TY - JOUR
T1 - Geochemical fingerprinting to determine sediment source contribution and improve contamination assessment in mining-impacted floodplains in the Philippines
AU - Domingo, Justine Perry T.
AU - Ngwenya, Bryne t.
AU - Attal, Mikaël
AU - David, Carlos Primo C.
AU - Mudd, Simon M.
N1 - Funding Information:
This work was funded by the British Council and the Department of Science and Technology - Science Education Institute through the DOST-Newton PhD Scholarship awarded to Justine Domingo (Grant Number 279692019), with additional financial support from the University of Edinburgh through a Moray Endowment Fund Award and a Research Development Fund Award (School of GeoSciences). The authors would like to thank the mining companies in Santa Cruz that allowed access to their mining tenements and assisted in the collection of sediment samples. Special thanks to the Environment Monitoring Laboratory, Earth Materials Science Laboratory, and Nannoworks Laboratory (University of the Philippines – National Institute of Geological Sciences), and to the Philippine Nuclear Research Institute - Nuclear Materials Research Section for the use of facilities and equipment for sample preparation; to Dr. Laetitia Pichevin, Dr. Gavin Sim, and Mr. Steve Mowbray from the School of GeoSciences for assisting with the laboratory analyses.
Funding Information:
This work was funded by the British Council and the Department of Science and Technology - Science Education Institute through the DOST-Newton PhD Scholarship awarded to Justine Domingo (Grant Number 279692019), with additional financial support from the University of Edinburgh through a Moray Endowment Fund Award and a Research Development Fund Award (School of GeoSciences). The authors would like to thank the mining companies in Santa Cruz that allowed access to their mining tenements and assisted in the collection of sediment samples. Special thanks to the Environment Monitoring Laboratory, Earth Materials Science Laboratory, and Nannoworks Laboratory (University of the Philippines – National Institute of Geological Sciences), and to the Philippine Nuclear Research Institute - Nuclear Materials Research Section for the use of facilities and equipment for sample preparation; to Dr. Laetitia Pichevin, Dr. Gavin Sim, and Mr. Steve Mowbray from the School of GeoSciences for assisting with the laboratory analyses.
Publisher Copyright:
© 2023 The Authors
PY - 2023/12/1
Y1 - 2023/12/1
N2 - Constraining the main sediment sources and pathways across landscapes impacted by anthropogenic activity is essential to limit the dispersal of sediment-borne contaminants, especially in global conservation priority areas. This study examined the provenance, partitioning, and enrichment of metals in the floodplain of the mining-affected Santa Cruz catchment, The Philippines. Composite geochemical fingerprinting of fine sediment samples (n = 36) was performed using a stepwise statistical screening procedure (range test, Kruskal-Wallis H test, discriminant function analysis) to derive the optimum set of tracers. Using a standard unmixing model, flood deposits downstream of the mining areas were shown to be predominantly mining-induced (71.9 ± 7.7 %), followed by natural erosion from gullies and stream banks (15.1 ± 11.0 %) and agricultural sediment (13.0 ± 5.1 %). Element partitioning data (Log Kd = 1.3–6.6) during a high flow event indicated that metals are dominantly associated and transported via suspended particulate matter. Background concentrations of Ni and Cr were found to be orders of magnitude higher than the threshold values set by international sediment quality guidelines (SQGs), emphasizing the need for site-specific SQGs in mineralised areas. Enrichment factor values indicated low to significant contamination of flood deposits relative to natural and agricultural sediment (EF 1.0–5.5). Furthermore, it was demonstrated that using different conservative elements could considerably influence the enrichment factor calculation. Based on tracer screening tests, Th was shown to be the most suitable reference element. The findings provide new insights on the application of geochemical tracers in a mining setting and integrating fingerprinting approaches with traditional assessment techniques to improve the reliability of contamination risk assessment in other areas facing similar sediment pollution problems.
AB - Constraining the main sediment sources and pathways across landscapes impacted by anthropogenic activity is essential to limit the dispersal of sediment-borne contaminants, especially in global conservation priority areas. This study examined the provenance, partitioning, and enrichment of metals in the floodplain of the mining-affected Santa Cruz catchment, The Philippines. Composite geochemical fingerprinting of fine sediment samples (n = 36) was performed using a stepwise statistical screening procedure (range test, Kruskal-Wallis H test, discriminant function analysis) to derive the optimum set of tracers. Using a standard unmixing model, flood deposits downstream of the mining areas were shown to be predominantly mining-induced (71.9 ± 7.7 %), followed by natural erosion from gullies and stream banks (15.1 ± 11.0 %) and agricultural sediment (13.0 ± 5.1 %). Element partitioning data (Log Kd = 1.3–6.6) during a high flow event indicated that metals are dominantly associated and transported via suspended particulate matter. Background concentrations of Ni and Cr were found to be orders of magnitude higher than the threshold values set by international sediment quality guidelines (SQGs), emphasizing the need for site-specific SQGs in mineralised areas. Enrichment factor values indicated low to significant contamination of flood deposits relative to natural and agricultural sediment (EF 1.0–5.5). Furthermore, it was demonstrated that using different conservative elements could considerably influence the enrichment factor calculation. Based on tracer screening tests, Th was shown to be the most suitable reference element. The findings provide new insights on the application of geochemical tracers in a mining setting and integrating fingerprinting approaches with traditional assessment techniques to improve the reliability of contamination risk assessment in other areas facing similar sediment pollution problems.
U2 - 10.1016/j.apgeochem.2023.105808
DO - 10.1016/j.apgeochem.2023.105808
M3 - Article
SN - 0883-2927
VL - 159
JO - Applied geochemistry
JF - Applied geochemistry
M1 - 105808
ER -