Beryllium
描述
Beryllium is a light-weight metallic element, which was first recognized as a lung hazard in Europe in the 1930s, shortly after its first production in modern industry. People exposed to beryllium compounds are at increased risk of developing beryllium sensitization and chronic beryllium disease (CBD). The chronic lung disease was first described among workers exposed to beryllium-containing materials used in the manufacture of fluorescent lamps. In primary production of beryllium metal, which was used in nuclear weapons components, physicians recognized severe dermatitis, reversible pneumonitis, and chronic granulomatous lung disease. Physiologically, this metal/element exists as an ion in the body. It is now recognized that the physicochemical properties of beryllium compounds may account for the differing clinical presentations in different industries. In primary production of beryllium metal, soluble salts are present and cause rashes in approximately one fourth of exposed workers and reversible acute pneumonitis in a smaller portion of the workforce. After heavy inhalation exposures, radiographic abnormalities evolve at approximately three weeks; resolution of symptoms and radiologic abnormalities away from exposure occur only after months, but symptoms recur immediately upon reexposure. The granulomatous nature of chronic beryllium disease is now known to be caused by cell-mediated sensitization to beryllium. Chronic beryllium disease (CBD) is a granulomatous lung disorder characterized by the accumulation of beryllium-specific CD4(+) T cells. Depending on genetic susceptibility and the nature of the exposure, CBD occurs in up to 20% of exposed workers. Genetic susceptibility has been associated with particular HLA-DP alleles, especially those possessing a negatively charged glutamic acid residue at the 69th position of the beta-chain. The mechanism for this association lies in the ability of these HLA-DP molecules to bind and present beryllium to pathogenic CD4(+) T cells. Large numbers of effector memory, beryllium-specific CD4(+) T cells are recruited to the lung of these subjects and secrete Th1-type cytokines upon beryllium recognition. The presence of circulating beryllium-specific CD4(+) T cells directly correlates with the severity of lymphocytic alveolitis. Since 1987, this biomarker of sensitization has enabled medical surveillance of beryllium-exposed workforces. Beryllium lymphocyte proliferation tests have been used to screen workers to detect sensitization, to characterize epidemiologically workplace risks for beryllium sensitization, and to evaluate the effectiveness of interventions intended to prevent sensitization. The most compelling real-world example of genetic testing for susceptibility to a workplace exposure involves those industries that process or fabricate beryllium. Under reasonable assumptions, the longitudinal positive predictive value of the HLA-DPB1-Glu69 marker of susceptibility to beryllium disease is 12%. Interpretive challenges further limit the utility of the test and may inadvertently suggest a false sense of safety among workers. Reduction in inhalation exposure to beryllium has not resulted in a concomitant reduction in the occurrence of beryllium sensitization or CBD, suggesting that continued prevalence may be due, in part, to unchecked skin exposure to beryllium-containing particles. (A7679, A7681, A7682).
类别
"Cigarette Toxin", "Industrial/Workplace Toxin", "Pollutant", "Airborne Pollutant", "Food Toxin", "Natural Toxin"
同义词
"Be(2+)", "Be2+", "Berylliium(II) cation", "Beryllium ion", "Beryllium(2+)", "Beryllium(2+) ion", "Beryllium(II)", "Beryllium(II) ion"
IUPAC 名称
beryllium(2+) ion
InChI 标识符
InChI=1S/Be/q+2
键
InChIKey=PWOSZCQLSAMRQW-UHFFFAOYSA-N
化合物类型
Inorganic compounds
大分类
Homogeneous metal compounds
类型
Homogeneous alkaline earth metal compounds
直接大类
Homogeneous alkaline earth metal compounds
取代基
"Homogeneous alkaline earth metal"
外部描述符
"a cation", "beryllium cation", "divalent metal cation", "monoatomic dication"
地位
Detected and Not Quantified
蜂窝位置
"Cytoplasm", "Extracellular"
毒性机制
Once in the body, beryllium acts as a hapten and interacts with human leucocyte antigen (HLA) DP presenting cells in the lungs, becoming physically associated with a major histocompatability (MHC) class II molecule. This MHC class II-beryllium-peptide complex is recognized by the T lymphocyte receptor, triggering CD4+ T lymphocyte activation and proliferation. The resulting inflammatory response is a cell-mediated process orchestrated by cytokines and results in the formation of (usually pulmonary) granulomas. Beryllium's toxicity may be controlled by the iron-storage protein ferritin, which sequesters beryllium by binding it and preventing it from interacting with other enzymes. (L25, A37, A91)
代谢
Beryllium is absorbed mainly through the lungs, where it enters the bloodstream and is transported throughout the body by binding to prealbumins and γ-globulins. Beryllium accumulates in lung tissue and the skeleton. It is excreted mainly in the urine. (L25)
致癌性
1, carcinogenic to humans. (L135)
用途/来源
Beryllium is purified for use in nuclear weapons and reactors, aircraft and space vehicle structures, instruments, x-ray machines, and mirrors. Beryllium ores are used to make speciality ceramics for electrical and high-technology applications. Beryllium is often found in alloys which are used in automobiles, computers, sports equipment, and dental bridges. (L24)
最低风险等级
Chronic Oral: 0.002 mg/kg/day (L134)
健康影响
Acute inhalation of a high level of beryllium can result in a pneumonia-like condition called acute beryllium disease. Chronic inhalation of beryllium can caused an inflammatory reaction in the respiratory system called chronic beryllium disease. Chronic beryllium disease may result in anorexia and weight loss, as well as right side heart enlargement and heart disease in advanced cases. Chronic exposure can also increase the risk of lung cancer. Skin contact with beryllium results in contact dermatitis.
(L24, L25)
症状
Chronic beryllium disease causes fatigue, weakness, difficulty breathing, and a persistent dry cough.
(L24, L25)
治疗
Chronic beryllium disease is treated with immunosuppressive medicines, usually of the glucocorticoid class. (L24)
维基百科链接
http://en.wikipedia.org/wiki/Beryllium
创建于
2009-03-06 18:57:58 UTC
更新于
2014-12-24 20:20:57 UTC