Defective neutrophil function in workers occupationally exposed to lead.

Chemotaxis and nitroblue tetrazolium reduction were measured in peripheral blood neutrophils of workers occupationally exposed to lead. These two neutrophil functions were significantly reduced, as compared to controls, even in those workers with blood lead levels and urinary delta-aminolevulinic acid (ALA-U) concentrations below the currently accepted biological limit values of 60 micrograms/dl and 6 mg/l, respectively. The immunosuppressive effects of relatively low level lead absorption suggests that immune dysfunction may be a sensitive indicator of lead exposure.