structures in the dermis and subcutaneous tissue such as sweat glands,hair follicles and nerve endings, as well as the vasculature. Resulting progressive endarteritis obliterans can lead to ischemicpain, ulceration, and at higher doses to irreversible tissue necrosis. 3.2.2.3 Contamination Contamination with radioactive materials alone is unlikely to cause symptoms of ARS, although clinical signs of bone marrow depression and oligospermia are possible depending on the amountandradiological characteristics of the contaminant andits disposition on or in the body. It can result in local radiation-induced burns of the skin at the contaminated site. 3.2.3. Delayed Clinical Features Somedeterministic effects of acute radiation exposure may not becomeclinically evident for several months or years post-exposure; these include: 3.2.3.1 Vascular sclerosis, fibroatrophy Endothelialcells lining blood vessels are sensitive to radiation at doses above 5 Gy. Death of these cells predisposes to vascular sclerosis with the eventual reduction orelimination of the blood supply to dependent tissues; such tissues ultimately atrophy. Evidence of these delayed changes may be observed within two or more months after irradiation of skin at doses 6 Gy and higher. . 3.2.3.2 Cataracts Radiation-induced cataracts are associated with exposure of the lens to an acute radiation dose of about 2 Gy or more, or a protracted dose totally about 1.1 Gy over a period of months. Theinterval between the exposure and cataract formation ranges from about 10 months up to approximately 30 years, depending on the dose and dose-rate.