微波消解-电感耦合等离子体质谱法测定胶囊中的铬

本文通过对胶囊进行预处理,建立了ICP-MS法测定胶囊中铬含量的检测方法。该方法检出限为0．18μg／L,精密度RSD为0．8％。该方法灵敏、准确、可靠,对控制胶囊中铬元素的含量有实际意义。     

2010—2012年江苏某市铬接触作业环境铬浓度与工人鼻检查异常调查

[目的]了解江苏省张家港市镀铬企业生产环境状况和铬接触作业工人鼻黏膜损伤情况,提出监督管理措施。[方法]通过抽样调查和对调查对象的工作场所空气中铬浓度检测、作业人员职业健康检查,比较、分析接触条件下的损害有无剂量-效应关系。[结果]在车间环境铬检测浓度符合国家职业卫生标准,甚至低于检测限（0.01 mg/m3）的情况下,仍然有部分镀铬操作工人发生鼻部病变,鼻检查异常率为13.11%。[结论]现有铬及其化合物的采样、检测、评价标准已经不能完全匹配当前保护操作工人的健康需求,有必要对现有标准进行探讨研究。     

Hexavalent chromium and isocyanate exposures during military aircraft painting under crossflow ventilation

Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers (“hosemen”). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 µg/m³, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m³, and 7 out of 12 exceeded the threshold limit value of 10 µg/m³, with means 38 µg/m³ for sprayers and 8.3 µg/m³ for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/m³ for hosemen. Total reactive isocyanate group—the total of monomer and oligomer as NCO group mass—showed 6 of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 µg/m³, with means 50.9 µg/m³ for sprayers and 7.29 µg/m³ for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m³/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m³/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re-circulations, turbulence, and fugitive emissions, while wasting energy. Smoke releases showing more effective ventilation here than in other aircraft painting facilities carries technical feasibility relevance.     

有机铬对实验性糖尿病大鼠胰腺保护作用的观察

目的：观察有机铬对实验性糖尿病大鼠胰腺的保护作用。方法：用灌胃的方式增加糖尿病大鼠体内的有机铬含量,观察灌胃12周后糖尿病大鼠的血糖浓度、血清胰岛素浓度及胰腺的病理改变。并与正常大鼠及未治疗组大鼠加以比较。结果：治疗组大鼠血糖浓度及血清胰岛素浓度与未治疗组相比具有明显差异。胰腺组织结构改善明显。结论：有机铬能保护糖尿病鼠胰腺组织．增加血清胰岛素,降低血糖。     

微量元素铬 镍与人体健康

铬和镍是人体中必需的微量元素。对铬和镍与人体健康的关系进行了论述,包括:铬和镍在人体内的存在与分布、生理功能、代谢及对人体健康的影响。     

Effects of repeated Cr(VI) intratracheal instillation on club (Clara) cells and activation of nuclear factor-kappa B pathway via oxidative stress

Hexavalent chromium [Cr(VI)] exposure is known to induce respiratory inflammation and contribute to lung cancer development, but little is known about its target cell type in lung. In the current study, we investigated the effects of repeated Cr(VI) intratracheal instillation on club (Clara) cells and club (Clara) cell secretory protein (CC16) in rats and explored whether the nuclear factor-kappa B (NF-κB) related pathway was involved. We also studied the role of orally delivered Zn against Cr-induced adverse health effects. For four weeks, sixty Sprague-Dawley male rats received weekly intratracheal instillation of potassium dichromate (K₂Cr₂O₇) at 0, 0.063 and 0.630 mg Cr/kg with or without daily intragastric administration of zinc sulfate (ZnSO₄) at 10 mg Zn/kg. Results showed that exposure to Cr(VI) significantly increased the organ coefficient of lung (organ weight as a percentage of body weight), albumin and total protein level in bronchoalveolar lavage fluid (BALF), indicating lung injury and compromised bronchoalveolar/blood barrier (BA/BB) integrity. With increasing Cr(VI) dose, the secretion of CC16 decreased in a dose-dependent manner, suggesting that CC16 can serve as a peripheral biomarker for club cell damage during early lung injury induced by Cr(VI). Increased expression of NF-κB were observed in club cells in both Cr-exposed groups, indicating upregulation of NF-κB, which can be induced by reactive oxygen species (ROS) generated by club cells during Cr reduction with repetitive Cr(VI) exposure. Cr-induced DNA damage was also observed, as significant increase of 8-OHdG was found with Cr exposure at 0.630 mg/kg week. Oral Zn supplementation did not alleviate changes in serum CC16 level under Cr(VI) exposure, indicating its failure in protecting against Cr(VI)-induced club cell damage.     

Comparison of the protective effects of antioxidant compounds in the liver and kidney of Cd‐ and Cr‐exposed common carp

The aim of this study was to see whether the taurine (TAU), alpha‐lipoic acid (LA), curcumin (CUR), and N‐acetylcysteine (NAC) protection against oxidative stress caused by heavy metals is owed to the metal‐decreasing or antioxidative effect. In this context, liver and kidney tissues of common carp (Cyprinus carpio carpio L.) were exposed in vivo to model toxicants cadmium (Cd) and chromium (Cr). The tissues were dissected 96 h after intraperitoneal injection of the metals and antioxidant substances. Cd and Cr levels were determined in the liver using the ICP‐OES, but we could not obtain enough kidney tissue to make the same measurements in the kidney. The enzymatic activities of SOD, CAT, and GPx, and the GSH redox status and lipid peroxidation levels were analyzed using spectrophotometric methods. Of all investigated antioxidants, only NAC decreased metal levels in the liver. Cd had little effect on oxidative stress parameters, while Cr showed a weak prooxidative effect. Cotreatment with TAU/LA/CUR/NAC and Cr significantly increased liver SOD activity. Chromium induced kidney SOD and CAT, but all antioxidants lowered CAT activity. Cadmium reduced liver and increased kidney GSSG. NAC increased liver GSH, but the increase did not correlate with decrease in Cd. Curcumin given with Cd increased kidney and decreased liver lipid peroxidation, whereas TAU with Cr increased lipid peroxidation in both tissues. N‐Acetylcysteine was the most effective antioxidative agent, owing to its metal‐decreasing function as well as to its effects on the GSH redox status. We believe that the investigated antioxidant substances which may have been involved in the reduction of Cr caused an increase in SOD activity and a decrease in CAT activity. Changes in the GSSG levels in both tissues might be an adaptive response to the prooxidative potential of Cd. Because of their respective tissue‐ and metal‐dependent prooxidative effects, CUR and TAU deserve particular attention in regard to their use against metal toxicity, Cr in particular. © 2011 Wiley Periodicals, Inc. Environ Toxicol 29: 129–137, 2014.