Monitoring of genotoxicity of formaldehyde on human buccal cells with comet assay

Purpose: Whether formaldehyde induces DNA breakage or not is still in debate. So far it is not clear whether dose-effect between formaldehyde and DNA breakage takes place while the DPC exists. Approach: In this study we had chosen human buccal cells as materials to explore the genotoxicity of liquid and gaseous formaldehyde with comet assay. Findings: The results showed that liquid formaldehyde induced DNA breakage in the range from 5 mu M to 10 mu M (P<0.05, compared with control group), and 7.5 mu M was found to induce DNA breakage most. The DNA crosslinks were significantly found at 15 mu M, 30 mu M and 50 mu M (P<0.01, compared with 7.5 mu M group). DNA breakage caused by gaseous formaldehyde was found at 0.5 mg/m(3) and 1.0 mg/m(3) (P<0.01, compared with control group) but DNA crosslinks; at 3.0 mg/m(3) Significantly. Conclusions: The results suggest that formaldehyde induces DNA breakage in a very low concentration range but induces DNA crosslinks in a higher range.