Occupational Formaldehyde Exposure and Genotoxic Effects Among Pathology and Mortuary Workers in South East Nigeria

Formaldehyde is a confirmed human carcinogen widely used in pathology and mortuary settings for tissue fixation, with genotoxic effects increasingly documented at occupational exposure concentrations. This analytical study assessed occupational formaldehyde exposure levels and genotoxic biomarkers among pathology and mortuary workers in tertiary health institutions in South East Nigeria, specifically Enugu, Anambra, and Imo States. One hundred and twenty exposed workers and 60 unexposed administrative controls were recruited. Formaldehyde air concentrations were measured using validated passive diffusion sampling badges. Genotoxicity was assessed using the micronucleus assay in peripheral blood lymphocytes and the comet assay for DNA strand breaks. Mean formaldehyde concentrations in work zones exceeded the IARC recommended limit of 0.3 ppm in 71.7 percent of samples. Micronucleus frequency was significantly higher in exposed workers compared to controls (p less than 0.001), and comet tail moment values indicated significant DNA strand break elevation. Duration of formaldehyde exposure above eight years was the strongest predictor of elevated genotoxic markers. Protective respiratory equipment compliance was only 17.5 percent. This study provides the first multi-site genotoxicity data for formaldehyde-exposed pathology workers in South East Nigeria and recommends engineering controls to reduce formaldehyde air concentrations, biological genotoxicity surveillance programs, and substitution of high-concentration fixatives with less genotoxic alternatives. Keywords: formaldehyde exposure, genotoxicity, micronucleus assay, pathology workers, South East Nigeria.