title: Acquired dyschromatopsia among petrochemical industry workers exposed to benzene.
abstract: Exposure to organic solvents, which are widely used in industry, can lead to dysfunction of the nervous system. However, controversy continues about the nature of early-stage damage to the nervous system from low-grade chronic exposure to organic solvents. Since loss of color-vision can be a sensitive early marker of neurotoxic damage, the main aim of this study was to investigate the association between low-level chronic exposure to organic solvents, especially benzene, and acquired dyschromatopsia. The study initially comprised 1236 workers who were employed at a large petrochemical distillation factory. After excluding those workers who may have had color-vision impairment due to congenital or acquired eye diseases and those with other medical conditions, 908 males who had worked for at least 6 months were included in the final analysis. Those who worked only in the office were categorized as nonexposed, while those who worked at outside facilities were divided into three groups of approximately equal size according to their estimated cumulative exposure levels to benzene (low, medium, high). Color-vision was assessed using the Lanthony D-15 desaturated panel color test. The results showed that the color-confusion index (CCI) was positively related to age. In the qualitative assessment of types of color-vision loss, the prevalence of total dyschromatopsia was significantly higher with increasing cumulative exposure levels in the left eye (p<0.05) but not in the right eye. The significance for the prevalence of type III dyschromatopsia was borderline in the left eye (p=0.0571). The relationship between acquired dyschromatopsia and exposure level also showed an increase in the odds ratio in the left eye but not in the right eye. Taken together, these results suggest that chronic low-level exposure to benzene can lead to acquired dyschromatopsia.
authors.affiliation: Department of Environmental Health, School of Public Health, Seoul National University, 28 YeonKeon-Dong, Jongro-Gu, Seoul 110-799, Republic of Korea.
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Lee
authors.forename: Ki Do
authors.initials: KD
authors.lastname: Eum
authors.forename: Sung-Il
authors.initials: SI
authors.lastname: Cho
authors.forename: Hae-Kwan
authors.initials: HK
authors.lastname: Cheong
authors.forename: Do Myung
authors.initials: do M
authors.lastname: Paek
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D001554:Benzene / Q000009:adverse effects*; D002617:Chemical Industry; D003118:Color Perception / Q000187:drug effects*; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000139:chemically induced* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D008875:Middle Aged; D009420:Nervous System / Q000187:drug effects / Q000503:physiopathology; D009784:Occupational Diseases / Q000139:chemically induced* / Q000503:physiopathology; D016273:Occupational Exposure; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012997:Solvents / Q000009:adverse effects*
chemical_list: D000393:Air Pollutants; D012997:Solvents; D001554:Benzene