Spatial and Seasonal Patterns of Pb, Cd, Ni, Cr, Cu, and Zn in Water and Soil Across Contrasting Land-Use Types: Relationships with Physicochemical Parameters and Total Metal Load

Abstract

Background: Heavy metal contamination remains a persistent environmental concern because metals are non-biodegradable, may accumulate in soil and water, and can be redistributed by runoff, dust deposition, drainage, and resuspension. Objective: This study assessed spatial and temporal patterns of Pb, Cd, Ni, Cr, Cu, and Zn in water and soil across contrasting land-use categories and examined their relationships with physicochemical variables. Methods: The dataset included six sites representing semi-rural reference, residential, hospital/urban service, traffic, industrial/cement, and agricultural/suburban settings. Monthly date stamps covered October 2025 to March 2026, with three replicates per site, month, and matrix, yielding 216 observations. Metals were determined after acid digestion by atomic absorption spectrophotometry. Descriptive statistics, Shapiro-Wilk tests, Kruskal-Wallis tests, Benjamini-Hochberg-adjusted Dunn comparisons, and Spearman correlations were applied separately for water and soil. Results: The industrial/cement site had the highest mean total measured metal load in water and soil, followed by the traffic site, whereas the semi-rural reference site had the lowest burden. Mean total load was 0.619 ± 0.223 mg/L in water and 334.19 ± 99.02 mg/kg dry weight in soil. Site-level differences were significant in both matrices, with a stronger spatial effect in soil. Water showed significant month/season grouping effects, but this temporal pattern was exploratory because the dataset covered only six months and spring was represented by one month. EC correlated strongly with total load in water and soil, while turbidity correlated moderately with water metal burden. Conclusion: The dataset supports a clear land-use gradient, with industrial/cement and traffic settings representing the main monitoring hotspots. The findings should be interpreted as total recoverable metal enrichment, not as direct toxicity, bioavailability, or source-apportionment evidence.