Effects Of Toluene Exposure On Color Vision In Informal Shoe Industry Workers

1. Emil F Sjahreza¹
2. Muhammad Sidik¹
3. Iwan Ariawan²

¹Department of Ophthalmology, Faculty of Medicine, University of Indonesia
²Faculty of Public Health, University of Indonesia

Purpose: To determine the proportion of dyschromatopsia among informal shoe industry workers, and the relationship between levels of toluene exposure from glue substance used in the industry and the severity of dyschromatopsia.

Method: Eighty eight subjects were submitted in this study, divided into high (direct) and low (indirect) exposure groups. Color discrimination function was assessed using the Lanthony desaturated D15 test. Dyschromatopsia was divided into protanomaly, deutanomaly, tritanomaly, and diffuse. The severity of dyschromatopsia was measured using Color Confusion Index (CCI) by means of Bowman scoring method. Toluene exposure was recorded based on ambient air concentration (part per million) and cumulative dose (ppm x work duration).

Result: 61.4% (27/44) subjects of the high exposure group and 22.7% (10/44) subjects of the low exposure group were confirmed to have dyschromatopsia (p<0.001). The most frequent type was diffuse, followed by tritanomaly, protanomaly, and deutanomaly. High exposure group showed significantly higher CCI compared to low exposure group (1,52 vs 1,17). High exposure group showed significantly higher values in both mean ambient toluene levels (23.92 ppm vs 4.14 ppm) and cumulative dose (2111.27 vs 486.46).
The proportion and severity of dyschromatopsia were found to be in significant correlation with the increment of both ambient concentration and cumulative dose.

Conclusion: Exposure to toluene in informal shoe factory workers is associated with impairment in color vision. Workers directly exposed to toluene have a higher risk of acquiring dyschromatopsia compared to those who are not. The risk and severity of dyschromatopsia increase with increasing exposure.