EVALUATION OF THE RISK OF OXIDATIVE STRESS IN NON-PETROL STATION DISPENSERS OF GASOLINE IN GOMBE, NIGERIA

Abstract

BACKGROUND
Occupational exposure to toxic chemicals such as gasoline is a major Public Health concern
worldwide. Gasoline is one of the most frequently utilized chemicals whose use is on the
increase. When absorbed, the volatile constituents of gasoline generate free radicals leading to
oxidative stress. This is associated with nucleic acid, lipids and proteins damages leading to
chronic diseases including cancers.

SUBJECTS AND METHODS
Markers of oxidative stress including plasma levels of total anti oxidant status (TAS), antioxidant
vitamins (A, C and E), antioxidant trace metals (zinc, manganese, copper, selenium), lead,
cadmium and uric acid were compared between 90 road side dispensers of gasoline and 90 age
and sex matched controls. Urea and creatinine were also compared between the two groups.
Vitamins A, C and E assays were performed using an Ultra sensitive and specific HPLC. Plasma
zinc, selenium, manganese, copper, lead and cadmium ware analysed using Atomic Absorption
Spectrophotometer (AAS). Total anti oxidant status, uric acid, urea and creatinine were
measured using standard colourimetric methods.
RESULTS
The mean age of the exposed and control groups are 29.03 ± 3.7 and 29.24 ± 3.5 years
respectively. The mean plasma levels of TAS (0.60 ± 0.33 mmol/L), vitamins A (54.45 ± 6.4
µg/dl), vitamin C (0.68 ± 0.13µg/dl) and vitamin E (0.72 ± 0.10 µg/dl), antioxidant trace metals
zinc (64.7 ± 6.09µg/dl), manganese (7.93 ± 1.32 µg/dl) and copper (77.8 ± 7.38 µg/dl) of the

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exposed were significantly (p< 0.001) lower than the controls (1.29 ± 0.25mmol/L, 69.82 ±
5.4µg/dl, 1.06 ± 0.13µg/dl, 1.01± 0.13µg/dl, 100.2 ± 9.58µg/dl, 9.22 ± 1.19µg/dl and 103.8 ±
20.09 µg/dl respectively). The mean plasma uric acid (5.35 ± 0.9mg/dl), selenium (0.03 ± 0.008
µg/dl), lead (0.02 ± 0.0054 µg/dl) and admium (0.02 ± 0.0045 µg/dl) were significantly (p<
0.001) higher in the road side dispensers of gasoline compared to the controls (4.48 ± 0.9 mg/dl,
0.01 ± 0.0023 µg/dl, 0.01 ± 0.0024 µg/dl and 0.01 ± 0.002 µg/dl respectively). There was no
significant difference in the plasma level of urea and creatinine between the two groups.
CONCLUSION
The data has demonstrated higher level of oxidative stress in road side dispensers of gasoline
compared to the controls. This is an indication that road side gasoline dispensers are probably at
greater risk of developing chronic diseases associated with increase oxidative stress. Antioxidant
supplementation may be of benefit to the road side gasoline dispensers. Legislation on road side
gasoline dispensing should be enforced to reduce the incidence of long term complications from
exposure.