COLOR-VISION LOSS IN WORKERS EXPOSED TO ELEMENTAL MERCURY-VAPOR

We evaluated colour vision in 33 workers exposed to elemental mercury (Hg) vapour and in 33 referents matched for sex, age, alcohol consumpt ion and cigarette smoking. The results were expressed as colour confus ion index (CCI). In the workers urinary excretion of Hg (HgU) ranged f rom 28 to 287 mu g/g creatinine. Subclinical colour vision loss, mainl y in the blue-yellow range, was observed in the workers. This effect w as related to exposure, as indicated by the correlation between HgU an d CCI (r = 0.488, P < 0.01). In the workers whose HgU exceeded 50 mu g /g creatinine, mean CCI was significantly increased compared to the ma tched referents. The results suggest that exposure to elemental Hg ind ucing HgU values exceeding 50 mu g/g creatinine can induce a dose-rela ted colour vision loss.