Water, Air, & Soil Pollution

, 224:1415 | Cite as

Particulate and Dissolved Trace Element Concentrations in Three Southern Ecuador Rivers Impacted by Artisanal Gold Mining

  • Gregory T. Carling
  • Ximena Diaz
  • Marlon Ponce
  • Lester Perez
  • Luis Nasimba
  • Eddy Pazmino
  • Abigail Rudd
  • Srinivas Merugu
  • Diego P. Fernandez
  • Bruce K. Gale
  • William P. JohnsonEmail author


Water and sediment samples were collected along river transects at three artisanal gold mining areas in southern Ecuador: Nambija, Portovelo-Zaruma, and Ponce Enriquez. Samples were analyzed for a suite of major and trace elements, including filtered/unfiltered water samples and stream flow measurements to determine dissolved/particulate loads. Results show that the Q. Calixto, Calera, and Siete rivers (corresponding to Nambija, Portovelo-Zaruma, and Ponce Enriquez mining areas, respectively) have substantial trace element contamination due to mining inputs. Dissolved concentrations were elevated at Calera and Siete relative to Q. Calixto, possibly reflecting the input of soluble cyano-metal complexes in mining zones where cyanidation is used in ore processing. A negative correlation was found between MeHg:THg ratios and pH, indicating an inverse relationship of mercury methylation with cyanidation (since cyanidation increases water pH). This was the first comprehensive study to examine an extensive suite of trace elements in both water and sediment at the three main gold mining areas of southern Ecuador, including dissolved and particulate loads, and the first study to report MeHg concentrations in the mercury-contaminated rivers.


Cyanidation Methyl mercury Trace metals Particulate loads Dissolved loads Ecuador 



This work was conducted under a project-scoping award (0964836) from the US National Science Foundation Office of International Science and Education. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. We wish to thank Dr. Diósgrafo Chamba, former Executive Director of the Ecuadorian Agency of Regulation and Control for Mining (ARCOM), and the Ecuadorian National Institute of Research in Geology, Mining and Metallurgy (INIGEMM) for providing personnel for field work as well as vehicles and drivers for transportation to field sites. We also thank Met. Carlos Naranjo, Executive Director of the Ecuadorian National Institute of Meteorology and Hydrology (INAMHI) for providing personnel and equipment for flow measurements in the rivers. We thank Roberto Garcia for providing GIS maps of the study areas. We are grateful to the drivers and other field assistants for making this work possible and feasible, and to mine operators who allowed access to their property for sampling.

Supplementary material

11270_2012_1415_MOESM1_ESM.doc (94 kb)
ESM 1 (DOC 94 kb)
11270_2012_1415_MOESM2_ESM.xls (56 kb)
ESM 2 (XLS 56 kb)


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Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Gregory T. Carling
    • 1
    • 6
  • Ximena Diaz
    • 2
  • Marlon Ponce
    • 3
  • Lester Perez
    • 4
  • Luis Nasimba
    • 3
  • Eddy Pazmino
    • 1
  • Abigail Rudd
    • 1
  • Srinivas Merugu
    • 1
  • Diego P. Fernandez
    • 1
  • Bruce K. Gale
    • 5
  • William P. Johnson
    • 1
    Email author
  1. 1.Department of Geology & GeophysicsUniversity of UtahSalt Lake CityUSA
  2. 2.Department of Extractive MetallurgyEscuela Politécnica NacionalQuitoEcuador
  3. 3.Instituto Nacional de Investigación Geológico Minero Metalúrgico, INIGEMMQuitoEcuador
  4. 4.Instituto Nacional de Meteorología e Hidrología, INAMHIQuitoEcuador
  5. 5.Department of Mechanical EngineeringUniversity of UtahSalt Lake CityUSA
  6. 6.Department of Geological SciencesBrigham Young UniversityProvoUSA

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