About the Authors

Kerry Sidwell Wilson

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Visualization, Writing – original draft, Writing – review & editing

KerryW@nioh.ac.za

Affiliations Epidemiology and Surveillance Section, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, Johannesburg, South Africa, Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Witwatersrand, South Africa

Vusi Ntlebi

Roles Writing – review & editing

Affiliation Epidemiology and Surveillance Section, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, Johannesburg, South Africa

Felix Made

Roles Formal analysis, Methodology, Writing – review & editing

Affiliation Epidemiology and Surveillance Section, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, Johannesburg, South Africa

Natasha Sanabria

Roles Investigation, Writing – original draft, Writing – review & editing

Affiliation Toxicology and Biochemistry Department, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, South Africa

Melissa Vetten

Roles Investigation, Writing – original draft, Writing – review & editing

Affiliation Toxicology and Biochemistry Department, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, South Africa

Jitcy Joseph

Roles Writing – original draft, Writing – review & editing

Affiliation Toxicology and Biochemistry Department, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, South Africa

Graham Chin

Roles Methodology, Supervision

Affiliation National Safety Health and Environment Department, National Institute for Occupational Health, A Division of National Health Laboratory Services, Braamfontein, South Africa

David Jones

Roles Conceptualization, Supervision

Affiliation National Safety Health and Environment Department, National Institute for Occupational Health, A Division of National Health Laboratory Services, Braamfontein, South Africa

Nonhlanhla Tlotleng

Roles Formal analysis, Investigation, Methodology, Visualization, Writing – review & editing

Affiliation Epidemiology and Surveillance Section, National Institute for Occupational Health, A Division of National Health Laboratory Service, Braamfontein, Johannesburg, South Africa

Competing Interests

I have read the journal’s policy and the authors of this manuscript have the following competing interests: One author is involved in establishing the information system used here to provide the data in the local government health departments. This does not alter our adherence to PLOS ONE policies on sharing data and materials.