Acquired color vision impairment among gasoline station workers with occupational exposure of BTEX (case study in tehran city)

Color vision is one of the most important capabilities of the visual system. color vision impairment in many jobs, lead to reduced productivity, increased reaction time and workers' decision-making in confronting with of hazardous situations and as a result, it can lead to occupational accidents. This study was carried out to investigate occupational exposure to BTEX solvents and acquired color vision impairment among gasoline station workers in Tehran city.

This cross sectional study is conducted in the 15 gasoline station of Tehran city. The workers (680) were studied in three groups. The first group consisted of those working as a distributor of gasoline (289) with exposure to organic solvents. The second group included service workers (201) were working as a low exposure and third group was the administrative staff (190) that was considered as an no exposure to organic solvents. After recording the demographic characteristics of the participants in the standardized questionnaire and considering exclusion criteria, 193 from the first group, 132 from the second group and 114 from the third group were qualified to participate in the study. The visual acuity with the SnellenChart, inherent color vision impairment with Ishihara plates and Acquired color vision impairment with LANTHONY D-15 were determined. The determination of the concentrations of BTEX compounds was carried out according to the standard NIOSH 1501.

The frequency of acquired color vision impairment was 6.74% for workers distributor of gasoline, 1.51% for service workers, and 0% for administrative staff working at the same gas station. Color confusion index was higher in the first group than in the second group (p=.006). The results of logistic regression indicated there was a significant relationship between color confusion index (CCI) and exposure to BTEX compounds, age, work experience and smoking (p<.05).
Conclusion Based on the results of this study, the occupational chronic exposure of workers with BTEX compounds in gasoline station can lead to acquired color vision impairment in these people