Gamma ray sterilization

Gamma rays from cobalt-60 are also used to sterilize food, since they kill bacteria. The gamma rays are incapable of inducing radioactivity within the food, so the method is potentially clean . The rays do, however, produce some free radicals, which are potentially harmful substances. But the concentrations of these are very small, and they may well do less harm than the preservatives... 

Once radioactive decay starts, it continues until all the atoms have reached a stable state. The radioisotope can only be shielded to prevent exposure to the radiation. The most common applications of gamma rays are sterilization of single-use medical supplies, elimination of organisms from pharmaceuticals, microbial reduction in and on consumer products, cancer treatment, and processing of polymers (cross-linking, polymerization, degradation etc.). 

The use of ionizing radiation as a way to sterilize the environment and prevent oral transmission of this parasite also showed no practical application (Dias, 2006). The use of gamma rays on infected blood at an exposure of 5000 rad was not sufficient to inactivate the parasite, and studies with doses of 90 krad showed a loss of virulence, but not complete killing of the parasite (Amato Neto et al., 1996 Salata et al., 1973). Takeda et al. (1986) suggested that the gamma radiation dose to kill T. cruzi could be between 200 and 300 krad (Takeda et al., 1986). 

This process prolongs the shelf-life of the food, but sometimes changes the taste. Gamma rays are also used to sterilize hospital equipment, especially plastic syringes that would be damaged if heated. 

Researchers are also exploring ways of using inorganic materials, especially those closely related to natural hone material, for artificial bone filling. Interpore International of Irvine, California, for example, received approval in 1992 for its hydroxyapatite-based hone substitute called Pro Osteon. The material is made from coral that has been heated to temperatures of about 2000°C to obtain hydroxyapatite (a primary component of coral) of 95 percent purity. The material is then formed into a scaffolding resembling natural bone, and this final product is irradiated with gamma rays to sterilize it. 

We can use the effects of radiation for good as well as evil. Radioactive isotopes of elements can be used in specific apparatus to focus their radiation on unwanted body material and cancerous cells. Often the gamma rays from the 60 isotope of cobalt (27C0) are used to produce these penetrating rays to kill cancer cells. This same isotope is also used to produce the gamma rays to sterilize medical instruments. It kills the germs but the instruments remain unaffected. 

Radiation sterilization includes the use of the ionizing radiation of x-rays and gamma-rays. The former are derived from bombardment of a heavy metal target with electrons. Gamma-rays are obtained from atomic nucleus decay from excited to ground state. 

Several types of radiation find a sterilizing application in the manufacture of pharmaceutical and medical products, principal among which are accelerated electrons (particulate radiation), gamma-rays and UV light (both electromagnetic radiations). The major target for these radiations is believed to be microbial DNA, with damage occur -... 

The pesticide DDT is toxic to humans and animals repeatedly exposed to it. DDT persists in the environment for a long time. It concentrates in fatty tissues. The DDT once used to control the screwworm fly was replaced by a radiological technique. Irradiating the male flies with gamma rays alters their reproductive cells, sterilizing them. When great numbers of sterilized males are released in an infested area, they mate with females, who, of course, produce no offspring. This results in the reduction and eventual disappearance of the population. 

The sandpaper abrasion kit consists of 10 sheets of singleuse sandpaper (3M Wet-or-Dry P220) sterilized with gamma rays and a yellow disinfecting and healing powder bismuth subgallate. 

The abrasion is carried out with 3M Wet-or-Dry sandpaper, P220, sterilized with gamma rays. It should be gentle, steady, careful and even (intersect each pass) and be stopped as soon as the patient feels pain. 

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