Radiation Injuries Health Article

Ultraviolet (UV) radiation exposure from the sun and tanning beds

UV radiation from the sun and tanning beds and lamps can cause skin damage, premature aging, and skin cancers. Malignant melanoma is the most dangerous of skin cancers and there is a definite link between type UVA exposure used in tanning beds and its occurrence. UVB type UV radiation is associated with sunburn, and while not as penetrating as UVA, it still damages the skin with over exposure. Skin damage accumulates over time, and effects do not often manifest until individuals reach middle age. Light-skinned people who most often burn rather than tan are at a greater risk of skin damage than darkerskinned individuals that almost never burn. The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control (CDC) discourage the use of tanning beds and sun lamps and encourage the use of sunscreen with at least an SPF of 15 or greater. In addition, the rising incidence of melanoma in the United States has led the Environmental Protection Agency (EPA) to develop a sun safety education program for school-age children in order to begin changing public attitudes toward tanning.

Overexposure during medical procedures

Ionizing radiation has many uses in medicine, both in diagnosis and in treatment. X rays, CT scanners, and fluoroscopes use it to form images of the body's insides. Nuclear medicine uses radioactive isotopes to diagnose and to treat medical conditions. In the body, radioactive elements localize to specific tissues and give off tiny amounts of radiation. Detecting that radiation provides information on both anatomy and function. During the past 10 years, skin injuries caused by too much exposure during a medical procedure have been documented. In 1995, the FDA issued a recommendation to physicians and medical institutions to record and monitor the dosage of radiation used during medical procedures on patients in order to minimize the amount of skin injuries. The FDA suggested doses of radiation not exceed 1 Grey (Gy). (A Grey is roughly equivalent to a sievert.) As of 2001, the FDA was preparing further guidelines for fluoroscopy, the procedure most often associated with medical-related radiation skin injuries such as rashes and more serious burns and tissue death. Injuries occurred most often during angioplasty procedures using fluoroscopy.

CT scans of children have also been problematic. Oftentimes the dosage of radiation used for an adult isn't decreased for a child, leading to radiation overexposure. Children are more sensitive to radiation; a February 2001 study indicates 1,500 out of 1.6 million children under 15 years of age receiving CT scans annually will develop cancer. Studies show that decreasing the radiation by half for CT scans of children will effectively decrease the possibility of overexposure while still providing an effective diagnostic image. The benefits to receiving the medical treatment utilizing radiation is still greater than the risks involved; however, more stringent control over the amount of radiation used during the procedures will go far to minimize the risk of radiation injury to the patient.

Recent evidence suggests that some ethnic groups may be more vulnerable than others to radiation damage. A study done at New York University found that Jews are more likely to develop ovarian cancer as a delayed side effect of diagnostic x-rays of the abdomen than non-Jews. These findings require confirmation by further research, but they do indicate that ethnicity and other genetic factors are involved in susceptibility to radiation damage.

Side effects from radiation therapy to treat cancer

As many as half of all cancer patients receive some form of radiation therapy as a component of treatment.

The therapy can be delivered from either an external or an internal source, although the former is more common. The machines used for external radiation have become more specialized to deliver the appropriate dose to either a superficial or a deep location on the body. Depending on the type and site of cancer being treated, internal sources of radiation can be injected, swallowed, or placed within the body in sealed containers. These are implanted into or near the tumor, either temporarily or permanently.

Some types of tumors may be eliminated by radiation therapy, if the patient is able to withstand the necessary dose. In other cases, radiation is used in conjunction with other methods of treatment. It may be given before surgery, to shrink a tumor to an operable size, or after surgery, to try to destroy any cancerous cells that may remain. Radiation can be used to make patients with incurable disease more comfortable by decreasing the bulk of tumors to reduce pain or pressure. Treatment that is given as a comfort measure only is known as palliation, or palliative therapy.