SEGH Articles

Winner of the Malcolm Brown Outstanding Young Scientist Award

12 August 2016
Gabriel Enge won the Malcolm Brown outstanding young scientist award at the 32nd SEGH International conference in Brussels. He describes his research leading to this award.

I am a research scientist, working on the application of medical isotope metallomics to neurodegenerative diseases. Neurodegenerative diseases are characterized by a progressive loss of neuron function. Illnesses, such as Parkinson’s, Alzheimer’s disease and amyotrophic lateral sclerosis (ALS) are located within the family of neurodegenerative diseases.

Amyotrophic lateral sclerosis was first described in 1869 (Charcot & Joffroy 1869) and is a fatal, predominantly adult-onset neurodegenerative disease that leads to the selective death of motor neurons (Redler & Dokholyan 2012; Rowland & Shneider 2001). This selective death causes progressive muscle paralysis and spasticity, affecting mobility, speech and respiration (Hardiman et al. 2011). Most patients are fully aware of the disease progression, with about half of all affected individuals passing away within 3-5 years of diagnosis, while less than 20% survive more than 5 years (Robberecht & Philips 2013). Approximately 90% of ALS cases are sporadic, and the remaining, familial (Robberecht & Philips 2013). The neuropathology of ALS is staggeringly complex on a subcellular level and includes abnormalities in almost every cellular compartment. It was additionally observed that concentrations of several elements were elevated in the cerebro spinal fluid of ALS patients (Roos et al. 2013), and that mouse models demonstrated specific accumulations of metals (Cu, Zn) in key tissues, such as brain and spinal cord (Li et al. 2006; Tokuda et al. 2007; Tokuda et al. 2013). In spite of our tremendous advances into understanding the disease and its progression in the past 150 years, no diagnostic tools or cures are currently available.

Here at the University of Wollongong, in the Wollongong Isotope Geochronology Laboratory, I have established with my PhD project a new way of looking at the disease. By taking a mouse model of the disease, and applying geochemical analytical techniques of measuring metal concentrations and Cu isotope ratios in tissues, I attempt to gain a more profound understanding of metabolic perturbations that involve metals, in particular Cu. One of the novelty factors of the research includes a time and disease development dependent resolution of changes in metal concentrations and Cu isotope ratios. Future work includes a spatial resolution component using laser ablation methods.

Besides my interest in neurodegenerative diseases, I am also very interested in using metallomics and isotope methods to trace ageing processes in humans, and explore different metabolic ageing processes. Another interest is the continued automation of manual ion-exchange chromatography procedures in order to be able to establish them as part of clinically-diagnostic routines.



Heading: Fun at work with the Neptune Plus MC-ICP-MS



"Let's keep looking in spite of everything. Let us keep searching. It is indeed the best method of finding, and perhaps thanks to our efforts, the verdict we will give such a patient tomorrow will not be the same we must give this man today" - Jean-Martin Charcot (1889).

Charcot's words have been my inspiration since the start of my candidacy and I want to express my deep gratitude for receiving the Malcolm Brown Outstanding Young Scientist Award. I realise that I am not at a stage of my career where I have much to show yet, and therefore I am especially thankful for this indication of support from the community. 



By T. Gabriel Enge, PhD Candidate, School of Earth and Environmental Sciences, University of Wollongong, Australia


J. Charcot and A. Joffrey, Arch. Physiol. Norm. Pathol., 1869, 2, 354-744.

R.L. Redler and N.V. Dokholyan, Prog. Mol. Biol. Trans. Sci., 2012, 107, 215-262

L.P. Rowland and N.A. Schneider, N. Engl. J. Med., 2001, 344, 1688-1700.

O. Hardiman et al., Nat. Rev. Neurol., 2011, 7, 639-649.

W. Robberecht and T. Philips, Nat. Rev. Neurosci., 2013, 14, 248-264.

P.M. Roos et al. Biol. Trace Elem. Res., 2013, 151, 159-170.

Q-X Li et al. Aging Cell, 2006, 5, 153-165.

E. Tokuda et al. Toxicology, 2007, 229, 33-41.

E. Tokuda et al., Neurobiol. Dis., 2013, 54, 308-319.

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.