Induction of micronuclei in human lymphocytes after occupational exposure to ultrasound

Micronucleus assay combined with Giemsa and DAPI staining was performed on blood samples of subjects occupationally exposed to ultrasound. Lymphocytes were cultivated in vitro for 72 h. At 44h cytochalasin-B was added in cult ures. Frequencies of micronuclei in exposed subjects statistically signific ant increased compared to control. The frequency of micronucleated cells an d micronuclei in exposed subjects shows interindividual variability. Using DAPI staining we observed signal-positive and signal-negative micronuclei. Percentage of signal-positive micronuclei varies between 0 and 66.7% and si gnal-negative micronuclei between 33.3% and 100%. This study indicate harmf ul effects of ultrasound on human genome, but further investigations are ne cessary. (C) 1999 Elsevier Science Ltd. All rights reserved.