An Occupational Risk Survey of a Refractory Brick Company in Ha Noi, Viet Nam

Abstract

Viet Nam has an increasing need for building materials, including refractory bricks. Little is known regarding the occupational hazards incurred in brick manufacturing. To determine the occupational health hazards posed by a refractory brick operation in Ha Noi, Viet Nam, a cross-sectional occupational risk survey was conducted, focusing on respirable dust hazards. It included an industrial hygiene walk-through and gravimetric dust analysis. Noise, heat, lack of head protection, and dust exposure were hazards identified at the brick-manufacturing site. Respiratory protection involved a three-layer cloth mask that had not been tested for efficacy. Silica dust exposure levels exceeded the Vietnamese permissible exposure level by almost fivefold based on gravimetric assessment and estimated silica content. This brick manufacturing site contains significant injury and respiratory illness hazards. Further investigations are necessary to begin to develop occupational safety measures at the site.

Pneumoconiosis among workers in a Vietnamese refractory brick facility

“…Hence the renovation to the ventilation system was made. Nonetheless, there is continued risk as evidenced by recent exposure assessment describe elsewhere [Hai et al, 2001] and our health findings in this survey. Unfortunately, no exposure assessment data exist from the period before renovations.…”

“…Exposure assessment data was gathered for some job titles [Hai et al, 2001]. For those job titles, gravimetric dust data are noted in Table I.…”

“…Attempts to correlate gravimetric dust analyses with health outcomes were likewise not useful despite results which demonstrated respirable silica dust levels 4.8 times NIOEH PEL (Vietnam regulations) and eight times OSHA PEL (US regulations) [Hai et al, 2001]. The exception was in the powder processors who had a high proportion of abnormal radiographs (15%) and the second highest dust level (8.7 mg/m 3 ).…”

“…The manufacturing process has been described in detail previously [Hai et al, 2001]. Rocks and kaolin clay are chopped, mixed, dried/burned, and then crushed.…”

“…Exposure assessment and further details of the occupational risk survey are described elsewhere [Hai et al, 2001]. Briefly, we found respirable silica dust exposure levels up to 4.8 times the permissible exposure levels (PEL) of the Vietnamese NIOEH standards (i.e., eight times US Occupational Safety and Health Administration PEL), as well as excessive noise, heat, and safety hazards.…”