Levels high enough to cause burn are generally lethal if received as a whole-body dose, whereas they may be treatable if received as a shallow or local dose. Medical imaging
Fluoroscopy may cause burns if performed repeatedly or for too long.Similarly, X-ray computed tomography and traditional projectional radiography have the potential to cause radiation burns if the exposure factors and exposure time are not appropriately controlled by the operator. A study of radiation-induced skin injuries has been performed by the Food and Drug Administration (FDA) based on results from 1994, followed by an advisory to minimize further fluoroscopy-induced injuries. The problem of radiation injuries due to fluoroscopy has been further investigated in review articles in 2000, 2001, 2009 and 2010. Radioactive fallout
Beta burns are frequently the result of exposure to radioactive fallout after nuclear explosions or nuclear accidents. Shortly after the explosion, the fission products have very high beta activity, with about two beta emissions per each gamma photon. After the Trinity test, the fallout caused localized burns on the backs of cattle in the area downwind. The fallout had the appearance of small flaky dust particles. The cattle showed temporary burns, bleeding, and loss of hair. Dogs were also affected; in addition to localized burns on their backs, they also had burned paws, likely from the particles lodged between their toes as hoofed animals did not show problems with feet.
Inhalation of beta radioactive isotopes may cause beta burns of lungs and nasopharyngeal region, ingestion may lead to burns of gastrointestinal tract; the latter being a risk especially for grazing animals. In first degree beta burns the damage is largely limited to epidermis. Dry or wet desquamation occurs; dry scabs are formed, then heal rapidly, leaving a depigmented area surrounded with irregular area of increased pigmentation. The skin pigmentation returns to normal within several weeks. Second degree beta burns lead to formation of blisters. Third and fourth degree beta burns result in deeper, wet ulcerated lesions, which heal with routine medical care after covering themselves with dry scab. In case of heavy tissue damage, ulcerated necrotic dermatitis may occur. Pigmentation may return to normal within several months after wound healing.Lost hair begins regrowing in nine weeks and is completely restored in about half a year.The acute dose-dependent effects of beta radiation on skin are as follows:
According to other source:
As shown, the dose thresholds for symptoms vary by source and even individually. In practice, determining the exact dose tends to be difficult. Similar effects apply to animals, with fur acting as additional factor for both increased particle retention and partial skin shielding. Unshorn thickly wooled sheep are well protected; while the epilation threshold for sheared sheep is between 23 and 47 Gy (2500–5000 rep) and the threshold for normally wooled face is 47–93 Gy (5000–10000 rep), for thickly wooled (33 mm hair length) sheep it is 93–140 Gy (10000–15000 rep).