Author/Authors :
R. AZARI، MANSOUR نويسنده Department of Occupational Hygiene, School of Public Health, Safety Promotion & Injury Prevention Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran , , Yazdian ، Asil نويسنده Department of Occupational Hygiene, College of Public Health , , ZENDEHDEL، REZVAN نويسنده Department Of Occupational Health engineering, School of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran , , Souri ، Hamid نويسنده Safety Promotion and Injury Prevention Research Center , , Khodakarim ، Soheila نويسنده Department of Occupational Hygiene, College of Public Health , , Peirovi ، Habibalalah نويسنده Medical Nanotechnology & Tissue Engineering Research Center , , Panahi ، Davod نويسنده Department of Occupational Hygiene, College of Public Health , , KAZEMPOUR، MARZIEH نويسنده Dept of Occupational Health Eng, Faculty of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran ,
Abstract :
Background: In recent years, some studies have tried to improve Phase Contrast Microscopy (PCM) for counting asbestos fibers. Due to the lack of a universally accepted alternative method, this study aimed to improve PCM for better counting of asbestos fibers.
Materials and Methods: Confirmed asbestos standards were applied using a dust generator for sampling. Sampling from the dust generator was carried out according to the Occupational Safety and Health Administration (OSHA) ID-160 method and 95 samples with diverse densities were prepared to be counted using conventional and modern PCM. All samples were counted single blindly by a co-author of this study and the obtained data were analyzed by paired t-test, correlation coefficient and Bland-Altman analysis. Duplicate samples were prepared for qualitative analysis by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X ray.
Results: Asbestos densities on filters were in the range of less than 100 to 600 fibers/mm2. Statistically, significant differences were observed for the count density of the 95 samples counted by the two phase contrast microscopes (P < 0.001). Nikon microscope demonstrated higher counts compared to conventional microscope and had a lower coefficient of variation. Samples were analyzed qualitatively using FT-IR and SEM, and the presence of asbestos fibers was confirmed.
Conclusion: The improved PCM and FT-IR methods presented in this study demonstrated more precise and accurate determination of personal exposure to airborne asbestos fibers and subsequent risk assessment.
