Comet assay based DNA evaluation of fuel filling stations and automobile workshops workers from Khyber Pakhtunkhwa province, Pakistan

Abstract

BackgroundFuel filling stations workers and automobile workshops mechanics are consistently exposed to gasoline hydrocarbons during their occupation, this may cause DNA damage. Objective of this study was to evaluate the level of DNA damage in subjects occupationally exposed to these hydrocarbons.MethodsComet assay was performed on blood lymphocytes of exposed subjects to assess the probable DNA damage. 100 cells per individual were scored and graded by comet tail length. Exposed group consisted of 98 subjects (age 25.4 ± 7.2 years), of which 68 were CNG/Petrol filling men and 30 were automobile workshop workers, selected randomly from different service stations and automobile workshops of populated and adjacent cities of Peshawar, Mardan and Nowshera of Khyber Pakhtunkhwa province, while control group included 92 subjects (age 26.7 ± 11.8 years) were also from the same areas.ResultsSignificantly high level of DNA damage was found in the subjects exposed to gasoline hydrocarbons as compared to control subjects (173.2 ± 50.1 and 61.0 ± 25.0, P = 0.001, respectively). Period of exposure and use of tobacco also showed considerable effects (P < 0.05) on DNA damage, while effect of age and daily working hours on total comet score (TCS) were non-significant (P > 0.05).ConclusionsThe results of our study concluded that petroleum hydrocarbons have the potential to cause DNA damage in the exposed subjects. The study also suggested that protective strategies should be implemented by the concerned authorities to minimize exposure to fuel hydrocarbons.

Genotoxic effects of occupational exposure to benzene in gasoline station workers

“…On the other hand, an increase in total comet score with an increase in exposure duration was described in a study recruited in Pakistan 1 ) . Also, a close relationship between workers’ genotoxicity and duration of occupation was found in Canadian petroleum stations 34 ) .…”

“…Occupational exposure to chemical hazards and toxic substances can cause a variety of health hazards ranged from irritation to carcinogenicity. Gasoline station workers who are a part of fueling and refueling of vehicles are at higher risk of adverse health effects 1 ) . Gasoline station workers are exposed to volatile organic compounds such as ƅenzene, toluene, ethyl ƅenzene and xylene (BTEX) from fuel vapors during dispensing fuel, in addition to emissions from vehicle exhausts.…”

The Effects of Benzene on Micronuclei Frequency of Workers in Petrol Stations in Duhok- Iraq

“…Petrol stations are a commonplace where workers, who are a part of fuelling and refueling of vehicles, are at higher risk of health effects. 13 Petrol station workers are regularly exposed to volatile organic compounds such as toluene, benzene, ethylbenzene and xylene from fuel vapors during dispensing fuel, in addition to emissions from vehicle exhausts. They are directly exposed to these chemical compounds through inhalation and direct dermal contacts.…”

Evaluation of DNA Damage in Patients with a Neuroendocrine Tumor

“…Staining and scoring for DNA damage: 50 µL of EtBr (2 µg/mL) was added to each slide. The slides were covered with a coverslip and immediately analyzed using a fluorescence microscope (Nikon) (15,17). The DNA damage was calculated by taking images of 100 randomly selected cells at 400× magnification using a fluorescent microscope and analyzed visually according to comet appearance (15,17).…”

“…Each image was classified according to the intensity of the fluorescence in the comet tail and was provided a value of 0, 1, 2, 3, or 4 (from undamaged class 0 to maximally damaged class 4) (15,17). The total comet score was calculated using the formula: (total comet score=0 (n)+1 (n)+2 (n)+3 (n)+4 (n), where n represents the number of cells in each class (17)(18)(19). The slides were analyzed under blind conditions by at least two different individuals.…”