Micronuclei in human alveolar macrophages.

Occurrence of micronuclei was monitored in pulmonary alveolar macrophages collected from 31 individuals undergoing diagnostic bronchoalveolar lavage. The overall frequency of micronucleated cells was 3.88 +/- 1.84/1000, without any significant difference attributable to sex, age, pathology, occupation, or smoking habits. The lack of influence of cigarette smoke on this clastogenicity index presumably reflects the very low rate of mitoses of macrophages in the alveolar lumen.