Abstract
Elemental mercury is a liquid toxic metal widely used in industry. Occupational exposure occurs mainly via inhalation. Previously, neuropsychological assessment detected deficits in former workers of a fluorescent lamp plant who had been exposed to elemental mercury vapor and were away from exposure for several years at the time of examination.
Objectives:
The purpose of this work was to reexamine these functions after 18 months in order to evaluate their progression.
Methods:
Thirteen participants completed tests of attention, inhibitory control, verbal/visual memory, psychomotor speed, verbal fluency, visuomotor ability, executive function, semantic knowledge, and depression and anxiety inventories on 2 separate occasions.
Results:
At baseline, the former workers indicated slower psychomotor and information processing speed, verbal spontaneous recall memory impairment, and increased depression and anxiety symptoms compared to controls (P<0.05). Paired comparisons of neuropsychological functioning within the exposed group at baseline and 1.5 years later showed poorer immediate memory performance (P<0.05). There were no differences on other measures.
Conclusions:
Although the literature show signs of recovery of functions, the neuropsychological effects related to mercury exposure are found to persist for many years.
Key words:
mercury; occupational exposure; cognition disorders; neuropsychological tests; mood