Objective: To evaluate whether there are visual and neuropsychological decrements in workers with low exposure to Hg vapor.
Methods: Visual fields, contrast sensitivity, color vision, and neuropsychological functions were measured in 10 workers (32.5 +/- 8.5 years) chronically exposed to Hg vapor (4.3 +/- 2.8 years; urinary Hg concentration 22.3 +/- 9.3 microg/g creatinine).
Results: For the worst eyes, we found altered visual field thresholds, lower contrast sensitivity, and color discrimination compared with controls (P <0.05). There were no significant differences between Hg-exposed subjects and controls on neuropsychological tests. Nevertheless, duration of exposure was statistically correlated to verbal memory and depression scores.
Conclusions: Chronic exposure to Hg vapor at currently accepted safety levels was found to be associated with visual losses but not with neuropsychological dysfunctions in the sample of workers studied.