SEGH Articles

Global dispersion of trace metals in South America

04 November 2014
Pre-Hispanic metallurgical activities released enough metals to be transported throughout the entire South American continent.

Our recent study of a peat bog in remote Tierra del Fuego and published in PLOS ONE revealed that a part of trace metals – namely copper, lead, antimony and tin – originating from pre-Hispanic metallurgical activities can be recorded in Southern South America. It highlights for the first time that although of relatively small scale, pre-Hispanic metallurgical activities released enough metals to be transported throughout the entire South American continent through favourable wind trajectories. We also found that recent coal, gold and oil rushes released substantial amounts of local lead in the Southern American atmosphere. The uniqueness of these finding connects a number of different fields of research (geochemistry, archaeology, geology, atmospheric sciences) and has many important implications for our understanding of ancient metallurgy, and its legacy on trace metal emission, transport and deposition. First, it provides a scientific answer to a series of observations and questions that have puzzled the archaeological community for decades: (i) how large were the metal exploration and processing in pre-Hispanic times (as only point sources or artefacts have been found); (ii) was there a continuum between the metallurgical activities from different civilizations; and (iii) how far were metallurgical by-products transported via the atmosphere, and how they impacted the environment. Second, our finding will lead to a general agreement that past atmospheric circulation had a secondary North to South wind trajectory, which is opposed to the actual Westerly wind system dominating in South America. This mechanism evidenced by our HYSPLIT modelling and the fact that pre-Hispanic metals were transported to Tierra del Fuego, directly connects the geological cycles of trace elements with past atmospheric dust cycles, wind circulation and climate. 

Picture 1. A partial view of the Karukinka peat bog complexe. Photo Courtesy J-Y De Vleeschouwer

Picture 2. F. De Veeschouwer and colleagues open a peat core containing several thousands of years of information about past metal and dust deposition, climate and environment. Photo Courtesy G. Le Roux

Picture 3. Outcrop of the ancient coal mine “Mina Elena” in South Patagonia. Photo Courtesy G. Le Roux

You can download our article in open access in PLOS ONE.

For more information about trace metals in peat, read our review in PAGES.

To know more about our research in South America and in peatlands in general, connect to our project webpage and our facebook page.


F. De Vleeschouwer - SEGH Member and former SEGH 2013 Conference Chairman



De Vleeschouwer F, Vanneste H, Mauquoy D, Piotrowska N, Torrejon F, et al. (2014) Emissions from Pre-Hispanic Metallurgy in the South American Atmosphere. PLoS ONE 9(10): e111315. doi:10.1371/journal.pone.0111315



Keep up to date

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Fate and partitioning of heavy metals in soils from landfill sites in Cape Town, South Africa: a health risk approach to data interpretation 2019-06-14


    The fate and persistence of trace metals in soils and sludge from landfill sites are crucial in determining the hazard posed by landfill, techniques for their restoration and potential reuse purposes of landfill sites after closure and restoration. A modified European Community Bureau of Reference’s (BCR) sequential extraction procedure was applied for partitioning and evaluating the mobility and persistence of trace metals (As, Cd, Cr, Cu, Ni, Pb, Sb, Se, Zn) in soils from three landfill sites and sludge sample from Cape Town, South Africa. Inductively coupled plasma optical emission spectroscopy was used to analyze BCR extracts. The mobility sequence based on the BCR mobile fraction showed that Cu (74–87%), Pb (65–80%), Zn (59–82%) and Cd (55–66%) constituted the mobile metals in the soils from the three sites. The mobility of Cu, Zn and Ni (> 95%) was particularly high in the sludge sample, which showed significant enrichment compared to the soil samples. Geo-accumulation index (Igeo) and risk assessment code were used to further assess the environmental risk of the metals in the soils. Exposure to the soils and sludge did not pose any non-cancer risks to adult and children as the hazard quotient and hazard index values were all below the safe level of 1. The cancer risks from Cd, Cr and Ni require that remedial action be considered during closure and restoration of the landfill sites.

  • An investigation into the use of < 38 µm fraction as a proxy for < 10 µm road dust particles 2019-06-13


    It is well documented that a large portion of urban particulate matters is derived from road dust. Isolating particles of RD which are small enough to be inhaled, however, is a difficult process. In this study, it is shown for the first time that the < 38 µm fraction of road dust particles can be used as a proxy for road dust particles < 10 µm in bioaccessibility studies. This study probed similarities between the < 10 and < 38µm fractions of urban road dust to show that the larger of the two can be used for analysis for which larger sample masses are required, as is the case with in vitro analysis. Road dust, initially segregated to size < 38 µm using sieves, was again size segregated to < 10 µm using water deposition. Both the original < 38 µm and the separated < 10 µm fractions were then subject to single particle analysis by SEM–EDX and bulk analysis by ICP-OES for its elemental composition. Dissolution tests in artificial lysosomal fluid, representative of lung fluid, were carried out on both samples to determine % bioaccessibility of selected potentially harmful elements and thus probe similarities/differences in in vitro behaviour between the two fractions. The separation technique achieved 94.3% of particles < 10 µm in terms of number of particles (the original sample contained 90.4% as determined by SEM–EDX). Acid-soluble metal concentration results indicated differences between the samples. However, when manipulated to negate the input of Si, SEM–EDX data showed general similarities in metal concentrations. Dissolution testing results indicated similar behaviour between the two samples in a simulated biological fluid.

  • Degradation of petroleum hydrocarbons in unsaturated soil and effects on subsequent biodegradation by potassium permanganate 2019-06-13


    To date, the oxidation of petroleum hydrocarbons using permanganate has been investigated rarely. Only a few studies on the remediation of unsaturated soil using permanganate can be found in the literature. This is, to the best of our knowledge, the first study conducted using permanganate pretreatment to degrade petroleum hydrocarbons in unsaturated soil in combination with subsequent bioaugmentation. The pretreatment of diesel-contaminated unsaturated soil with 0.5-pore-volume (5%) potassium permanganate (PP) by solution pouring and foam spraying (with a surfactant) achieved the total petroleum hydrocarbon (TPH) removal efficiencies of 37% and 72.1%, respectively. The PP foam, when coupled with bioaugmentation foam, further degraded the TPH to a final concentration of 438 mg/kg (92.1% total reduction). The experiment was conducted without soil mixing or disturbance. The relatively high TPH removal efficiency achieved by the PP–bioaugmentation serial foam application may be attributed to an increase in soil pH caused by the PP and effective infiltration of the remediation agent by foaming. The applied PP foam increased the pH of the acidic soil, thus enhancing microbial activity. The first-order biodegradation rate after PP oxidation was calculated to be 0.068 d−1. Furthermore, 94% of the group of relatively persistent hydrocarbons (C18–C22) was removed by PP–bioaugmentation, as verified by chromatogram peaks. Some physicochemical parameters related to contaminant removal efficiency were also evaluated. The results reveal that PP can degrade soil TPH and significantly enhance the biodegradation rate in unsaturated diesel-contaminated soil when combined with bioaugmentation foam.