Radiation Injuries Health Article

Causes and symptoms

Radiation can damage every tissue in the body. The particular manifestation will depend upon the amount of radiation, the time over which it is absorbed, and the susceptibility of the tissue. The fastest growing tissues are the most vulnerable, because radiation as much as triples its effects during the growth phase. Bone marrow cells that make blood are the fastest growing cells in the body. A fetus in the womb is equally sensitive. The germinal cells in the testes and ovaries are only slightly less sensitive. Both can be rendered useless with very small doses of radiation. More resistant are the lining cells of the body—skin and intestines. Most resistant are the brain cells, because they grow the slowest.

The relative sensitivity of various tissues gives a good idea of the wide range that presents itself. The numbers represent the minimum damaging doses; a gray and a sievert represent roughly the same amount of radiation:

• fetus—2 grays (Gy)
• bone marrow—2 Gy
• ovary—2–3 Gy
• testes—5–15 Gy
• lens of the eye—5 Gy
• child cartilage—10 Gy
• adult cartilage—60 Gy
• child bone—20 Gy
• adult bone—60 Gy
• kidney—23 Gy
• child muscle—20-30 Gy
• adult muscle—100+ Gy
• intestines—45–55 Gy
• brain—50 Gy

Notice that the least of these doses is a thousand times greater than the background exposure and nearly 50 times greater than the maximum permissible annual dosage.

The length of exposure makes a big difference in what happens. Over time the accumulating damage, if not enough to kill cells outright, distorts their growth and causes scarring and/or cancers. In addition to leukemias, cancers of the thyroid, brain, bone, breast, skin, stomach, and lung all arise after radiation. Damage depends, too, on the ability of the tissue to repair itself. Some tissues and some types of damage produce much greater consequences than others.

Immediately after sudden irradiation, the fate of the patient depends mostly on the total dose absorbed. This information comes mostly from survivors of the atomic bomb blasts over Japan in 1945.

• Massive doses incinerate immediately and are not distinguishable from the heat of the source.
• A sudden whole body dose over 50 Sv produces such profound neurological, heart, and circulatory damage that patients die within the first two days.
• Doses in the 10–20 Sv range affect the intestines, stripping their lining and leading to death within three months from vomiting, diarrhea, starvation, and infection.
• Victims receiving 6–10 Sv all at once usually escape an intestinal death, facing instead bone marrow failure and death within two months from loss of blood coagulation factors and the protection against infection provided by white blood cells.
• Between 2–6 Sv gives a fighting chance for survival if victims are supported with blood transfusions and antibiotics.
• One or two Sv produces a brief, non-lethal sickness with vomiting, loss of appetite, and generalized discomfort.

Treatment

It is clearly important to have some idea of the dose received as early as possible, so that attention can be directed to those victims in the 2–10 Sv range that might survive with treatment. Blood transfusions, protection from infection in damaged organs, and possibly the use of newer stimulants to blood formation can save many victims in this category.

Local radiation exposures usually damage the skin and require careful wound care, removal of dead tissue, and skin grafting if the area is large. Again infection control is imperative.

Alternative treatment

There is considerable interest these days in benevolent chemicals called "free radical scavengers." How well they work is yet to be determined, but population studies strongly suggest that certain diets are better than others, and that those diets are full of free radical scavengers, otherwise known as antioxidants. The recommended ingredients are beta-carotene, vitamins E and C, and selenium, all available as commercial preparations. Beta-carotene is yellow-orange and is present in yellow and orange fruits and vegetables. Vitamin C can be found naturally in citrus fruits. Traditional Chinese medicine (TCM) and acupuncture, botanical medicine, and homeopathy all have contributions to make to recovery from the damage of radiation injuries. The level of recovery will depend on the exposure. Consulting practitioners trained in these modalities will result in the greatest benefit.

BOOKS

Harrison's Principles of Internal Medicine. Ed. Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.

Upton, Arthur C. "Radiation Injury." In Cecil Textbook of Medicine, ed. J. Claude Bennett and Fred Plum. Philadelphia:W. B. Saunders Co., 1996.

Weil, Andrew. Natural Health, Natural Medicine. Boston: Houghton Mifflin, 1995.

J. Ricker Polsdorfer, MD