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. 2008 Apr-Jun;2(2):91-95.
doi: 10.1590/S1980-57642009DN20200003.

Neuropsychological alterations in mercury intoxication persist several years after exposure

Elaine Cristina Zachi  1 , Anita Taub  2 , Marcília de Araújo Medrado Faria  3 , Dora Fix Ventura  4
Affiliations

Neuropsychological alterations in mercury intoxication persist several years after exposure

Elaine Cristina Zachi et al. Dement Neuropsychol. 2008 Apr-Jun.

Abstract
in English, Portuguese

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.

Mercúrio metálico é um metal líquido e tóxico com ampla aplicação industrial. A exposição ocupacional ao metal ocorre principalmente por inalação. Previamente, comprometimento em várias funções neuropsicológicas foi constatado em ex-trabalhadores de fábrica de lâmpadas fluorescentes que haviam sido expostos ao vapor de mercúrio e estavam afastados da fonte de exposição por vários anos no momento do exame.

Objetivos: Reexaminar estas funções após 18 meses, com a finalidade de verificar a possível progressão do comprometimento.

Métodos: Treze participantes foram submetidos a testes de atenção, controle inibitório, memória verbal e visual, funções executivas, conhecimento semântico e inventários de depressão e ansiedade.

Resultados: Na linha de base, os ex-trabalhadores mostraram lentificação psicomotora e no processamento de informações, déficit de memória verbal espontânea, além de maiores sintomas de depressão e ansiedade comparados com controles (P<0,05). Comparações pareadas do grupo exposto na linha de base e 18 meses após indicaram pior desempenho em memória imediata (P<0,05). Não houve diferença nas demais medidas.

Conclusões: Embora a literatura mostre indícios de recuperação das funções, os efeitos neuropsicológicos relacionados ao mercúrio podem persistir por muitos anos.

Keywords: cognition disorders; mercury; mood; neuropsychological tests; occupational exposure.

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