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Dementia & Neuropsychologia

Print version ISSN 1980-5764

Dement. neuropsychol. vol.2 no.2 São Paulo Apr./June 2008

https://doi.org/10.1590/S1980-57642009DN20200003 

Original Articles

Neuropsychological alterations in mercury intoxication persist several years after exposure

Alterações neuropsicológicas na intoxicação mercurial persistem após vários anos do afastamento à exposição

Elaine Cristina Zachi 1  

Anita Taub 2  

Marcília de Araújo Medrado Faria 3  

Dora Fix Ventura 4  

1M.Sc. Departamento de Psicologia Experimental, Núcleo de Neurociências e Comportamento, Instituto de Psicologia, Universidade de São Paulo, São Paulo SP, Brazil.

2M.Sc. Instituto de Psiquiatria da Universidade de São Paulo, São Paulo SP, Brazil.

3Ph.D. Departamento de Medicina Legal, Ética Médica e Medicina Social e do Trabalho, Faculdade de Medicina, Universidade de São Paulo, São Paulo SP, Brazil.

4Ph.D. Departamento de Psicologia Experimental, Núcleo de Neurociências e Comportamento, Instituto de Psicologia, Universidade de São Paulo, São Paulo SP, Brazil.


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

Resumo

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.

Palavras-chave: mercúrio; exposição ocupacional; cognição; testes neuropsicológicos; humor

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

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Received: April 22, 2008; Accepted: May 21, 2008

Elaine Cristina Zachi - Instituto de Psicologia da Universidade de São Paulo - Av. Prof. Mello Moraes, 1721 / Bloco A / sala D-09 - 05508-900 São Paulo SP- Brazil. E-mail: elainez@usp.br

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