METHODS: The OSHA investigation consisted of industrial hygiene sampling, a review of medical records, and case interviews.
RESULTS: Some personal sampling measurements exceeded the OSHA Permissible Exposure Limit (PEL) for total dust exposures of 15 mg/m(3), and the measured respirable silica exposure of 0.043 mg/m(3), although below OSHA\'s current PEL for respirable dust containing silica, was above the American Conference of Governmental Industrial Hygienists\' Threshold Limit Value (TLV). Chest x-rays for all four workers identified small opacities consistent with pneumoconiosis.
CONCLUSIONS: This is the first known report of lung disease in workers processing coal slag and raises concerns for workers exposed to coal slag dust.