Impairment of Neurobehavioral Function and Color Vision Loss among Workers Exposed to Low Concentration of Styrene. A Review of Literatures.

Abstract

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).

Occupational styrene exposure, colour vision and contrast sensitivity: a cohort study with repeated measurements

“…They have been summarised in reviews (Lomax et al 2004;Kishi et al 2000) and meta-analyses (Paramei et al 2004;Benignus et al 2005). The most extensive review covers thirteen studies (Lomax et al 2004).…”

Pilot Study on Prevalence of Color Vision Dysfunction in Long-Term Solvent-Exposed Painters.

“…In recent years, several studies concerning slight dyschromatopsia and color vision deficiencies in workers exposed to organic solvents have been published [1][2][3] . Only a few studies, however, focused on mixtures of organic solvents 4,5) .…”

Neurobehavioral science in hazard identification and risk assessment of neurotoxic agents—what are the requirements for further development?

“…Various industrial metals and solvents can affect vision, hearing and olfactory function, and some observations are also available for touch and taste functions. Receptors and nerve fibers may be the target of chemicals toxic to sensory perception, and whereas one substance can cause changes in different organs (for instance, styrene affects smell, hearing and vision in exposed workers), workers can also be exposed to different chemicals, with various interactions on sensory endpoints (Kishi et al 2000;Gong et al 2003). This is a promising and important area that definitely deserves further research on the mechanisms involved (Gobba 2003).…”