bone marrow to proliferate blood cells properly is fatal.
Individuals who are exposed to gamma radiation, even if they recover from the acute and chronic effects of radiation sickness, are at increased risk for cancer, notes the Environmental Protection Agency, or EPA. While body cells that divide slowly are not nearly as susceptible to radiation as those that divide more rapidly, their genetic material can still be damaged by radiation. As such, when the cells do divide, the daughter cells may contain damaged copies of genetic material, which is then passed on to the next generation of cells, and so forth. Over time, the proliferation of faulty genetic material can create an aberrant cell mass that does not function like normal tissue, and may divide rapidly. This represents a neoplasm, or new growth, which may be cancerous and spread throughout the body.
- The Mayo Clinic: Radiation Sickness
- "Health Physiology"; Health effects in those with acute radiation sickness from the Chernobyl accident; F. Mettler, et al; November 2007
- Environmental Protection Agency: Radiation Exposure