Spatial Distribution of Mercury and Arsenic Levels in Water, Soil and Cassava Plants in a Community with Long History of Gold Mining in Tanzania

  • Elias C. NyanzaEmail author
  • Deborah Dewey
  • Deborah S. K. Thomas
  • Mark Davey
  • Sospatro E. Ngallaba


This study examined the spatial distribution of total mercury (THg) and total arsenic (TAs) in water, soil and cassava (Manihot esculenta) (leaves and roots) samples taken from areas in Rwamagasa village in northwestern Tanzania where daily living activities occur in close proximity to extensive artisanal and small scale gold mining. Results indicated that 33.3 % of the water sources had THg levels above the WHO guideline of 1.0 µg/L for safe drinking water, and 12.5 % had TAs levels above 10 µg/L. Cassava leaves were found to have higher THg (ranging from 8.3 to 167 µg/kg) and TAs (ranging from 60 to 1,120 µg/kg) levels than cassava roots, which ranged between 1.2–8.3 µg/kg for THg and 25–310 µg/kg for TAs. Concentrations of THg and TAs in soil samples ranged between 5.8–1,759 and 183–20,298 µg/kg, respectively. Both THg and TAs were found to be distributed throughout Rwamagasa village.


Mercury Arsenic Artisanal gold mining Contamination Spatial distribution 



The authors acknowledge the Catholic University of Health and Allied Sciences-Bugando, the University of Calgary and the University of Colorado, Denver. A special thank you goes to African Eagle Resources who contributed funding to support this project. The authors would also like to thank all the participants in this study. The authors also declare that they have no competing interests. It should be noted that Twigg Gold is not engaged or associated with artisanal mining in the Rwamagasa belt or anywhere else.


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Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Elias C. Nyanza
    • 1
    Email author
  • Deborah Dewey
    • 2
  • Deborah S. K. Thomas
    • 3
  • Mark Davey
    • 4
  • Sospatro E. Ngallaba
    • 1
  1. 1.School of Public HealthCatholic University of Health and Allied Sciences, BugandoMwanzaTanzania
  2. 2.Departments of Pediatrics and Community Health SciencesUniversity of CalgaryCalgaryCanada
  3. 3.Department of Geography and Environmental SciencesUniversity of Colorado DenverDenverUSA
  4. 4.Exploration UnitTwigg Gold LimitedMwanzaTanzania

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