Symptoms of Radiation Exposure

Psychiatric symptoms occur through several mechanisms (see Table 3—2). The review of therapeutic uses of radiation, atom bomb expo- 

TABLE 3-1. Signs and symptoms of ionizing radiation exposure 

Acute (hours to days) Nausea, diarrhea, anorexia, vomiting, 

Delayed (days to months) Abdominal pain, fever, dehydration from 

Delayed (months to years) Pulmonary fibrosis, cor pulmonale, 

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Because radiation exposure can be cumulative, there are no truly safe levels of exposure to radioactive materials. Radiation does not cause any specific diseases. Symptoms of radiation exposure may be the same as those from exposure to cancer-causing materials. The tolerable limits for exposure to radiation that have been proposed by some scientists are arbitrary. Scientists concur that some radiation damage can be repaired by the human body. Therefore, tolerable limits are considered acceptable risks when the activity benefits outweigh the potential risks. The maximum annual radiation exposure for an individual person in the United States is 0.1 REM. Workers in the nuclear industry have a maximum exposure of 5 REMs per year. An emergency exposure of 25 REMs has been established by The National Institute of Standards and Technology for response personnel. This type of exposure should be attempted under only the most dire circumstances and should occur only once in a lifetime. 

Plans should therefore call for promptly making public announcements if a moderate- or high-hazard device (see Table 9.2) is lost or stolen. In addition, these plans should call for informing hospitals of the symptoms of radiation exposure so that affected people can be identified and the source can be found. 

Persons with symptoms of radiation exposure Patients should be transported urgently to a specialized hospital after appropriate medical care. Experience has shown that localized external exposure, often without radioactive contamination, is the most common consequence of radiological accident. In most cases, the treatment can be offered in hospital units specifically identified for this purpose as part of a medical emergency plan. Persons with combined injuries radiation plus conventional trauma) Treatment of such patients has to be individualized in accordance with the nature and grade of the combined injury. Usually, a combination of radiation exposure with mechanical, thermal, or chemical injuries may worsen prognosis. 

In terms of health effects, none of the evacuees from the 30 km radius evacuation zone displayed any symptoms of radiation sickness. Their collective dose from external exposure wa.s estimated to be 1.5... 

Specific health effects resulting from an acute dose appear only after the victim exceeds a dose threshold. That is, the health effect will not occur if doses are below the threshold. (Note that this is significantly different from the LNT model used to predict stochastic effects.) After reaching the acute dose threshold, a receptor can experience symptoms of radiation sickness, also called acute radiation syndrome. As shown in Table 3.2, the severity of the symptoms increases with dose, ranging from mild nausea starting around 25-35 rad (0.25-0.35 Gy) to death at doses that reach 300-400 rad (3-4 Gy). Table 3.2 shows that the range of health effects varies by both total dose and time after exposure. 

Patients exposed to moderateiy high ieveis of radiation (100 rad or less) will likely exhibit no symptoms of radiation sickness while at the scene. Laboratory work will show a depression in red and white blood cells, but this may not appear for several days after the exposure. About 10% of patients exposed to 100 rad will exhibit mild radiation sickness, but may not attribute it to radiation exposure. 

In following months and years, more nearby residents became concerned that any health problems, including cancer, miscarriages, anxiety-related symptoms, and birth defects were the result of radiation exposure from the TMI accident. In all cases, it was determined that insufficient radioactivity had escaped and the accident was not the cause of these symptoms. Even after more than 2 decades, however, this remains a contentious issue. 

Have or do workers exhibit any signs and symptoms of radiation sickness or exposures ... 

Neurotoxicity is the result of improper (careless) use, handling, and negligence in the management of chemical substances such as metals, food additives, pesticides, industrial solvents, cosmetics, radiation treatment, and drug therapies. Depending upon route and dose of exposure, the symptoms of neurotoxicity appear immediately after exposure or are delayed. The symptoms include limb weakness or numbness loss of memory, vision, and/or intellect headache cognitive and behavioral problems and sexual dysfunction. Children and workers with certain existing health disorders are more vulnerable to the adverse effects of neurotoxic chemicals. 

Mental retardation and microcephaly Acute stress symptoms, posttraumatic stress symptoms Personality disorders A-bomb neurosis or radiation response syndrome excessive anxiety over symptoms of exposure, fear of cancer, subclinical stress symptoms... 

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