Mineral dust and cell recovery from the bronchoalveolar lavage of healthy Vermont granite workers.

We characterized the bronchoalveolar lavage (BAL) from healthy Vermont granite workers to investigate the pulmonary response to a chronic exposure to an injurious agent. Nine granite workers with 4 to 36 yr of employment in the industry and 27 unexposed volunteers were normal by history, physical examination, electrocardiogram, blood count, spirometry, and chest radiograph. Lavage cell recovery and percent neutrophils were not different. Lymphocyte recovery in BAL was increased in the granite-exposed population. Granite dust was present within the majority of alveolar macrophages from granite workers compared with those from control subjects, as determined by polarizing light microscopy and confirmed by scanning electron microscopy with X-ray energy spectrometry. There were no differences in phagocytic function or viability of macrophages from granite workers compared with those from unexposed volunteers. We conclude that in exposed populations, granite dust can be detected and semiquantitated in lavage specimens within the alveolar macrophages, macrophage function is preserved, and the response to this exposure involves an influx of lymphocytes.