EXPERIMENTAL PNEUMOCONIOSIS OF SANDBLASTING SUBSTITUTES

在喷漆前使用喷砂来清洁钢结构 与严重和快速进展的矽肺有关。高发病率 而且在暴露后的几年内就注意到了死亡率。这个 美国劳工部估计，从事这项工作的工人人数 喷沙量达到78,000。对这些危险的认识导致了 欧洲和澳大利亚禁止喷砂；在美国，喷砂 替代品现在越来越多地被使用。它们是从煤中提取的。 来自熔炉的灰渣和炉渣，包括各种 铁、铝、钙、镁和钛的无定形硅酸盐的比例。《自由》 二氧化硅含量仅为0.03%。 本项目的目标是开发一种大鼠模型来评估 沙粒替代物的肺纤维化潜能。肝纤维化的作用 长期接触替代品将在两种正常情况下进行调查 和矽肺大鼠。将在一组中诱发矽肺，然后是 暴露于替代品；第二组将仅暴露于 替身。暴露后，两组人都将接受额外的 十二个月。将维持适当的控制组大鼠 比较。大鼠将被连续处死进行组织学检查， 生化测定胶原蛋白，并评价组织矿物质含量。 这项研究将首次评估这些替代品的安全性。 我们相信这一大鼠模型将在描绘和识别 预测磨料抛光机潜在的职业危害 而且没有先前存在的矽肺。职业暴露标准为 基于假设任何特定代理人的风险不是 受其他环境因素影响。这项研究将 提供有关生物来源的肺纤维化风险的重要信息 不同吸入剂之间的相互作用，这可能会影响 职业标准的未来发展。更具体地说，这是 如果发生以下情况，该项目将显示矽肺进展的风险增加 矽肺喷沙机使用这些替代品。

The use of sandblasting to clean steel structures before applying paint is associated with severe and rapidly progressive silicosis. High morbidity and mortality rates have been noted within a few years of exposure. The U.S. Department of Labor has estimated the number of workers engaged in sandblasting to be 78,000. Recognition of these hazards led to the prohibition of sandblasting in Europe and Australia; in the U.S., sand substitutes are now increasingly being used. They are derived from coal ash residues and slag from smelting furnaces, and comprise various proportions of amorphous silicates of Fe, Al, Ca, Mg and Ti. The free silica content is only 0.03%. The objective of this project is to develop a rat model to assess the pulmonary fibrogenic potential of sand substitutes. Fibrotic effect from prolonged exposure to the substitutes will be investigated in both normal and silicotic rats. Silicosis will be induced in one group, followed by exposure to the substitute; the second group will be exposed only to the substitute. After exposure, both groups will be followed for an additional twelve months. Appropriate control rats will be maintained for comparisons. Rats will be sequentially sacrificed for histologic, biochemical assay of collagen, and tissue mineral content evaluations. This study will assess for the first time the safety of these substitutes. We believe this rat model will have application in delineating and predicting the potential occupational hazards for abrasive blasters with and without pre-existing silicosis. Occupational exposure standards are based on the assumption that the risk of any particular agent is not influenced by exposure to other environmental factors. This study will provide important information on the risk of lung fibrosis from biologic interactions between different inhaled agents, which could affect the future development of occupational standards. More specifically, this project will demonstrate increased risk of progression of silicosis if silicotic sandblasters use these substitutes.