Nasal mucosa micronuclei as early biomarkers of effect in workers exposed to airborne pollutants: a literature overview

Occupational exposure to air pollutants poses a serious health concern for workers, particularly due to potential genotoxic effects. The micronucleus (MN) test is widely recognized as a reliable biomarker of early genetic damage. Although commonly applied to lymphocytes or buccal epithelial cells, the nasal mucosa, being the first site of contact for inhaled toxicants, has received relatively limited attention. This review aims to evaluate the scientific literature on the use of MN in exfoliated nasal epithelial cells as a biomarker of early genotoxic effects in workers exposed to air pollutants. We conducted a comprehensive literature search using PubMed and gray literature sources. Seventeen studies were identified that examined the frequency of MN in nasal cells of exposed workers, with or without comparison with other biomarkers, such as buccal or blood cells. Most studies have reported a significant increase in MN frequency in nasal cells following exposure to substances, such as FA, heavy metals, wood dust, and industrial chemicals. In some cases, nasal MNs appeared more sensitive than other cellular targets. However, data heterogeneity, lack of standardized protocols, and limited control for confounding factors (e.g., smoking, diet) hinder in-depth comparisons and meta-analyses. Nasal MN testing offers a promising, non-invasive tool for biomonitoring genotoxic exposure in occupational settings. However, further research is needed to develop standardized protocols, control for confounding factors, and clarify the relationship between MN frequency, exposure characteristics, and other biomarkers of effect.