Radiation damage to tissues
Radiation damage to tissues refers to the injury inflicted on the human body by energy waves, particularly those that emit ions as they pass through. This type of damage can result from both ionizing and nonionizing radiation, with ionizing radiation being more harmful due to its ability to emit charged particles that disrupt cellular function. While nonionizing radiation, such as sunlight, is generally less dangerous, ionizing radiation includes alpha particles, beta particles, gamma rays, and X-rays, each causing different patterns of tissue damage.
Damage from radiation can range from immediate effects, such as skin burns and Acute Radiation Syndrome, to long-term consequences like cancer and genetic mutations. Cells that divide rapidly, such as those in the skin and bone marrow, are particularly vulnerable to radiation exposure. Symptoms of radiation damage can include vomiting, hair loss, and changes in blood cell counts, with severe exposure potentially leading to fatal outcomes. The assessment of radiation exposure and its effects is often conducted through dosimetry, which calculates the amount absorbed by the tissues.
Additionally, exposure during pregnancy poses risks to fetal development, increasing the likelihood of mental health issues and childhood cancers. Understanding the implications of radiation exposure is crucial for both medical treatment and forensic investigations, as it helps in identifying the type and extent of damage sustained.
Subject Terms
Radiation damage to tissues
DEFINITION: Injury caused to the human body by energy waves as they pass through the body emitting ions.
SIGNIFICANCE: Radiation damage may be a cause of death or injury that is not immediately obvious. By examining the pattern of damage in a body, a forensic pathologist can determine whether radiation caused the damage and, if so, what type of radiation was involved.
Radiation is everywhere, including in sunlight, and can pass through the body harmlessly. Certain types of radiation, however, can cause massive internal or external damage leading to death. Depending on the level or concentration of radiation, it may cause damage internally without noticeable external damage.
Types of Radiation
Radiation is either ionizing (ions are emitted into body tissues as the radiation passes through) or nonionizing. Nonionizing radiation is considered to be less dangerous because it passes through tissues without emitting any energy; sunlight is an example of this type of radiation. Types of ionizing radiation, which cause tissue damage as they emit ions into the tissues they penetrate, include alpha particle radiation, beta particle radiation, gamma rays, and X rays.
Different types of radiation damage body tissues in different patterns. For example, alpha particle radiation (often called alpha rays) causes an intense, local concentration of energy. Gamma radiation penetrates more deeply into the tissues, causing a more even and wide distribution of damage. By examining such damage patterns, a forensic pathologist can gain information about what type of radiation was involved in the radiation exposure.
Tissue Damage from Radiation
Radiation damages body tissues when ions are emitted into tissues. These ions are charged atomic particles, and they take electrons from atoms and molecules in the tissues, making those atoms and molecules unable to function. Radiation is most damaging to tissues when a concentrated amount of radiation destroys molecules in a small, defined area. This is why radiation can be used beneficially, for example, in destroying cancerous cells.
High levels or concentrations of radiation can cause massive burning of the skin and trigger death nearly immediately. However, low levels of radiation can be damaging as well. They may cause cell mutations or increase the likelihood that already mutated cells will reproduce at faster speeds. They may also cause internal damage that is not immediately obvious. The calculation of the amount of radiation absorbed by tissues is known as dosimetry.
Alpha rays generally do not penetrate below the first layer of dead skin cells and, as such, do not generally cause much tissue damage. Beta rays penetrate slightly deeper and cause damage such as surface burns to the skin (much like sunburn, but these burns take longer to heal). Although it is possible for beta rays to penetrate more deeply into the body, it is generally unlikely that these rays could cause much damage to internal organs. Gamma rays have the ability to penetrate deeply into the body and are much more likely to cause damage to internal organs than are the other types of ionizing radiation.
All cells in the body are not affected by radiation in the same way. Cells that divide rapidly or are more nonspecialized (relatively speaking) are affected at lower doses or concentrations of radiation than are cells that divide less rapidly or are more specialized. When radiation enters cells in the body, the cells can be affected in four different ways: They can remain undamaged and continue to function normally; they can become damaged, repair the damage, and continue to function normally; they can become damaged and repair the damage but be unable to continue functioning normally; or they can die and cease to function altogether.
Radiation damage is first noticeable in those cells that affect the body’s rapidly changing tissues—cells in the intestines, skin, bone marrow, and reproductive organs, particularly the testicles. Damage to these tissues results in symptoms such as vomiting, burns, hair loss, changes in white blood cell count, and sterility. Long-term effects include eye cataracts, cancers, and genetic mutations.
Acute Radiation Syndrome
An acute radiation dose (a large dose delivered to the whole body in a short period of time, such as in a radiation bomb blast or an accidental industrial exposure) can cause a pattern of damage referred to as acute radiation syndrome. This syndrome is characterized by damage to bone marrow, spleen, and lymph tissue, causing symptoms such as fatigue, fever, infections, and internal bleeding. The central nervous system is also affected, with damage to nerve cells causing symptoms such as confusion, coma, convulsions, loss of coordination, and shock. In addition, damage to the lining of the stomach and intestines causes symptoms such as bleeding ulcers, dehydration, diarrhea, digestive problems, electrolyte imbalance, nausea, and vomiting. An acute dose can also cause lasting damage to the thyroid gland, ovaries, and testicles.
Exposure to radiation can also have an effect on an embryo or fetus because as the fetus grows, its tissue cells are growing and dividing rapidly. If a pregnant woman is exposed to radiation, her child may have increased risks of mental problems or childhood cancers.
Bibliography
Ahmed, Syed Naeem. Physics and Engineering of Radiation Detection. San Diego: Academic Press, 2007.
Byrnes, Mark E., David A. King, and Philip M. Tierno, Jr. Nuclear, Chemical, and Biological Terrorism: Emergency Response and Public Protection. Boca Raton, Fla.: CRC Press, 2003.
Holmes-Siedle, Andrew, and Len Adams. Handbook of Radiation Effects. 2d ed. New York: Oxford University Press, 2002.
Iddins, Carol J., et al. "Cutaneous and Local Radiation Injuries." Journal of Radiological Protection, vol. 42, no. 1, 2022, doi: 10.1088/1361-6498/ac241a. Accessed 16 Aug. 2024.
Knoll, Glenn F. Radiation Detection and Measurement. 3d ed. New York: John Wiley & Sons, 2000.
National Council on Radiation Protection and Measurements. Management of Terrorist Events Involving Radioactive Material. Bethesda, Md.: Author, 2001.
Stabin, Michael G. Radiation Protection and Dosimetry: An Introduction to Health Physics. New York: Springer, 2007.