Sickness, radiation

Dimenhydrinate is an antiemetic especially usehil as an antinauseant in motion sickness, and for syndromes associated with vertigo such as Meniere s syndrome, radiation sickness, and vestibular dysfunction. It may produce mild drowsiness. It is FDA Category B for Pregnancy, and is available as an OTC preparation as well as by prescription. 

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... 

Someone is exposed to a source of p radiation that results in a dose rate of 1.0 rad-d. Given that nausea begins after a dose equivalent of about 100 rem, after what period will that symptom of radiation sickness be apparent ... 

The nuclear explosions that devastated Hiroshima and Nagasaki killed 100,000 to 200,000 people instantaneously. Probably an equal number died later, victims of the radiation released in those explosions. Millions of people were exposed to the radioactivity released by the accident at the Chernobyl nuclear power plant. The full health effects of that accident may never be known, but 31 people died of radiation sickness within a few weeks of the accident, and more than 2000 people have developed thyroid cancer through exposure to radioactive iodine released in the accident. Even low levels of radiation can cause health problems. For this reason, workers in facilities that use radioisotopes monitor their exposure to radiation continually, and they must be rotated to other duties if their total exposure exceeds prescribed levels. 

Different t T)es of body cells show different sensitivities to nuclear radiation. Cells that divide most rapidly tend to be most easily damaged. These include bone marrow, white blood cells, blood platelets, the lining of the gastrointestinal tract, and cells in the gonads. Consequently, the S3Tnptoms of radiation sickness include loss of blood functions and gastrointestinal distress. 

Latent period Period of seeming inactivity between time of exposure of tissue to an acute radiation dose and the onset of the final stage of radiation sickness. 

The Little Boy bomb initially killed approximately 70,000 people and injured another 70,000. By the end of 1945, the death toll rose to 140,000 due to radiation sickness. Five years later, the death toll was 200,000. The initial death rate from Fat Man was 40,000 with 60,000 injured the death rate eventually rose to about 140,000. 

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. 

The radioactive isotope calcium-45 is deposited in bones and teeth as well as other plant and animal tissues. Because our bodies cannot distinguish between Ca-45 and the stable Ca-40, the radioactive isotope Ca-45 is used as a tracer to study diseased bone and tissue. At the same time, a massive overexposure to Ca-45 can displace the stable form of Ca-40 in animals and can cause radiation sickness or even death. 

Because radium energetically emits three types of radiation, it poses great danger to anyone handling it. In addition, it is toxic. If it is ingested in even small amounts, it replaces bone tissue, which can result in radiation sickness and death. 

The Curies were both exposed to radiation and were the first persons to suffer from radiation sickness, resulting in an early death for Marie. Pierre was killed in an accident with a horse and carriage. Marie s notebooks are still radioactive. 

The problem is that nuclear wastes contain radioactive isotopes that release life-threatening ionizing radiation that may pose a threat to humans and the environment for hundreds, thousands, or even millions of years. This radiation can cause carcinogenic, teratogenic, and mutagenic effects in small amounts and can result in radiation sickness and death in larger amounts. 

In 1986, a meltdown occurred at this nuclear power plant in Chernobyl, Ukraine. Because there was no containment building, large amounts of radioactive material were released into the environment. Three people died outright, and dozens more died from radiation sickness within a few weeks. Thousands who were exposed to high levels of radiation stand an increased risk of cancer. Today, 10,000 square kilometers of land remain contaminated with high levels of radiation. 

Therapeutic Procedures Therapeutic procedures—those in which radiation is used to kill diseased tissue—can involve either external or internal sources of radiation. External radiation therapy for the treatment of cancer is often carried out with y rays from a cobalt-60 source. The highly radioactive source is shielded by a thick lead container and has a small opening directed toward the site of the tumor. By focusing the radiation beam on the tumor and rotating the patient s body, the tumor receives the full exposure while the exposure of surrounding parts of the body is minimized. Nevertheless, sufficient exposure occurs so that most patients suffer some effects of radiation sickness. 

The simplest silatranes, XSifOCH CHj N where X = H, C6H5, C1CH2 as well as l-(chloromethyl)-3,7,10-trimethylsilatrane display no radio-protective effect on mice suffering from radiation sickness induced by 1000 r irradiation. 

N. N. Suvorov and V. S. Shashkov, Chemistry and Pharmacology of Agents for Treatment of Radiation Sickness [in Russian], Atomizdat, Moscow (1975), p. 39. 

Commonly used radiopharmaceuticals are carbon 14 (ti/2 30 years), cobalt 57 (ti/2 271 days), cobalt-58 (ti/2 70.8 days), gold-198 (ti/2 2.7 days), iodine-123 (ti/2 12.3 hours), iodine-125 O1/2 60 hours), iodine-131 (ti/2 8.04 days), and tritium (ti/2 12.3 years). The iodine radioisotope is used to study thyroid function and is used in the treatment of hyperthyroidism and thyroid carcinoma. Various monoclonal antibodies labeled with iodine-171 are used for the detection of malignant neoplasms. Genetic damage is a dangerous side effect of radioactive isotopes prior to and during the reproductive period. Exposure to large doses leads to leukopenia, anemia, skin inflammation, radiation sickness, and neoplasm. 

The 1,3-dioxolane ring is found in a major antifungal drug, ketoconazole (123). Ketoconazole is a broad spectrum, orally active antifungal agent and is used to treat a wide variety of superficial or deep fungal infections. Various workers, especially in Russia, have explored the use of simple oxathiolanes as radioprotectants. For example, the survival rate of mice irradiated with lethal doses of X- or -y-rays was 40% when they were pretreated with 2,2-dimethyl-l,3-oxathiolane. Other oxathiolanes were less active. 1,3-Oxathiolane, administered intravenously to dogs 2 or 3 times daily for 2-4 days before chronic irradiation with polonium-210, increased their life expectancy from 9 months to 3-7 years and alleviated radiation sickness. Some blood indicators were also restored to normal. 

The use of radiation dispersal devices, commonly referred to as dirty bombs, is particularly concerning for disaster planning and emergency preparedness personnel. An RDD is an explosive device designed to spread radioactive material without a nuclear explosion (Briggs Brinsfield, 2003). The initial blast from the explosion can kill or inflict mechanical trauma on those who are close in proximity to the explosion while the radioactive material is dispersed. Please refer to chapter 27, Radiological Incidents and Emergencies, for further information on decontamination, radiation sickness, and personal protective measures. 

A radiological incident may be as dramatic as a terrorist attack or as mundane as mild skin contamination from a minor spill. Radiological incidents have resulted in death from radiation sickness, but the vast majority of cases simply require decontamination and monitoring. 

Acute radiation exposure, which can cause radiation sickness, radiation burns, and so forth, is caused by the energy deposited in the body, and so we are looking for effects that will occur within hours, days, or weeks of the exposure. As cancer takes many years or decades to develop, quantifying the long-term effects of DNA damage resulting from an acute exposure is not as important. In the case of acute radiation exposure, then, we measure only the amount of energy deposited in the body, so we use units of Gy or rad. 

In this chapter, we will follow this convention of using units of Gy and rad when we are concerned about the short-term risk of skin burns, radiation sickness, or fatal radiation injury that results from acute radiation exposure and using units of Sv and rem when we discuss the risk of developing cancer many years or decades after the radiation exposure, or when we are discussing compliance with radiation safety regulations. 

Radiation sickness Mild at lower doses, severity and rapidity of onset increases rapidly with increasing dose. 

Hematopoietic syndrome Changes in blood cell count from damage to crypt cells, severe radiation sickness, recovery possible with medical support. 

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. 

Patients exposed to higher levels of radiation will experience more severe radiation sickness that will appear more rapidly. A patient receiving a dose of about 400 rad has a 50% chance of death without medical intervention, primarily from radiation-induced immune system suppression and subsequent infectious disease. 

With medical support, such patients are likely to survive exposure. These patients will also experience radiation sickness. If radiation sickness appears within 30 to 60 minutes after exposure, however, the patient has likely received a fatal dose of radiation. Such patients should be made as comfortable as possible. 

No observed effects Chromosome damage White cell depression Radiation sickness begins... 

Patients exhibiting signs of radiation sickness immediately after an accident have likely received a fatal dose of radiation. Tfeating their symptoms will help to make them comfortable until a physician specializing in such cases can be contacted for the most recent medical advice. Such advice is available from the REAC/TS center at the Oak Ridge National Laboratory (http //orise.orau.gov/reacts/). 

Japan lr-192 5.26 Ci Industrial source 15-130 rad 3 cases of radiation sickness among 6 exposed... 

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