Engineering Controls for Selected Silica and Dust Exposures in the Construction Industry -- A Review

Abstract

This literature review summarizes engineering control technology research for dust and silica exposures associated with selected tasks in the construction industry. Exposure to crystalline silica can cause silicosis and lung fibrosis, and evidence now links it with lung cancer. Of over 30 references identified and reviewed, 16 were particularly significant in providing data and analyses capable of documenting the efficacy of various engineering controls. These reports include information on generation rates and worker exposures to silica and dust during four different tasks: cutting brick and concrete block, grinding mortar from between bricks, drilling, and grinding concrete surfaces. The major controls are wet methods and local exhaust ventilation. The studies suggest that while the methods provide substantial exposure reductions, they may not reduce levels below the current ACGIH threshold limit value (TLV) of 0.05 mg/m(3) for respirable quartz. Although further research on controls for these operations is indicated, it is clear that effective methods exist for significant exposure reduction.

Environmental, Inhaled and Ingested Causes of Pulmonary Fibrosis

“…The incidence of silicosis is decreasing due to better industrial hygiene measures in mining (De Vuyst and Camus, 2000). Despite these efforts silicosis is still seen because silicosis may occur with sand blasting, processing of scouring powders, silica flour or use of diatomaceous earth (De Vuyst and Camus, 2000;Flynn and Susi, 2003). Silicosis may also occur in dental technicians, who use grinding material with silica (De Vuyst and Camus, 2000).…”

“…Silicosis occurs by inhalation of crystalline silica as quartz, cristobalite, or trydimite (De Vuyst and Camus, 2000) found in sand blasting, drilling, pulverizing, cutting bricks and concrete blocks, grinding concrete, and other pneumatic equipment (Flynn and Susi, 2003). Exposure to silica results in a number of disease (Table 3), but of these conditions, chronic silicosis is a fibrotic lung disease.…”

“….− 2 that can lead to lung injury by peroxidation (Flynn and Susi, 2003). The ROI can induce NF-κB, a transcription factor whose gene products are inflammatory and fibrotic in nature (Flynn and Susi, 2003).…”

“…Exposure to silica results in a number of disease (Table 3), but of these conditions, chronic silicosis is a fibrotic lung disease. Chronic silicosis is the most common disease caused by silica exposure and occurs after approximately 10 years of exposure with dust content of 18-30% of crystalline silica (Flynn and Susi, 2003).…”

Quartz Measurement in Coal Dust with High-Flow Rate Samplers: Laboratory Study

“…In many occupational environments, engineering controls such as wet methods and local exhaust ventilation do provide substantial exposure reductions of respirable crystalline silica (Flynn and Susi, 2003;Akbar-Khanzadeh et al, 2007). Consequently, the silica mass on a typical air sample is reduced and often close to the detection limit.…”