Which isotope is primarily used for blood irradiation?

Cobalt-60 is primarily used for blood irradiation due to its properties and the specific needs of the procedure. This isotope emits gamma radiation, which is effective in sterilizing blood products by inactivating pathogens while preserving the blood's essential components and functionality.

Cobalt-60's half-life of about 5.27 years allows it to be used efficiently in clinical settings, as it provides a stable source of radiation over a relatively extended period. This isotopic characteristic makes cobalt-60 suitable for applications where maintaining a consistent dose of radiation is crucial for safety and efficacy in blood products.

Other isotopes, like cesium-137, iodine-131, and iridium-192, have different applications in medical therapy and diagnostics, but they are not primarily utilized for blood irradiation. Cesium-137 is more commonly associated with radiation therapy for certain cancers, iodine-131 is widely used in thyroid treatments, and iridium-192 is primarily used in brachytherapy for cancer treatments. Each of these isotopes has specific uses that do not align with the requirements for blood irradiation, highlighting cobalt-60's unique appropriateness for this medical application.