Impairment of colour vision in workers exposed to organic solvents

Objectives-To investigate loss of colour vision related to exposure to solv ents and the role of three enzyme polymorphisms in modifying the risk in ex posed workers. Methods-A sample was studied of 68 male dockyard workers and 42 male commun ity controls with and without neuropsychological symptoms from a previous c ross sectional study. Indices of cumulative and intensity based exposure to solvents were calculated for all subjects. Alcohol, drug, and smoking hist ories were obtained. Colour vision was tested by Lanthony D15d colour visio n test. Genotype of glutathione S-transferase M1 and T1 and N-acetyltransfe rase 2 polymorphisms were determined. Results-The relation between impairment of colour vision and exposure to so lvents was investigated with multiple regression techniques. Increasing ann ual exposure to solvents was significantly associated with reduced colour v ision (p=0.029). Impairment of colour vision was not associated with neurop sychological symptoms as measured by the Q16 solvent symptom questionnaire. No significant association was found between acquired impairment of colour vision and genetic polymorphisms when GSTM1, GSTT1 or NAT2 phenotypes were included in the analyses. Conclusions-Exposure to mixed solvents is associated with impairment in col our vision, the risk increases with increasing exposure. The risk of impair ment of colour vision was not altered in this study by the presence of diff erent GSTM1, GSTT1 or NAT2 polymorphisms.