Silica exposure during granite countertop fabrication.

Occupational exposure to crystalline silica has received renewed attention. The National Conference to Eliminate Silicosis in March 1997, was extensive. The conference included workshops that covered silica exposures and the risks in construction, the mining industry, quarries, and foundries.(1) The Occupational Safety and Health Administration (OSHA) launched a special emphasis program in May 1996, to inform employers and employees about the occurrence, hazards, and controls of crystalline silica.(2) Some state OSHA plans adopted the emphasis, including the state of Washington. It is well documented that chronic and, in some cases, acute exposure to dust containing silica can cause serious health problems.(3) Silicosis is an incurable lung disease resulting in death or disability. Smokers are at an increased risk; smoking and silica act synergistically in causing chronic obstructive disease in the lung.(4 ¡ 6) Silica exposure has also been associated with other lung diseases, such as tuberculosis(7 ¡ 8) and lung cancer.(9¡ 11) Washington state alone recorded 201 deaths from silicosis between 1968 and 1992.(12) The health consequences have been known for years for workers in mining and manufacturing.(13) It has been known for over 80 years that fabrication of granite produces silicosis.(14) A speciŽ c type of granite fabrication was the focus of a number of recent industrial hygiene surveys in the state of Washington reported in this case study. The authors representing theWashington State Department of Labor and Industries and the University of Washington’s Field Research and Consultation Group participated in a number of work site surveys of businesses fabricating granite products for commercial and residential structures. Workers were engaged in fabricating granite kitchen countertops, kitchen islands, tables, tiles, lathed banisters, andother customized stonepieces. Tasks that could generate visible and signiŽ cant airbornegranite dust include cutting, grinding, and Ž nishing. All shops surveyed were found to work with limestone, granite, or marble. Granite may be expected tomost consistently present the potential for exposure to silica. Crystalline silica is a common but variable component of granite. The percentage typically varies by color. The lighter colors contain greater percentages of crystalline silica or quartz (e.g., white ranges 25–45%). The darker granites typically contain less (e.g., black ranges 0–15%). This case study reports on levels of exposure to airborne crystalline silica and methods of dust control for several granite countertop businesses in the State of Washington. Exposures are likely in other regions of the country where these products are in demand. Though the literature contains reports of silica exposures for stonecutters and rock crushers,(15 ¡ 18) the authors were unable to Ž nd reports speciŽ c to the granite countertop industry. Granite countertop fabrication was observed to be an emerging small employer industry in the state of Washington. This case study is also an example of several public agencies targeting an occupational health hazard in a speciŽ c industry through research, information, consultation, and enforcement.