American Journal of Public Health Research
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American Journal of Public Health Research. 2018, 6(2), 44-50
DOI: 10.12691/ajphr-6-2-4
Open AccessSpecial Issue

Determinants of Respirable Crystalline Silica Exposure among Sand-stone Workers

Kanala Chanvirat1, Naesinee Chaiear1, and Thitiworn Choosong2

1Division of Occupational Medicine, Department of Community Medicine, Faculty of Medicine, Khon Kaen University, Thailand

2Department of Family Medicine and Preventive Medicine, Songkla University, Thailand

Pub. Date: March 22, 2018

Cite this paper:
Kanala Chanvirat, Naesinee Chaiear and Thitiworn Choosong. Determinants of Respirable Crystalline Silica Exposure among Sand-stone Workers. American Journal of Public Health Research. 2018; 6(2):44-50. doi: 10.12691/ajphr-6-2-4


Objective: Our aim was to determine the occupational exposure level for respirable crystalline silica (RCS) and respirable dust (RD) among sandstone workers. Materials and methods: This study was a descriptive analysis of the occupational exposure to respirable crystalline silica (RCS) and respirable dust (RD), utilizing personal air sampling from the breathing zone. The samples were collected throughout the 8-h working day: 88 samples were collected from workers performing stone cutting in mines and at home (wetting system), as well as stone chiseling and stone carving (22 samples each). Twenty-two samples were collected of the RD using the Gravimetric method (NIOSH 600), while for occupational exposure, the level of RCS was measured using a NIOSH7601 spectrophotometer. Results: Sand-stone workers had a geometric mean occupational exposure to RD of GM 1.84 mg/m3. The highest respiratory dust (RD) concentration (2.83 mg/m3) was found among the stone carvers. Those cutting stone at the mines had the next highest GM (2.65 mg/m3), while the lowest occupational exposure was seen among those chiseling stone(GM 0.9 mg/m3). The occupational exposure to RCS had a geometric mean of 0.10 mg/m3. The highest exposure group was for those cutting stone in the mines (GM = 0.14 mg/m3) followed by those carving stone (GM = 0.10 mg/m3). The moderate exposure group was for those chiseling stone (GM 0.05 mg/m3 ) followed by those cutting stone at home (GM = 0.03 mg/m3). The low exposure group had a GM of 0.03 mg/m3 for RCS. We found the quartz silica concentrations of the sandstone used in this area high (≤90%) as was the percentage of quartz silica in the airborne particulates for stone carving (≤71.4% by volume). Conclusion: The stone cutting in mines group and the stone carving group reached occupational exposure limits to RCS which exceeded the 0.05 mg/m3 OSHA PEL. It is essential to prevent such high exposure through engineering controls, by adapting tools and implementing medical surveillance. All groups had a RCS occupational exposure which would warrant medical surveillance as each group exceeded the OSHA action level of 0.0025 mg/m3.

silica respirable crystalline silica respirable dust pneumoconiosis sand stone

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