Long Term Exposure to Manganese in Rural Well Water Has No Neurological Effects

Abstract

ABSTRACT:Background: There is debate on the neurological impact of chronic exposure to Manganese (MN). Methods: MN burden from rural well water was studied cross-sectionally in two proband cohorts from rural dwellings located in northern Germany. Both cohorts had exposure times for up to 40 years and were separated on the basis of well water MN content. Group A (41 subjects; mean age 57.5 years) was exposed to MN water contents of at least 0.300 mg/1 (range 0.300 to 2.160), while group B (74 subjects; mean age 56.9 years) was exposed to concentrations of less than 0.050 mg/1. Both proband groups were homogenous with regard to age, sex, nutritional habits, and drug intake. Neurological assessments by clinical investigators blinded for proband's exposure status was done using structured questionnaires, standardized neurological examination with assessment of possible Parkinsonian signs by the Columbia University Rating Scale, and instrumental tests of fine motor coordination. Results: No significant difference in any neurological measure was found between groups. Results were not confounded by demographic and dietary features. Conclusion: Exposure to high body burden of MN does not result in detectable neurological impairment. Exposure to MN in drinking water does not seem to be a risk factor for idiopathic Parkinson's disease. RESUME: L'exposition a long terme au manganese dans l'eau de puits n'a pas de repercussion neurologique. Introduction: Les repercussions neurologiques d'une exposition chronique au manganese (MN) demeurent une source de controverse. Methodes: Nous avons effectue une 6tude transversale de la charge en MN chez deux cohortes de sujets habitant la campagne dans le nord de l'Allemagne. Chez les individus des deux cohortes, le temps d'exposition pouvait atteindre 40 ans. Le groupe A (41 sujets; 57.5 ans d'Sge moyen) avait 6t6 exposd a de l'eau dont la teneur en MN etait d'au moins 0.300 mg/1 (intervalle de 0.300 a 2.160), alors que le groupe B (74 sujets; 56.9 ans d'age moyen) avait 6t6 expose a des concentrations de moins de 0.050 mg/1. Les deux groupes de sujets fitaient homogenes quant a l'age, au sexe, aux habitudes alimentaires et a la prise de medicaments. Des investigateurs cliniques ignorant le niveau d'exposition des sujets ont effectue une evaluation neurologique au moyen d'un questionnaire structure, d'un examen neurologique standardise avec evaluation des signes parkinsonians au moyen de l'echelle de l'universite Columbia lorsque pertinent, ainsi que des 6preuves de motricite' fine. Resultats: Nous n'avons pas observe de difference significative pour quelque mesure que ce soit entre les deux groupes. Les resultat n'etaient pas influences par des particularites dfimographiques ou alimentaires. Conclusions: L'exposition a une charge corporelle elevee en MN ne provoque pas de deficit neurologique d6celable. L'exposition au MN dans l'eau potable ne semble pas etre un facteur de risque de la maladie de Parkinson.

Neurotoxic Effects of Low Level Exposure to Manganese in Human Populations

“…It should be noted that the highest Mn levels in drinking water in this study are a factor of 10 lower than the levels shown to cause severe manganese poisoning in the early Japanese study. On the other hand, a study in Germany did not demonstrate increased neurological impairment associated with Mn in drinking water (Vieregge et al, 1995). In this latter study, Mn drinking water levels for the most exposed group were lower than those for the most exposed group in the Greek study and the study population was younger.…”

Searching for a relationship between manganese and welding and Parkinson’s disease

“…Several studies have suggested that exposures to aluminum, copper, and lead are risk factors for PD, 10,73,74 but no such link has been found for manganese. 10,12,[74][75][76][77][78][79][80] In one study conducted in southern Quebec (Canada), involving 42 parkinsonian patients compared with a group of 84 matched controls, a slightly increased risk for PD was found to be associated with occupational exposure to manganese, iron, and aluminum, but this association did not reach statistical significance. 81 In a study of WWII Twins Cohort, involving 163 twin pairs, in which a blinded industrial hygienist estimated lifetime occupational manganese exposure intensity and duration, twins with PD were less likely to have ever been exposed to manganese than their control twin (OR ϭ 0.36) and had a shorter average duration of manganese exposure than did controls.…”

Hair Manganese and Hyperactive Behaviors: Pilot Study of School-Age Children Exposed through Tap Water

“…The reduced compensatory capacity of older persons’ nervous systems has been proposed as an explanatory mechanism for their apparent vulnerability (Kondakis et al 1989). However, Vieregge et al (1995) did not observe differences when comparing neurologic status and neurotoxic symptoms in adults > 50 years of age drinking water containing Mn concentrations 300–2,160 μg/L to those drinking water containing Mn < 50 μg/L. Small sample size, wide variation of Mn concentrations, and the use of extensive exclusion criteria that could have excluded persons presenting neurotoxic effects of Mn exposure (i.e., history of treatment for psychiatric disorder, neuroorthopedic incapacity for movement of hand and fingers) might have limited the validity of this study.…”