Home/Comet assay news/Exposure to formaldehyde

Exposure to formaldehyde

Formaldehyde is a global high-production compound with numerous applications ranging from production of resins to medicines. Due to its sensitizing properties, irritating effects and potential cancer hazard, formaldehyde is of great environmental health concern. Previously, formaldehyde-induced genotoxicity has been confirmed in a variety of experimental systems, ranging from bacteria to rodents.

Researchers based at the National Institute of Health in Porto, Portugal and their collaborators have been investigating occupational exposure to formaldehyde. In order to assess the genotoxic effects of chronic occupational exposure to formaldehyde, a group of pathology/anatomy workers were assessed using the micronucleus test and comet assay.

The highest level of human exposure to formaldehyde occurs in occupational settings. Occupational exposure involves not only individuals employed in the direct manufacture of formaldehyde and products containing this chemical, but also those subjects using these products, namely, in pathology and anatomy laboratories where formaldehyde is commonly used as a fixative and tissue preservative. For the environmental exposure assessment, air sampling was performed in worker’s breathing zone for representative working periods, and an 8 hour time-weighted average was determined. A control group were also assessed for comparison.

The alkaline version of the comet assay was performed and two slides were prepared for each donor. A “blind” scorer examined 50 randomly selected cells from each slide (100 cells/donor) using a magnification of x40. Image capture and analysis was performed with Comet Assay IV from Perceptive Instruments. Both per cent tail DNA and tail length were determined.

The researchers found that the comet assay parameters were significantly higher in exposed subjects when compared to the control subjects. It was concluded that for formaldehyde exposure assessment, the micronucleus test and comet assay are useful biomarkers in the evaluation of genotoxic effects in human populations occupationally exposed to this aldehyde.

The results from this investigation, along with recent implications of human carcinogenicity, lead the researchers to conclude that there is a need for close monitoring of occupational exposure to formaldehyde. Implementation of security and hygiene measures, as well as good practices campaigns, may be crucial to decrease risk.

Case study based upon:

Genotoxic Risk Evaluation By Comet Assay And Micronucleus Test Using Human Peripheral Lymphocytes Costa S, Pina C, Coelho P, Costa C, Silva S, Porto B, Laffon B, Teixeira JP.
J Toxicol Environ Health A. 2011;74(15-16):1040-51