Exposure to chemicals and particles generated in automotive repair shops is a common and underestimated problem. The objective of this study was to assess the genotoxic status of auto repair workers with (1) a questionnaire to gather sociodemographic information and self-reported exposure to hazardous chemicals and (2) measurement of various biochemical parameters. Blood and oral mucosa samples were collected from 174 male volunteers from Barranquilla, Colombia, aged 18-55 years: 87 were active car repairmen and 87 were individuals with no known exposure to hazardous chemicals. Peripheral blood lymphocytes were collected for the comet and cytokinesis-blocking micronucleus (CBMN) assays, while oral mucosal epithelium extracted to quantify micronucleated cells (MNC). DNA was extracted to assess polymorphisms in the DNA repair (XRCC1) and metabolism-related genes (GSTT1 and GSTM1) using PCR-RFLP. DNA damage and frequency of micronuclei (MN) in lymphocytes and oral mucosa were significantly higher in exposed compared to control group. In both groups genotypes and allelic variants for XRCC1 and GSTT1 met the Hardy-Weinberg equilibrium (HWE). In contrast, GSTM1 deviated from HWE. In the exposed group genotypic variants were not correlated with DNA damage or MN presence in cells. DNA damage and occurrence of MN in mucosa and lymphocytes correlated with age and time of service (occupational exposure ≥ 3 years). In summary, workers in car repair shops exhibited genotoxic effects depending upon exposure duration in the workplace which occurred independent of DNA repair XRCC1 gene and metabolism genes GSTT1 and GSTM1. Date demonstrate that health authorities improve air quality in auto repair facilities to avoid occupational DNA damage.
Keywords: Air pollutants; DNA damage; genotypes; micronuclei; polymorphisms; toxicity biomarkers.