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Control technology and exposure assessment for occupational exposure to crystalline silica: report of 32 case studies.
Echt-A; Gressel-M; Almaguer-D
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :49
A major study to evaluate respirable crystalline silica exposures and document associated engineering controls was conducted in support of OSHA rule-making by NIOSH. This study examined 32 sites in a variety of manufacturing and construction settings. Personal air and bulk samples were collected in accordance with NIOSH Methods 0600 and 7500. At each site, information pertinent to process operation and control effectiveness (control methods, ventilation rates, work practices, use of personal protective equipment, etc.) was collected. The summary of engineering control information included such items as ventilation flow rates and distance measurements. The proximity of the control systems to open doors or windows, general ventilation intakes and exhausts, and other interacting equipment (i.e., pedestal fans) were also noted. The age and history of the control systems, cost of control installation, maintenance practices, and operation and maintenance costs were determined from facility management, when possible. Historical sampling data were also collected when possible (i.e., sampling data from before and after a control was installed). Crystalline silica is present in a variety of workplaces, encompassing construction, maritime and industrial settings. Silica may be present as a raw material (i.e., brick and plate glass manufacturing), as a processing material (i.e., foundries), or as a naturally occurring mineral in the workplace (i.e., tunnel construction, rock drilling, and excavation). As such, worker silica exposures are controlled to widely varying degrees, using widely varying methods. In this study, 30% (224/740) personal breathing zone samples exceeded the NIOSH REL of 0.05 mg/m3 , and 20% (147/740) exceeded their calculated OSHA PEL. Construction represented the highest exposures. In thirteen construction sites in this study, 66 of 152 (43%) samples exceeded the REL, while 54 (36%) of the samples were in excess of the PEL. In five foundries, 32% (90/281) and 22% (62/281) samples exceeded the REL and PEL, respectively.
Quartz-dust; Dusts; Dust-particles; Silicosis; Hazards; Workers; Work-environment; Work-areas; Personal-protective-equipment; Personal-protection; Respirable-dust; Respiration; Respiratory-protective-equipment; Respiratory-system-disorders; Respiratory-irritants; Dust-sampling; Engineering-controls; Construction; Air-sampling; Ventilation; Exhaust-systems
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana