X-rays are a kind of radiation, or electromagnetic wave. They’re very closely related to phenomena such as radio waves and waves of visible light, but unlike either of these, X-rays are capable of breaking bonds in biological molecules. This ability to destroy molecules denotes X-rays as a type of ionizing radiation, a category to which gamma radiation also belongs. Like gamma radiation, X-ray radiation effects can cause damage to living cells, tissues and organs. Damage can result from single high doses or can build up over time if many smaller exposures occur within a short period.
DNA Damage
DNA is genetic material. It’s a very long, delicate molecule that’s normally kept coiled up and protected in the nucleus of a cell. Dividing cells, however, uncoils DNA so that it can be replicated, and a copy passed to the new cell. Biochemists Mary Campbell, Ph.D. and Shawn Farrell, PhD. note that dividing cells are at much greater risk for damage from ionizing radiation such as X-rays than are cells that have their DNA protected. As such, rapidly-dividing cells, including skin cells, hair follicles and the lining of the digestive tract, are at greatest risk for damage.
Aging
Genetic material is not the only type of molecule at risk for breakage by X-rays. Proteins and structural tissues can become damaged as well. In particular, the collagen proteins that help skin maintain its elasticity are susceptible to damage; when collagen molecules break, they lose their ability to act as elastic skin supports. The U.S. Nuclear Regulatory Committee publishes a manual called “Biological Effects of Radiation” in which they note that aging effects of skin, organs and other tissues can result from X-ray exposure.
Cancer
Radiation exposure, even before birth, leads to increased risk for cancer, notes the U.S. Centers for Disease Control and Prevention, or CDC. When genetic material within a cell becomes damaged, the damage often causes the cell to lose restrictions on its ability to grow and divide. As a result, damaged cells divide and grow rapidly, forming tumors that can steal nutrition from healthy body cells. This damages the organs in which the tumors are located, and can lead to organ failure and death. All cells are susceptible to genetic damage from X-rays, but the ones most likely to be affected are cells that are actively dividing when radiation exposure occurs.
Death
Jefferson Lab notes that exposure to large doses of radiation can overwhelm the body’s ability to heal damage. As such, very large single doses of X-rays or X-ray accumulation over time can lead to radiation sickness, including symptoms such as vomiting, disorientation and mental deficiencies. Depending upon the strength of the dose, radiation sickness can kill within minutes or up to several months after exposure.
References
- “Biochemistry”; Mary Campbell, Ph.D. and Shawn Farrell, Ph.D.; 2005
- "Reactor Concepts Manual"; Biological Effects of Radiation; U.S. Nuclear Regulatory Committee
- Jefferson Labs: X-ray Effects
- U.S. Centers for Disease Control and Prevention: X-ray Effects
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