Color vision and occupational toluene exposure

Area of Science:

• Occupational Health
• Toxicology
• Neuroscience

Background:

• Solvent exposure in industrial settings is a concern for worker health.
• Toluene and total hydrocarbons are common industrial solvents with potential neurotoxic effects.
• Acquired color vision loss can be an early indicator of neurotoxicity.

Purpose of the Study:

• To investigate the association between occupational exposure to toluene and total hydrocarbons and acquired color vision loss.
• To determine if cumulative exposure indices correlate with color vision impairment.
• To assess the utility of the Lanthony D-15 desaturated panel in detecting early neurotoxic effects.

Main Methods:

• A cross-sectional study involving 125 male workers from printing and bookbinding plants.
• Exposure assessment included current airborne toluene levels and cumulative exposure indices for toluene and total hydrocarbons over 30 years.
• Color vision was evaluated using the Lanthony D-15 desaturated panel, with color vision loss quantified by the Color Confusion Index (CCI).

Main Results:

• Color Confusion Index (CCI) showed a positive correlation with current airborne toluene levels and cumulative exposure indices for toluene and total hydrocarbons (r values ranging from .18 to .35).
• Significant odds ratios for acquired dyschromatopsia were observed for current airborne toluene, past toluene exposure, and past total hydrocarbon exposure.
• Airborne toluene levels were generally below the Threshold Limit Value (TLV) of 50 ppm.

Conclusions:

• Occupational exposure to toluene and total hydrocarbons is associated with acquired color vision loss.
• The Lanthony D-15 desaturated panel can detect early neurotoxic effects in workers exposed to toluene.
• This study highlights the importance of monitoring color vision in workers exposed to solvents.