The micronucleus assay in exfoliated buccal cells for occupational exposure studies: an overview

This review describes the use of the micronucleus (MN) assay with exfoliated cells from the oral mucosa in occupational studies. The molecular mechanisms leading to formation of MN (chromosomal breakage and aneuploidy) are well known. In total, 222 articles have been published since the method was developed in 1982. The majority of investigations were conducted with agricultural workers, followed by petrol station attendants, painters, pathology/anatomy lab workers, and miners. Positive results were reported in the majority of studies (86%); Brazil, Italy, Mexico, and Turkey being the most productive countries. The use of this technique increased substantially in recent years, and a recent correlation analysis with data from MN studies with lymphocytes indicates that the method is useful for predicting the cancer risks of chemically and radiation-exposed workers. The methodological quality of the studies increased in recent years since standardized and validated guidelines have been published. However, major shortcomings are still the lack of adequate matching (in particular in regard to nutrition and intake of dietary supplements), the lack of chemical exposure measurements, and the use of inadequate (DNA-nonspecific) stains. The most pronounced effects were seen in metal production workers, miners, petrol station attendants, agricultural workers, and pathologists. The sampling of cells from the oral cavity is noninvasive and requires no cultivation under sterile conditions is required. The currently available data indicate that this fast and easy-to-perform procedure provides valuable information about combined effects of chemical exposures and about the efficiency of safety measurements. Therefore, it should be used in the future for the routine surveillance of workers.