Non-radioactive iodine

About lO becquerels of iodine-131 were released in the accident. Iodine is mainly absorbed by a person s thyroid gland after inhalation or after consumption of contaminated foodstuffs such as milk products its short-range beta particles irradiate the gland from the inside. Uptake of iodine by the thyroid is very easy to prevent, for example by banning consumption of contaminated food for a few weeks until the iodine-131 decays sufficiently or by administering small amounts of non-radioactive iodine prophylactic-ally to block the thyroid gland. 

Some radioactive nuclides are especially damaging because they tend to concentrate in particular parts of the body. For example, because both strontium and calcium are alkaline earth metals in group 2 on the periodic table, they combine with other elements in similar ways. Therefore, if radioactive strontium-90 is ingested, it concentrates in the bones in substances that would normally contain calcium. This can lead to bone cancer or leukemia. For similar reasons, radioactive cesium-137 can enter the cells of the body in place of its fellow alkali metal potassium, leading to tissue damage. Non-radioactive iodine and radioactive iodine-131 are both absorbed by thyroid glands. Because iodine-131 is one of the radioactive nuclides produced in nuclear power plants, the... 

Chernobyl accident released large quantities of it. To reduce the likelihood of thyroid damage, people were directed to take large quantities of salt containing non-radioactive iodine-127. This flooding of the thyroid glands with the non-damaging form of iodine made it less likely that the iodine-131 would be absorbed. 

Iodine adsorbed onto the Pt surface is believed to be in the atomic state, and can be easily exchanged with non-radioactive iodine, I2 or I, in solution. This isotopic exchange procedure is very convenient for preparing labeled compounds, as discussed in Radiation chemistry of iodine in aqueous solutions . 

The thyroid cannot tell the difference between radioactive and non-radioactive iodine. It will take up radioactive iodine in whatever proportion it is available in the environment. 

The principal isotopes of concern from the accident were iodine-131 and cesium-137. Iodine-131 is of concern because it concentrates in the thyroid gland and can lead to thyroid cancer, although this is treatable with survivability of about 95 per cent. Iodine-131 has a short half-life of about 8 days, so after two months it has effectively disappeared. Thyroid cancers may then develop within a few years of the exposure. In Piipyat and some other areas, people were given potassium iodate tablets to swamp their thyroids with non-radioactive iodine, thereby preventing uptake of iodine-131. 

Humphrey and Keller (1970) found that the synthetic antigen TGAL, extensively iodinated to very high specific activity (1400 [xCi (jig ) was unable to elicit an antibody response in mice, whereas TGAL substituted with non-radioactive iodine could do so. 

This hot antibody is linked to radioactive iodine and binds to the CD20 receptor present on B lymphocytes (see Rituximab above). Tositumomab has shown activity in non-Hodgkin s lymphoma. Hematologic toxicity occurs several weeks after administration and may persist for months. Since radioactive iodine may have adverse effects on the thyroid, all patients must receive thyroid-blocking agents. 

Radioactive/Non-radioactive Detection Systems. Radioisotopic detection methods frequently employ molecules containing radionuclides of hydrogen, sulfur and phosphorus, and less frequently iodine and chromium. Oftentimes, the probe molecules themselves are directly radiolabeled for immediate detection. 

Tositumomab Murine anti-CD20 antibody Bexxar Antineoplastic. Murine IgG2 anti-CD20 mAb. Produced in cultured mammalian cells. Can be covalently hnked to radioactive Iodine 131. non-Hodgkin s lymphoma... 

Most industrial filters eliminate radioactive iodine (primarily but also and I) and bromine by ion exchange with non-radioactive I or Br. Usually the activated carbon has been impregnated with potassium iodide (KI, see Table 1), Another possibility is an impregnation with triethylenediamine (TEDA) [40,86-88]. There are several possible reaction schemes, but tlie most probable one is the formation of a quaternary ammonium salt (Eq.35) [88]. 

Operation of the main control room habitability system is automatically initiated on high-2 particulate or iodine radioactivity set point, or low pressuriser pressure, a safety related signal is generated to isolate the main control room from the nuclear island non-radioactive ventilation system and to initiate air flow from the main control room habitability system storage tanks. Isolation of the nuclear island non-radioactive ventilation system consists of closing valves in the supply and exhaust ducts that penetrate the main control room pressure boundary. Main control room habitability system airflow is initiated by a signal which opens the isolation valves in the main control room habitability system supply lines (see Section 6.4 of Reference 6.1). 

Finally, the small amine-reactive and photoreactive crosslinker, NHS-ASA (Chapter 5, Section 3.1), can be iodinated to provide a non-cleavable radioactive conjugate. 

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