Heavy metal contents, mobility and origin in agricultural topsoils of the Galápagos Islands

Tamara C. Dinter, Martin H. Gerzabek, Markus Puschenreiter, Bjarne W. Strobel, Paulina M. Couenberg, Franz Zehetner*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

26 Citations (Scopus)
23 Downloads (Pure)

Abstract

While the Galápagos Islands have been renowned for their unique flora and fauna since the time of Charles Darwin, the soils of the isolated island chain have been mostly overlooked and little information on their heavy metal contents is available. The aim of this study was therefore to examine the total heavy metal (Cd, Co, Cr, Cu, Ni, Pb, U, Zn) contents of soils from the agricultural areas on islands Isabela, Santa Cruz and San Cristóbal, and identify trends with duration of exposure to weathering processes. Additionally, the mobility of these elements was assessed using ammonium nitrate extraction. In general, levels of Cd, Co, Cr, Cu, Ni and Zn were high compared to other world locations, while Pb levels were low and U levels were similar. Ni, Co, Cr, and to a lesser extent Pb and U tended to accumulate with increasing weathering duration. Soil concentrations of Cd, Zn, Cu, and possibly Pb and U, may have been influenced by use of agrochemicals, particularly on Santa Cruz Island. Mobility of Cd displayed an increasing trend with soil age, while Ni mobility decreased. Many soils had total contents of Cd, Co, Cr, Cu, Ni and Zn above threshold values indicating possible ecological or health risks. Systematic examination of trace element contents in soils from pristine national park areas would further assist in the delineation of background levels and the development of soil quality standards to ensure crop quality, animal and human health on this unique island chain.

Original languageEnglish
Article number129821
JournalChemosphere
Volume272
Number of pages11
ISSN0045-6535
DOIs
Publication statusPublished - 2021

Keywords

  • Agricultural soils
  • Aqua regia
  • Galápagos Islands
  • Heavy metals
  • Trace elements
  • Volcanic ash soils

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