Avaliação da exposição ocupacional ao benzeno em trabalhadores frentistas e analistas de combustíveis utilizando o Teste Cometa como biomarcador de genotoxicidade

Gasoline-station workers in Brazil: Benzene exposure; Genotoxic and immunotoxic effects

Chronic exposure to benzene is a risk factor for hematological malignancies. Gasoline-station workers are exposed to benzene in gasoline, via both inhalation and dermal contact (attendants and managers) or inhalation (workers in the on-site convenience stores and offices). We have studied the exposure of these workers to benzene and the resulting genotoxic and immunotoxic effects. Levels of urinary trans, trans-muconic acid were higher among gasoline-station workers than among office workers with no known exposure to benzene (comparison group). Among the exposed workers, we observed statistically significant biological effects, including elevated DNA damage (comet assay); higher frequencies of micronuclei and nuclear buds (CBMN assay); lower levels of T-helper lymphocytes and naive Th lymphocytes; lower CD4 / CD8 ratio; and higher levels of NK cells and memory Th lymphocytes. Both groups of exposed workers (inhalation and inhalation + dermal routes) showed similar genotoxic and immunotoxic effects.

Analysis of Benzene Exposure in Gas Station Workers Using Trans,Trans-Muconic Acid

In Brazil, gas station workers are occupationally exposed to the benzene present in gasoline. Brazilian law indicates the use of trans,trans-muconic acid(t,t-MA) as a biomarker of benzene exposure. The aim of this study was to evaluate the level of exposure to benzene in gas station workers, through the quantification of t,t-MA present in urine. A total number of 269 gas station workers divided into 179 filling station attendants exposed by inhalation and dermal route and 90 convenience store workers exposed only by inhalation were included. A control group was formed by 100 office workers, without occupational exposure to benzene. The urinary levels of t,t-MA were evaluated by HPLC with a UV detector. Gas station workers showed higher mean values of t,t-MA (0.204 mg/g creatinine; 95% CI 0.170–0.237) than office workers (0.126 mg/g creatinine; 95% CI 0.0817–0.1693). T,t-MA levels were higher in convenience store workers exposed to gasoline only by inhalation (0.221 mg/g creatinine; 95% CI 0.160–0.282), than in those exposed to gasoline by inhalation and dermal route—filling station attendants (0.195 mg/g creatinine; 95% CI 0.155–0.235). Gas station workers with a higher level of t,t-MA had epistaxis. T,t-MA values were higher in the Downtown (0.15 mg/g creatinine) region’s workers than in the more affluent South Zone region’s workers (0.07 mg/g creatinine). Smoking habits influenced the urinary t,t-MA values, while the frequency of consumption of industrialized and frozen foods showed no influence.