Manganese exposure, parkinsonian signs, and quality of life in South African mine workers

Authors

Wendy W. Dlamini, Occupational Health Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.
Gill Nelson, Occupational Health Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.
Susan Searles Nielsen, Department of Neurology, Washington University School of Medicine, St Louis, Missouri.
Brad A. Racette, Occupational Health Division, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.

Document Type

Article

Abstract

BACKGROUND: Manganese (Mn) neurotoxicity is associated with parkinsonism; the associated motor deficits can affect individuals' quality of life (QoL). We investigated associations between Mn exposure, parkinsonian signs, and QoL in Mn mine workers. METHODS: We assessed parkinsonian signs and QoL in 187 black South African Mn mine workers, using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3) and the Parkinson Disease Questionnaire (PDQ-39), respectively. We estimated cumulative Mn exposure in mg Mn/m -years using complete occupational histories and a job-exposure matrix. We investigated the cross-sectional association between cumulative Mn exposure and UPDRS3 score, and the UPDRS3 score and PDQ-39, adjusting for age, using linear regression. RESULTS: Participants' mean age was 41.8 years (range, 21-67 years); 97.3% were male. Estimated mean cumulative Mn exposure at the time of examination was 5.4 mg Mn/m -years, with a mean of 14.0 years working in a Mn mine. The mean UPDRS3 score was 10.1 and 25.7% of the workers had a UPDRS3 score greater than or equal to 15. There was a U-shaped dose-response relation between cumulative Mn exposure and UPDRS3 score, with a positive association up to 15 mg Mn/m -years of exposure and an inverse association thereafter. Greater UPDRS3 scores were associated with poorer self-reported QoL. CONCLUSION: In this cohort of employed Mn mine workers, parkinsonian signs were common and were associated with both estimated cumulative Mn exposure and poorer QoL.

Medical Subject Headings

Adult; Aged; Cross-Sectional Studies; Female; Humans; Male; Manganese (toxicity); Middle Aged; Miners; Occupational Diseases (chemically induced, epidemiology); Occupational Exposure (adverse effects); Parkinsonian Disorders (chemically induced, epidemiology); Quality of Life; South Africa (epidemiology); Surveys and Questionnaires

Publication Date

1-1-2020

Publication Title

American journal of industrial medicine

E-ISSN

1097-0274

Volume

63

Issue

1

First Page

36

Last Page

43

PubMed ID

31647574

Digital Object Identifier (DOI)

10.1002/ajim.23060

Recommended Citation

Dlamini, Wendy W.; Nelson, Gill; Nielsen, Susan Searles; and Racette, Brad A., "Manganese exposure, parkinsonian signs, and quality of life in South African mine workers" (2020). Neurology. 1147.
https://scholar.barrowneuro.org/neurology/1147