Neurobehavioural effects of occupational exposure to cadmium: a cross sectional epidemiological study

Abstract

Background-A patient with unexplained minor behavioural changes associated with an axonal sensorimotor polyneuropathy had a history of chronic occupational exposure to cadmium (Cd). Although animal studies have shown that Cd is a potent neurotoxicant, little is known about its toxicity for the human central nervous system. The aim of this study was to investigate the toxic potential of chronic occupational exposure to Cd on neurobehavioural functions. Methods-A cross sectional epidemiological study was conducted in a group of Cd workers and an age matched control group. Eighty nine adult men (42 exposed to Cd and 47 control workers) were given a blinded standardised examination that consisted of computer assisted neurobehavioural tests (neurobehavioural examination system), a validated questionnaire to assess neurotoxic complaints (neurotoxicity symptom checklist-60, NSC-60), and a standardised self administered questionnaire to detect complaints consistent with peripheral neuropathy and dysfunction of the autonomic nervous system. Historical and current data on biomonitoring of exposure to Cd, either the highest value of Cd in urine (CdU in µg Cd/g creatinine) of each Cd worker during work (CdU max ) or the current value (CdUcurrent ) of each control, were available as well as data on microproteinuria.

Avaliação audiométrica de trabalhadores ocupacionalmente expostos a ruído e cádmio

“…Foi verificado que podem ocorrer alterações neurológicas em indivíduos expostos ao cádmio, porém com função renal preservada e baixas concentrações do metal nos exames laboratoriais disponíveis 27 . Uma maneira de tentar se assegurar que nenhum indivíduo exposto a agentes possivelmente ototóxicos em concomitância ao ruído, ou mesmo sem este, tenha alteração auditiva, é a realização de testes audiométricos periódicos.…”

“…Os achados têm sido favoráveis à hipótese do cádmio ter uma participação no desenvolvimento da polineuropatia 26 . 27 . O conhecimento disponível para a compreensão dos aspectos ocupacionais da exposição ao cádmio é ainda fragmentário, muitas vezes sendo necessário fazer inferência a partir de estudos epidemiológicos e em animais.…”

Ameliorating Effect of Aqueous Garlic Extract Supplementation on Cadmium Induced Toxicity in Albino Mice.

“…In several experimental models, it has been reported that Cd induces oxidative damage in brain mitochondria (Abib et al, 2011;Chen et al, 2011 (Sena and Chandel, 2012). It has been reported that Cd exposure produced long-term impairments of neurobehavioral status such as alterations in attention and memory as well as in the psychomotor and visuomotor functioning and speed in workers (Viaene et al, 2000;Haider et al, 2015).…”

Ameliorating Effect of Vitamin-E Against Cadmium (Cd) Induced Brain Oxidative Damage in Albino Rats.

“…Monroe and Halvorsen, 2006 provided evidence that CdCl2 increases oxidative stress in nervous cells. In experimental studies with animals, cadmium can induce neurotoxicity with a wide spectrum of clinical entities including neurological disturbance (Viaene et al, 2000). Changes in the normal neurochemistry of the brain (Gutierrez-Reyes et al, 1998), several authors have shown that antioxidants should be one of the important components of an effective treatment of cadmium poisoning (Valko et al, 2006).…”