Student Research: Phoung Thi Nguyen

, Industrial Hygiene & Safety (IH&S) - No longer offered, 2004
Faculty Advisor: Michael G. Yost

Silica Exposure Assessment of Refractory Brick Workers in Vietnam


Rapid development in Vietnam is increasing the need for construction materials, particularly for refractory brick. Silica is a major component in refractory brick production; however, exposures to high levels of silica dust may cause silicosis and other lung diseases. This increased risk of silica exposure has prompted a need to more efficiently characterize the dust levels refractory brick workers encounter, thus avoiding misclassification in epidemiological studies, as well as to better understand ways to prevent disease.

Although provincial factory inspection records of dust levels in Vietnamese refractory brick plants have been collected and maintained, exposure information in these records were obtained using the Vietnamese sampling and analytical methods. Understanding the relationship between the Vietnamese method and the US National Institute for Occupational Safety and Health (NIOSH) methods will be useful in silica exposure assessment. If a methods-comparison shows that there is a stable relationship between the two methods, this will have many benefits. For example, Vietnamese researchers will be able to use existing Vietnamese inspection reports to conduct epidemiological studies as well as to compare their findings to published studies that use the NIOSH sampling and analytical method.

Therefore, the principle research objective of this study was to assess the silica dust exposures refractory brick workers encounter, as well as to determine the relationship between the Vietnamese sampling and analytical method and the NIOSH method. We worked with the Vietnamese National Institute of Occupational and Environmental Health (NIOEH), which uses both the Vietnamese and NIOSH methods, to characterize silica dust exposures at two refractory brick companies that had similar work processes and job titles. The dust samples taken using the Vietnamese sampling and analytical methods were compared to those taken using the NIOSH sampling and analytical methods in order to better understand the relationship between the two methods.

This study was also an opportunity to extend the work of Duan NH and Sanders KC in, An Occupational Risk Survey of a Refractory Brick Company in Hanoi, Vietnam. The factory and sampling areas chosen in our study was influenced by the Duan and Sanders study and was an extension of their work. This allowed us to see if there were any differences between our study and their study, thus provided additional insights into silica dust prevention.

Taken from the beginning of thesis.