Abstract

Mobilization of asbestos fibers from a 60-year-old corrugated asbestos cement roof was studied in material samples collected from a domestic house in Southern-Norway. Samples included pieces of the roof itself, rainfall simulated run off-water and moss growing on the roof surface. Weathered roof debris below the rain water system was investigated for asbestos fibers leached from the roof, and air samples were collected for asbestos concentrations in ambient air. Micrographs obtained by scanning electron microscopy show that weathering exposed asbestos fibers on the deteriorated roof surface. A high number of fibers found in the run off-water as well as in the weathered roof debris sample illustrates that exposed fibers are prone to mobilization. Investigation of weathering-induced magnesium depletion by scanning electron microscopy energy dispersive X-ray spectroscopy of asbestos fibers collected from the moss, roof underside and surface revealed that fibers had MgO weight % comparable to reference material. The major element chemistry of the fibers is therefore unaltered. Our findings demonstrate that care must be taken when working on and handling old corrugated asbestos cement roof as asbestos fibers might be released. In order to limit exposure to mobile fibers, moss covering asbestos cement roof should not be removed.

摘要

在从挪威南部的一所住宅中收集的材料样本中研究了石棉纤维从 60 年历史的波纹石棉水泥屋顶中的动员。样本包括屋顶本身的碎片、模拟雨水径流和屋顶表面生长的苔藓。对雨水系统下方风化的屋顶碎片进行了调查，以了解从屋顶浸出的石棉纤维，并收集空气样本以了解环境空气中的石棉浓度。通过扫描电子显微镜获得的显微照片表明，老化的屋顶表面暴露了石棉纤维。在流出的水和风化的屋顶碎片样本中发现的大量纤维表明暴露的纤维易于移动。通过对从苔藓、屋顶下侧和表面收集的石棉纤维进行扫描电子显微镜能量色散 X 射线光谱研究，对风化引起的镁消耗进行了研究，结果表明纤维的 MgO 重量百分比与参考材料相当。因此，纤维的主要元素化学没有改变。我们的研究结果表明，在处理和处理旧的瓦楞石棉水泥屋顶时必须小心，因为石棉纤维可能会释放出来。为了限制接触移动纤维，不应去除覆盖石棉水泥屋顶的苔藓。我们的研究结果表明，在处理和处理旧的瓦楞石棉水泥屋顶时必须小心，因为石棉纤维可能会释放出来。为了限制接触移动纤维，不应去除覆盖石棉水泥屋顶的苔藓。我们的研究结果表明，在处理和处理旧的瓦楞石棉水泥屋顶时必须小心，因为石棉纤维可能会释放出来。为了限制接触移动纤维，不应去除覆盖石棉水泥屋顶的苔藓。