Environ Monit Assess. 2026 Jun 18;198(7):738. doi: 10.1007/s10661-026-15588-4.
ABSTRACT
Understanding the distribution and controlling factors of trace elements in topsoils is essential for evaluating soil quality and potential environmental risks. This study investigated the concentrations, spatial distribution, enrichment characteristics, and environmental controls of trace elements (Co, Cu, Mo, Ni, and Zn) in surface soils of Cao Bang Province, northern Vietnam. Trace element concentrations were determined using inductively coupled plasma mass spectrometry (ICP-MS) following acid digestion of soil samples. The concentrations ranged from below detection limit (BDL) to 278.11 mg kg-1 for Co, 0.26-269.32 mg kg-1 for Cu, BDL-15.12 mg kg-1 for Mo, BDL-482.58 mg kg-1 for Ni, and 0.02-947.05 mg kg-1 for Zn. Spatial interpolation revealed considerable variability across the study area, although most soils exhibited low to moderate concentrations. Enrichment factor (EF) values were generally below 3, indicating minimal to moderate enrichment and suggesting that these elements mainly originate from natural lithogenic sources. Principal component analysis showed strong associations among Co, Cu, Ni, and Zn, whereas Mo displayed a distinct behavior due to its sensitivity to oxidation reduction conditions and soil pH, which differs from the other transition metals. Statistical analyses indicated that topography and parent materials had no significant influence (p > 0.05) on trace element concentrations, while elevation showed a weak but significant effect on Ni (p = 0.049). Overall, the distribution of trace elements in Cao Bang topsoils is largely controlled by natural geochemical processes and long-term weathering, with limited evidence of significant anthropogenic contamination. These results provide important baseline information for topsoil environmental assessment and future monitoring in northern Vietnam.
PMID:42313280 | DOI:10.1007/s10661-026-15588-4
