Abstract:
From 1954 to 1983, a vermiculite processing facility operated near the Honolulu airport and processed raw material from the Libby, Montana mine, which is now well known for the high asbestos content of its clay deposits. The factory was closed in 1983 due to health hazard concerns, and remediation was performed in 2001 as part of the Libby mine superfund project. However, because of close proximity of the closed-down facility to residential areas of metropolitan Honolulu, some concerns remain regarding the possible environmental persistence of the harmful contaminant. To assess the dispersion of asbestos-contaminated vermiculite and explore the impact of trade winds on its distribution, air samples, and soil samples were collected from multiple locations near the former vermiculite plant. Polarized light microscopy was employed to identify elongated minerals, including potential asbestos. Quantitative mineralogical analysis utilizing X-ray powder diffraction and Rietveld refinement revealed an average content of approximately 7% vermiculite and 4% tremolite at the site. The asbestiform nature of tremolite was confirmed through X-ray micro-diffraction. Detailed analysis of airborne samples using transmission electron microscopy revealed no detectable levels of asbestos fibers in the vicinity of the former processing facilities, but the possibility of asbestos fibers becoming airborne due to mechanical disturbance during dry weather cannot be ruled out.
摘要:
从1954年到1983年,在檀香山机场附近运营的蛭石加工设施,加工了利比的原材料,蒙大拿矿,这是现在众所周知的高石棉含量的粘土沉积物。该工厂于1983年因健康危害而关闭,作为Libby矿山超级基金项目的一部分,于2001年进行了修复。然而,因为关闭的设施靠近檀香山大都市的住宅区,关于有害污染物的可能的环境持久性,仍然存在一些担忧。评估受石棉污染的蛭石的散布情况,并探讨信风对其分布的影响,空气中的灰尘,土壤样本是从前蛭石植物附近的多个位置收集的。偏振光显微镜用于识别细长的矿物,包括潜在的石棉。利用X射线粉末衍射和Rietveld精修进行的定量矿物学分析显示,该地点的平均含量约为7%蛭石和4%透闪石。通过X射线微衍射证实了透闪石的石棉质性质。使用透射电子显微镜对空气中的灰尘样品进行详细分析,发现在以前的处理设施附近没有可检测到的石棉水平,但是不能排除在干燥天气下由于机械干扰而导致石棉纤维空气传播的可能性。