Heavy metal contamination from historical mining remains a persistent environmental concern in the Tri-State Mining District, which spans Missouri, Kansas, and Oklahoma. This study evaluated the effectiveness of handheld X-ray fluorescence (XRF) for rapid soil screening at five sites within the Oronogo–Duenweg Mining Belt near Joplin, Missouri. Each site had undergone varying degrees of remediation, and five or more surface soil samples (<500 µm fraction) were collected from each. Elemental concentrations of Pb, Zn, Cu, Fe, and Cd were analyzed using an Olympus Vanta handheld XRF in GeoChem mode. Cd was below the detection limit (<5 mg/kg) at all sites.

Statistical comparisons (ANOVA, Tukey HSD, and Spearman correlation) revealed that Pb and Zn concentrations were significantly elevated at Site 1, with Site 3 showing moderate enrichment and Sites 2, 4, and 5 exhibiting lower levels. Cu concentrations differed only slightly among sites. To account for differences in soil composition, metal concentrations were also normalized to Fe, which improved statistical resolution and clarified site-level distinctions, particularly for Cu.

Boxplots and coefficient of variation analysis highlighted high within-site variability at Sites 1 and  3, suggesting uneven residual contamination. The strong correlation between Pb and Zn (ρ = 0.78) supports a shared source, consistent with legacy chat material.

These findings confirm handheld XRF, when paired with Fe normalization and robust statistical methods, as a valuable tool for screening lead–zinc contamination in post-remediation soils. The approach offers rapid, non-destructive analysis to support environmental monitoring, guide follow-up testing, and prioritize remediation efforts in complex field conditions.