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Title:	Evaluation of direct and indirect sampling method for respirable crystalline silica compliance monitoring among granite quarries workers in Kuala Lumpur and Selangor
Authors:	Suhaily Amran (P72189)
Supervisor:	Mohd Talib Latif, Prof. Dr.
Keywords:	Respiratory organs Respiration Cardiovascular system Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	24-Jan-2019
Description:	Due to its toxicity and carcinogenic properties, many countries set occupational exposure limits for respirable crystalline silica-quartz (RCS-quartz) at very low levels, ranging between 0.025 and 0.1 mg/m3. This situation poses a big challenge to industrial hygienists and hygiene chemist in selecting and applying suitable sampling methods which are capable of measuring such low exposure limit. This may include selection between direct or indirect sampling methods with consideration to the accuracy of results imposed by each method. The aim of this study is to evaluate analytical performance characteristic and differences between RCS-quartz exposure resulting from direct and indirect methods; To evaluate the variability of respirable crystalline silica (RCS)-quartz exposure caused by different sampling method and environmental factors and finally assess the compliance status on respirable dust and RCS-quartz exposure among granite crusher operators based on the method with better performance characteristic. At the beginning, sampling was performed among 30 crusher operators at six quarries. Each operator was supplied with a pair of integrated sampling devices to create parallel comparisons between direct and indirect analysis methods. After completion of this phase, compliance monitoring was continued using the indirect method which showed better performance characteristic. A total of 70 crusher operators from nine quarries was sampled for compliance study. Exposure data between direct and indirect methods showed a good correlation (p < 0.01 r2 = 0.817) with no significant differences (p > 0.05). For the direct method, 37.9% of crusher operators were exposed to more than the permissible exposure limit (PEL) of RCS-quartz compared with 32.9% for the indirect method. The total coefficient of variance (CVT) for the direct method was reported at 14.86% while for the indirect method it was 14.52%. Overall the CVT value showed that the indirect method has slightly less variance or better accuracy as compared with the direct method. For direct method after considering the CVT, the percent of exposure result above the PEL was increased from 37.9% to 48.4%, while for indirect method, the value was increased from 32.3% to 43.1%. Based on performance characteristic on both methods, indirect was selected to be used for compliance study. Result from compliance study indicated that the mean percentage of RCS-quartz in silica dust was 22.5%. The estimated arithmetic mean (AM) for crusher operators' exposure was 0.426 mg/m3 for respirable dust and 0.091 mg/m3 for RCS-quartz. Around 30.5% of crusher operators were exposed to RCS-quartz levels above the PEL, but only 0.1% of them exposed to respirable dust above the PEL. Low exposure to respirable dust may conceal the need to justify comprehensive crystalline silica dust monitoring and lead to underestimation of RCS-quartz exposure. A high percentage of non-compliance exposure on personal RCS-quartz exposure should establish the need for quarry management to focus on better implementation of dust control., 'Certification of Master's/Doctoral Thesis' is not available,Ph.D.
Pages:	166
Call Number:	QP121.S854 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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