Why is the half-life of Iodine 131 important?
Iodine 131 is a radioisotope with a very short half-life of 8.02 days, making it highly radioactive. Frequently used in small doses in thyroid cancers therapies, it is also one of the most feared fission products when accidentally released into the environment.
What are the main uses of iodine 131?
I-131 is used in medicine to diagnose and treat cancers of the thyroid gland. Where does it come from? I-131 is produced commercially for medical and industrial uses through nuclear fission. It also is a byproduct of nuclear fission processes in nuclear reactors and weapons testing.
What is the ½ life of iodine 131?
The 131I isotope has a half-life of 8 days and emits γ radiation and β particles. Given orally, it is concentrated in the thyroid, where the β particles destroy the gland. Symptoms of hyperthyroidism begin to improve in a few days to a few weeks, but 2 to 3 months are often required for a complete effect.
What is the half value layer of lead?
Shielding Layer Examples
| Half-Value Layer (cm) | ||
|---|---|---|
| Radioisotope | Gamma (MeV) | Lead |
| Cesium-137 | 0.66 | 0.7 |
| Cobalt-60 | 1.17, 1.33 | 1.2 |
How iodine-131 is used as a tracer?
Radioactive iodine (I-131), an isotope of iodine that emits radiation, is used for medical purposes. When a small dose of I-131 is swallowed, it is absorbed into the bloodstream in the gastrointestinal (GI) tract. It is concentrated from the blood by the thyroid gland, where it begins destroying the gland’s cells.
How is iodine 123 used in medicine?
Sodium Iodide I-123 is a radioactive isotope of iodine used in nuclear medicine for the diagnostic study of thyroid disease. Following oral administration, I-123 is absorbed through the gastrointestinal tract and is taken up by the thyroid gland.
How is iodine used in medicine?
Iodine is used to treat and prevent iodine deficiency and as an antiseptic. For iodine deficiency it can be given by mouth or injection into a muscle. As an antiseptic it may be used on wounds that are wet or to disinfect the skin before surgery.
Which field is iodine-131 useful?
…radionuclides suitable for metabolic studies, iodine-131 is one of the most widely used. This gamma-ray emitter has a half-life of eight days and concentrates in the thyroid gland, and so provides a measure of thyroid function.
Why is iodine-131 harmful?
I-131 collects in the thyroid gland. People exposed to I-131, especially during childhood, may have an increased risk of thyroid disease, including thyroid cancer. Thyroid cancer is uncommon and is usually curable. Typically, it is a slow-growing cancer that is highly treatable.
What are the side effects of iodine-131?
Common side effects of Sodium Iodide I 131 include nausea, vomiting, chest pain, rapid heart rate, itching skin, rash, and hives. Dosing of Sodium Iodide I 131 ranges widely from 5 to 1000 microcuries, depending on the procedure being performed.
What is the purpose of half value layer?
Half-value layer (HVL) is the width of a material required to reduce the air kerma of an x-ray or gamma ray to half its original value. This applies to narrow beam geometry only. With broad-beam geometry, a greater amount of scatter will reach the detector, falsely overestimating the degree of attenuation.
What is the half life of iodine 131?
Iodine-131 is a beta and gamma emitter. The energies of both are significant, so quite high dose rates are emitted by this nuclide, and the gamma radiation is quite penetrating. The half-life is 8 days, so over the likely period of use of the material, there is not a large reduction in activity. There can therefore be
What is the half value layer in radiation protection?
3. Half Value Layer The half value layer (HVL) is the thickness of a shielding material required to reduce the intensity of radiation at a point to one half of its original intensity. It can be calculated by setting I = ½ I 0 and solving the attenuation equation for x: 0.5 e x 1/ 2 x 1/2 = ln(0.5) x 1/2 = 0.693 = HVL
How to calculate the exposure rate of iodine-131?
The unshielded exposure rate from 37 megabecquerels (MBq) of iodine-131 is 5.8 E-8 Coulomb/kilogram/hour (C/kg/hr) at 1 meter. To calculate the exposure from iodine-131, multiply 5.8 E-8 by the activity of the source (A) in MBq, divide by the square of the distance (d) in meters, and multiply by the time of exposure (t) in hours.
What is the net attenuation of iodine 131?
However, the buildup factor (including scatter from broad beam conditions) would be 8.9, resulting an a net attenuation of 0.24. Of course, iodine-131 is multienergetic and the calculation for shielding for iodine-131 is more complicated.