SEGH Articles

# SEGH 2015: a PhD researchers perspective

15 October 2015
Dan Middleton, a PhD student from the University of Manchester, based at the Centre for Environmental Geochemistry at the British Geological Survey, shares his account of the conference proceedings.

June saw the 31st International Conference of the Society for Environmental Geochemistry and hosted by the State Geological Institute of Dionýz Štúr (SGIDŠ) in Bratislava, Slovak Republic. Dan Middleton, a BUFI funded PhD student from the University of Manchester, based at the Centre for Environmental Geochemistry at the British Geological Survey, shares his account of the conference proceedings.

The coming together of our scientific community to disseminate and share recent and ongoing research findings is, in my opinion, a vital aspect of the development process of our rapidly growing field. Our community in particular is a relatively tight-knit group compared to the core scientific disciplines and one which crosses many boundaries, making networking opportunities such as SEGH 2015 essential for sharing expertise and gaining contacts across broad skill sets. A small community it may be, but nevertheless, more than 80 delegates from 24 countries covering 4 continents descended on the Holiday Inn, Bratislava to fuel a fruitful showcase of projects covering  themes of analytical chemistry, geochemistry, environmental epidemiology and medical geology to name but a few.

Of particular interest to me were the health related topics, as they bridge the gap between measurements of inorganic and organic substances in our environment and how they affect our well-being, both detrimentally and beneficially. This matter was addressed early on by Prof. Stanislav Rapant, hosting the event, in his opening presentation. Using a geochemical baseline survey spanning the whole of the Slovak Republic, Prof Rapant and colleagues from SGIDŠ were able to link concentrations of calcium (Ca) and magnesium (Mg) in drinking water to health statistics of cardiovascular disease (CVD), finding an inverse correlation between exposure and outcome. This research highlighted the first of two take-home messages for me personally – drinking water chemistry is often studied in the light of excess concentrations of chemical elements (I myself gave a presentation on arsenic (As) in UK private water supplies) but of equal importance to human health is ensuring a sufficient supply of the elements that underpin key physiological mechanisms, a point reinforced by Dr Alex Stewart in his talk on the negative health implications of iodine (I) deficiency.

BGS’s very own Dr Mark Cave was in attendance and presented a keynote lecture on findings from a recent project examining the links between London’s soil geochemistry and health related deprivation indices. Mark found that the while unemployment showed the strongest link with detrimental health outcomes, tin (Sn) in soils showed a curious relationship out of the elements studied. This relationship requires further investigation as the causal link between the two variables in not established, however the study demonstrates the power of computer based statistical modelling, in this case the random forest method, in unlocking the secrets of large multivariate datasets.

Another standout talk was that of Dr Munir Zia from the Fauji Fertilizer Company in Pakistan, who presented collaborate research with BGS on potentially harmful elements and dietary minerals in vegetable crops grown in wastewater irrigated soils. Dr Zia used a multitude of techniques to measure both the total and bioaccessible concentrations of analytes in soil and vegetable samples as well as estimating daily intake rates based on literature derived figures and comparing with existing guidance values. For me this highlighted the importance of using an interdisciplinary approach to research problems such as these and addressing the question from a number of angles. This allows us to not only quantify the chemical composition of the media we study, but begin to explore the potential impacts that these compositions may or may not have on our health.

This leads me to the second take-home message of the conference. As geochemists, analytical chemists and environmental scientists, we have an abundance of instrumental techniques at our disposal that enable us to generate quantitative chemical data across a diverse range of samples. What many of us lack in our armoury is the medical and epidemiological expertise to compliment such findings. Environmental Geochemistry and Health is an ever important field and as researchers we need to make sure that both sides of the discipline are maintained. This will be achieved through the coming together of those from both the physical and medical sciences and in particular through the continued engagement of the latter. Furthermore, the personal development of skills outside our respective backgrounds will also aid in forming an adhesive bond between the two factions and promote research that gets closer to answering the question of how our environment impacts our health.

Overall, another worthwhile and insightful meeting that demonstrated the ongoing efforts of our community to engage in diverse research problems using techniques, both analytically and statistically, that are cutting-edge and at the forefront of our field. A big thank you to organisers and delegates alike for making SEGH 2015 a memorable event as we look towards Brussels 2016.

Daniel Middleton, PhD Researcher

University of Manchester and British Geological Survey

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06 July 2020

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09 November 2020

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## Science in theNews

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

• Distribution of metal(loid)s in particle size fraction in urban soil and street dust: influence of population density 2020-01-18

### Abstract

Assessment of street dust is an invaluable approach for monitoring atmospheric pollution. Little information is available on the size distribution of contaminants in street dusts and urban soils, and it is not known how the population density would influence them. This research was carried out to assess the size distribution of trace metal(loid)s in street dust and urban soil, and to understand how population density might influence the size-resolved concentration of metal(loid)s. Three urban areas with a high, medium and low population density and a natural area were selected and urban soil and street dust sampled. They were fractionated into 8 size fractions: 2000–850, 850–180, 180–106, 106–50, 50–20, 20–10, 10–2, and < 2 µm. The concentration of Pb, Zn, Cu, Cd, Cr, Ni, As, and Fe was determined, and enrichment factor and grain size fraction loadings were computed. The results indicated that the concentration of Pb, Zn, Cu, Cd, and Cr was highly size dependent, particularly for particles < 100 µm, especially for street dust. Low concentrations of Ni and As in street dust and urban soil were size and population density independent. Higher size dependency of the metals concentration and the higher degree of elemental enrichment in the street dust fractions than the urban soils indicate higher contribution of human-induced pollution to the dust. Findings also confirm the inevitability of size fractionation when soils or dusts are environmentally assessed, particularly in moderately to highly polluted areas. Otherwise, higher concentrations of certain pollutants in fine-sized particles might be overlooked leading to inappropriate decisions for environmental remediation.

• Soil–plant system and potential human health risk of Chinese cabbage and oregano growing in soils from Mn- and Fe-abandoned mines: microcosm assay 2020-01-17

### Abstract

In Portugal, many abandoned mines are often close to agricultural areas and might be used for plant food cultivation. Soils in the vicinity of two Mn- and Fe-abandoned mines (Ferragudo and Rosalgar, SW of Portugal) were collected to cultivate two different food species (Brassica rapa subsp. pekinensis (Lour.) Hanelt and Origanum vulgare L.). Chemical characterization of the soil–plant system and potential risk of adverse effects for human health posed by plants associated with soil contamination, based on the estimation of hazard quotient (HQ), were assessed in a microcosm assay under greenhouse conditions. In both soils, the average total concentrations of Fe and Mn were above the normal values for soils in the region and their concentration in shoots of both species was very high. Brassica rapa subsp. pekinensis grew better in Ferragudo than in Rosalgar soils, and it behaved as an excluder of Cu, Mn, Fe, S and Zn in both soils. The HQ for Cu, Fe, Mn and Zn in the studied species grown on both soils was lower than unit indicating that its consumption is safe. The high Mn tolerance found in both species might be due in part to the high contents of Fe in the soil available fraction that might contribute to an antagonism effect in the uptake and translocation of Mn. The obtained results emphasize the need of further studies with different food crops before cultivation in the studied soils to assess health risks associated with high metal intake.

• Concentration, fractionation, and ecological risk assessment of heavy metals and phosphorus in surface sediments from lakes in N. Greece 2020-01-13

### Abstract

The presence of phosphorus (P) and heavy metals (HMs) in surface sediments originating from lakes Volvi, Kerkini, and Doirani (N. Greece), as well as their fractionation patterns, were investigated. No statistically significant differences in total P content were observed among the studied lakes, but notable differences were observed among sampling periods. HM contents in all lakes presented a consistent trend, i.e., Mn > Cr > Zn > Pb > Ni > Cu > Cd, while the highest concentrations were recorded in Lake Kerkini. Most of the HMs exceeded probable effect level value indicating a probable biological effect, while Ni in many cases even exceeded threshold effects level, suggesting severe toxic effects. P was dominantly bound to metal oxides, while a significant shift toward the labile fractions was observed during the spring period. The sum of potentially bioavailable HM fractions followed a downward trend of Mn > Cr > Pb > Zn > Cu > Ni > Cd for most lakes. The geoaccumulation index Igeo values of Cr, Cu, Mn, Ni, and Zn in all lakes characterized the sediments as “unpolluted,” while many sediments in lakes Volvi and Kerkini were characterized as “moderately to heavily polluted” with regard to Cd. The descending order of potential ecological risk $$E_{\text{r}}^{i}$$ was Cd > Pb > Cu > Ni > Cr > Zn > Mn for all the studied lakes. Ni and Cr presented the highest toxic risk index values in all lake sediments. Finally, the role of mineralogical divergences among lake sediments on the contamination degree was signified.