Biomarkers of formaldehyde exposure for health surveillance

Background: This study aimed to identify suitable biomarkers of formaldehyde exposure to conduct health surveillance among embalmers. Micronucleus frequency, DNA damage, and genetic polymorphisms were studied. Methods: Ninety-eight staff in 13 hospitals were recruited and categorized into high or low formaldehyde exposure groups (n=49 for each group). For each participant, personal air sampling was taken and analyzed using the NIOSH method 2016. On the same day of air sampling, participants’ buccal tissue was collected and analyzed for micronucleus frequency by staining, DNA damage using the Comet assay, and polymorphism of Glutathione S-Transferase Pi 1 (GSTP1) by polymerase chain reaction methods. The average formaldehyde exposure concentration of the high-exposure group was 0.211 ± 0.482 ppm, which was higher than that of the low-exposure group (0.016 ± 0.017 ppm.) (P < 0.05). Results: For DNA damage, the average of tail length and %tail DNA, of the high exposure group was higher than that of the low exposure group (p < 0.05). However, the micronucleus frequency and frequencies of GSTP1 (Ile105Val) polymorphisms among the 2 groups did not significantly differ. Furthermore, among these 3 biomarkers, only DNA damage was associated with formaldehyde exposure (P <0.05). Conclusions: Based on these findings, assessing DNA damage using Comet assay is recommended as a biomarker of occupational exposure to formaldehyde and health surveillance. Key words: Embalmers, Formaldehyde, Micronucleus, DNA Damage, GSTP1 gene polymorphism