Radiochemical dating chemistry

The portion of the total radiation activity (in air) contributed by each isotope versus time after the Chernobyl disaster, at the site.Note the prominence of radiation from I-131 and Te-132/I-132 for the first week.Nevertheless, it now serves as a groundwater tracer as indicator of nuclear waste dispersion into the natural environment.In a similar fashion, I to enter the biosphere as it becomes incorporated into vegetation, soil, milk, animal tissue, etc.Iodine-129 (I; half-life 15.7 million years) is a product of cosmic ray spallation on various isotopes of xenon in the atmosphere, in cosmic ray muon interaction with tellurium-130, and also uranium and plutonium fission, both in subsurface rocks and nuclear reactors.Artificial nuclear processes, in particular nuclear fuel reprocessing and atmospheric nuclear weapons tests, have now swamped the natural signal for this isotope.These are I (half-life 8 days) is one of the common radioactive fission-products of nuclear fission, and is thus produced inadvertently in very large amounts inside nuclear reactors.

Since I, which has no beta activity, is more suited for routine nuclear medicine imaging of the thyroid and other medical processes and less damaging internally to the patient.Historically, I was the first extinct radionuclide to be identified as present in the early solar system.Its decay is the basis of the I-Xe iodine-xenon radiometric dating scheme, which covers the first 85 million years of solar system evolution.The beta particles emitted by the radioisotope destroys the associated thyroid tissue with little damage to surrounding tissues (more than 2.0 mm from the tissues absorbing the iodine).

Due to similar destruction, I is the iodine radioisotope used in other water-soluble iodine-labeled radiopharmaceuticals (such as MIBG) used therapeutically to destroy tissues.

A Pheochromocytoma is seen as a dark sphere in the center of the body (it is in the left adrenal gland).