Induced cytotoxic damage by exposure to gasoline vapors: a study in Sinaloa, Mexico

Is micronucleus assay in oral cells suitable biomarker for evaluating the risk of carcinogenesis in gas station attendants? A systematic review

This study aimed to evaluate all studies which used the micronucleus assay using oral cells in the attempt to understand whether such technique is efficient in evaluating genotoxicity in gas station attendants. Full manuscripts from 16 studies were carefully selected by the authors. Our results demonstrate that continuous exposure to derivatives of petroleum may lead to genotoxic effects since all studies demonstrated positive findings (16 out of 16) and 11 of them had a strong or moderate final rating. In summary, our results reveal that gas station attendants are occupationally exposed to genotoxic agents and that the micronucleus assay in oral mucosa is indeed an effective method to evaluate genotoxicity in this specific case. Such findings are very important for protecting these professionals who are continuously exposed to chemicals for long periods.

Induced sputum abnormalities in gas station attendants

PURPOSE

To investigate inflammatory changes in the induced sputum (IS) of gas station attendants (GSAs) at risk of exposure to fuel vapors through inhalation and susceptible to respiratory complaints and impaired lung function.

METHODS

Hypertonic saline-IS was collected from 52 GSAs who had never smoked (42 men, age = 35.9 ± 8.9 years) and had no known comorbidities. A group of 22 non-smokers (11 men, age = 30.5 ± 5.1 years) selected from the University staff served as control. The GSAs answered a questionnaire and underwent spirometry and chest tomography. A total of 15 inflammatory biomarkers associated with inflammation, including cytokines, chemokines, and mediators of immunological response, were also measured.

RESULTS

The most common symptoms of GSAs were coughing (42.3%) and dyspnea (59.6%) based on the New York Heart Association (NYHA; Class II) classification. Significant elevations (p < 0.05) in forced vital capacity and forced expiratory volume within the first second were observed in the GSAs relative to those in the controls (GSA vs. control: 99 ± 12% vs. 90 ± 9% and 94 ± 11% vs. 87 ± 10%, respectively). The GSAs had a lower percentage of IS lymphocytes than that in the control group (4.5 ± 5.7% vs. 7.7 ± 9.8%). The GSAs also had significantly lower concentrations of IL-4, IL-5, IL-10, IL-12_P70, IFN-γ, and MIP-1α, but IL-3 levels were higher. No differences were observed in the airway thickness and the amount of emphysema between the GSAs and the controls.

CONCLUSION

Despite normal lung function and absence of abnormalities on HRCT, GSAs have a higher frequency of respiratory complaints, with evidence of impairment of lymphocytic activity in the airways.

Nuclear abnormalities in umbilical cord blood lymphocytes of newborns from the Ahome and Guasave municipalities in Sinaloa, Mexico

AIM

We measured the frequency of nuclear abnormalities of 210 blood samples from the umbilical cord, since human fetuses are exposed to environmental mixtures of pesticides that induce DNA damage.

METHODS

The determinations were made through the micronucleus assay test in lymphocytes from the umbilical cord blood of newborns whose mothers live in Ahome (n = 105) and Guasave (n = 105), Sinaloa, Mexico.

RESULTS

The average frequency of anomalies in 1000 cells were, respectively: micronucleus 0.4 vs. 2.9, pyknotic cells 18.3 vs. 109.2, chromatin condensation 7.7 vs. 150.1, karyolitic cells 1.8 vs. 24.4, and binucleated cells 4.9 vs. 74.6. The calculated Pearson correlation factors of nuclear abnormality frequencies between both municipalities were low and negative, suggesting that they did not correlate between the Ahome and Guasave newborns and indicating a higher number of mothers exposed in Guasave.

CONCLUSION

Our data suggest that monitoring nuclear abnormalities in umbilical cord blood samples could be a useful tool to identify transplacental mutagens perfusion that is being discharged into the local environment.

Buccal micronucleus assay in human populations from Sicily (Italy) exposed to petrochemical industry pollutants

Petroleum refinery workers are potentially exposed to a wide range of petrochemical industry pollutants (PIP), such as benzene and 1,3-butadiene, cancer-related compounds classified as carcinogenic to humans. The aim of this study was to evaluate the cytogenetic effects of exposure to PIP from two industrialised areas in South/East Sicily (Italy) using a micronucleus (MN) assay and other nuclear anomalies (ONA) on exfoliated buccal cells. Results highlighted not only a statistically significant high level of increase of MN in petroleum refinery (PR) workers, but also in the subjects not working in PR but living in the industrialised area. The ONA analysis showed a highly significant increase in karyolytic cells in exposed vs unexposed subjects, in contrast to a decrease in differentiated cells. These results suggest the presence of a cytotoxic effect in the oral mucosa cells, probably related to the pollutant compounds present in the environment close to the petrochemical industries. Our data confirm that the analysis of exfoliated buccal cells is a useful and simple non-invasive method to evaluate the genotoxic/cytotoxic effects of pollutants in a specific area. To avoid confounding factors due to the different lifestyles of the human subjects, the above assays could be better applied on farm animals, which have a relatively consistent lifestyle and, in some cases, a very low genetic heterogeneity.