Assessment of Thyroid Function in Workers Occupationally Exposed to Gasoline and Paint Products in Anambra Central of Nigeria

Hydrocarbons (benzene, toluene, ethyl benzene and xylene (BTEX) found in gasoline and organic solvents are ubiquitous in the environment, and are known to have toxic effects in human system. This study therefore investigated the thyroid function of workers occupationally exposed to gasoline and paint products using TSH, T3 and T4 as markers. A total of 162 subjects were recruited for this study; (56 gasoline pump attendants and 56 paint factory workers) and 50 subjects as control. Blood sample was collected from each subject and thyroid function tests (T3, T4 and TSH), were assayed using Enzyme linked immunosorbent assay (ELISA) techniques. The mean values of TSH was significantly lower in the gasoline workers and painters compared to the control subjects (1.73±0.89, 1.66±0.84 Vs 2.09±1.06µIU/ml; F= 3.169, p<0.05). The mean values of T4 was significantly lower in gasoline workers and painters when compared to the control subjects (9.09±1.87, 9.63±1.90 Vs 12.06 ± 1.82µg/dl; F= 37.430, p<0.05). However, the mean levels of T3 was significantly higher in gasoline workers and painters compared to the control subjects (2.56± 0.65, 2.72 ± 0.65 Vs 1.03 ± 0.30ng/ml; F= 161.292, p<0.05). The mean body mass index, systolic and diastolic blood pressures were similar in all the groups. The levels of TSH showed a significant inverse correlation with the duration of exposure in the subjects exposed to gasoline (r=-0.326, p<0.05), whereas the levels of T3 showed a positive significant correlation with the duration of exposure in paint workers (r=0.301; p<0.05). This study demonstrated that both gasoline and paint showed similar effects on the thyroid parameters of the subjects under study, which is suggestive of T3 thyrotoxicosis.