Faculty of Public Health, Mahidol University, Bangkok, Thailand.
Saf Health Work. 2012 Sep;3(3):235-40. doi: 10.5491/SHAW.2012.3.3.235. Epub 2012 Aug 30.
The objectives are to compare the airborne asbestos concentrations resulted from mitering of abestos cement roof sheets by a high-speed motor and a hand saw, and to monitor whether other workers near the test sites are vulnerable to the fibers exceeding the occupational exposure limit. Four test cases were carried out and altogether 7 personal and 4 area air samples were collected. The NIOSH method 7400 was employed for the air samplings and analysis. Using the phase contrast microscopy, fiber counting was conducted under Rule A. The study showed that the fiber concentration medians for personal air samples gathered from the two tools were 4.11 fibers/cc (ranged: 1.33-12.41 fibers/cc) and 0.13 fibers/cc (ranged: 0.01-5.00 fibers/cc) respectively. The median for the area samples was 0.59 fibers/cc (ranged: 0.14-3.32 fibers/cc). Comparing each study case, the concentration level caused by the high-speed motor saw was more than twice that of the hand saw. According to the area samples, the workers nearby the test site are at risk from high exposure to asbestos.
目的是比较用高速电机和手锯斜切石棉水泥屋顶板产生的空气中石棉浓度，并监测测试现场附近的其他工人是否容易接触到超过职业接触限值的纤维。进行了四个测试案例，共采集了 7 个人和 4 个区域的空气样本。使用 NIOSH 方法 7400 进行空气采样和分析。采用相差显微镜，根据规则 A 进行纤维计数。研究表明，两种工具采集的个人空气样本中的纤维浓度中位数分别为 4.11 纤维/cc（范围：1.33-12.41 纤维/cc）和 0.13 纤维/cc（范围：0.01-5.00 纤维/cc）。区域样本的中位数为 0.59 纤维/cc（范围：0.14-3.32 纤维/cc）。比较每个研究案例，高速电机锯产生的浓度水平是手锯的两倍多。根据区域样本，测试现场附近的工人面临高暴露于石棉的风险。
