Impairment of neurobehavioral function and color vision loss among workers exposed to low concentration of styrene--a review of literatures.

Recently many studies on the health effects of workers who exposed to low-concentration styrene have been published. In this paper firstly we mentioned the reasons why nervous system was critical organ for evaluating the toxicity of organic solvents both in the acute and chronic exposure phases. Then we indicated how neurobehavioral test batteries were useful to detect subclinical adverse health effects of workers exposed to organic solvents. Secondly we reviewed many epidemiological studies on the impairment of neurobehavioral function, i.e., perceptual speed, memory, cognition, personality and mood, and the loss of color vision among styrene workers. Finally, we showed our recent data on the relationship between color vision loss and the concentration of urine metabolites among styrene workers. It can conclude that styrene may cause damage on nervous system, even at the low exposure level such as 50 ppm which used to be the Threshold Limit Value (TLV) recommended by Japan Society for Occupational Health (until 1999) and American Conference of Industrial Hygienists (until 1997).