Environmental Exposure to Trace Metals and Fluoride in Drinking Water and Soil: A Study Protocol Evaluating Multi-Index Dental Pathologies in Mining-Affected Towns of Mpumalanga, South Africa

Intensive mining in Mpumalanga, South Africa, risks contaminating drinking water and topsoil with toxic trace metals. While systemic toxicological impacts are well-documented, the specific relationship between this multi-matrix environmental exposure and localized dental hard tissue pathologies remains critically under-researched. This study protocol outlines a standardized, multidisciplinary approach to evaluate these oral health impacts. Field sampling and clinical screenings are scheduled across an 11-month execution timeline (January 2027 to November 2027). This cross-sectional protocol features three integrated phases: (1) Environmental Geochemistry: Drinking water (n = 120) from source, municipal, and point-of-use taps, alongside concurrent residential topsoil samples (n = 60), will be analysed for trace metals and metalloids (Pb, Cd, Cr, Mn, As, Fe, Cu, and Zn) using ICP-MS/ICP-OES, and fluoride (F−) using an Ion-Selective Electrode. (2) Clinical Assessment: Registered dental professionals will screen a resident cohort (N = 388) using Dean’s Index for fluorosis, the DMFT index for dental caries, and the Developmental Defects of Enamel (DDE) index. (3) Health Risk Assessment: Human health risks will be quantified via Chronic Daily Intake (CDI), Target Hazard Quotient (THQ), and cumulative Hazard Index (HI) models. This protocol will generate high-resolution spatial contamination maps using Inverse Distance Weighting (IDW) interpolation and establish predictive multivariate regression models correlating environmental metal burdens with clinical oral pathologies. Ultimately, it provides a legally defensible scientific baseline for provincial water quality policy adjustments and targeted public health interventions in mining-affected communities.