title: Color-space distortions following long-term occupational exposure to mercury vapor.
abstract: Color vision was examined in subjects with long-term occupational exposure to mercury (Hg) vapor. The color vision impairment was assessed by employing a quantitative measure of distortion of individual and group perceptual color spaces. Hg subjects (n = 18; 42.1 ± 6.5 years old; exposure time = 10.4 ± 5.0 years; time away from the exposure source = 6.8 ± 4.6 years) and controls (n = 18; 46.1 ± 8.4 years old) were examined using two arrangement tests, D-15 and D-15d, in the traditional way, and also in a triadic procedure. From each subject's 'odd-one-out' choices, matrices of inter-cap subjective dissimilarities were derived and processed by non-metric multidimensional scaling (MDS). D-15d results differed significantly between the Hg-group and the control group (p < 0.05), with the impairment predominantly along the tritan axis. 2D perceptual color spaces, individual and group, were reconstructed, with the dimensions interpreted as the red-green (RG) and the blue-yellow (BY) systems. When color configurations from the Hg-group were compared to those of the controls, they presented more fluctuations along both chromatic dimensions, indicating a statistically significant difference along the BY axis. In conclusion, the present findings confirm that color vision impairments persist in subjects that have received long-term occupational exposure to Hg-vapor although, at the time of testing, they were presenting mean urinary concentration within the normal range for non-exposed individuals. Considering the advantages of the triadic procedure in clinical evaluation of acquired color vision deficiencies, further studies should attempt to verify and/or improve its efficacy.
authors.affiliation: Department of Psychology, University of Chicago, Chicago, IL 60637, USA. claudia@feitosa-santana.com
authors.forename: Claudia
authors.initials: C
authors.lastname: Feitosa-Santana
authors.forename: David L
authors.initials: DL
authors.lastname: Bimler
authors.forename: Galina V
authors.initials: GV
authors.lastname: Paramei
authors.forename: Nestor N
authors.initials: NN
authors.lastname: Oiwa
authors.forename: Mirella T S
authors.initials: MT
authors.lastname: Barboni
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Costa
authors.forename: Luiz C L
authors.initials: LC
authors.lastname: Silveira
authors.forename: Dora F
authors.initials: DF
authors.lastname: Ventura
mesh_terms: D000328:Adult; D003119:Color Perception Tests / Q000379:methods; D003117:Color Vision Defects / Q000139:chemically induced* / Q000175:diagnosis / Q000523:psychology; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008628:Mercury / Q000633:toxicity*; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000523:psychology; D016273:Occupational Exposure / Q000009:adverse effects; D010775:Photic Stimulation / Q000379:methods; D013028:Space Perception / Q000187:drug effects*
chemical_list: D008628:Mercury