SEGH Articles

Urban Geochemical Mapping by the Geochemistry Expert Group of EuroGeoSurveys

25 March 2016
Given the fact that by 2050 more than 80% of the European population will be living in cities (United Nations, 2014), the quality of the urban environment is becoming an important issue in the 21st century.

Given the fact that by 2050 more than 80% of the European population will be living in cities (United Nations, 2014), the quality of the urban environment is becoming an important issue in the 21st century. Ever since the industrial revolution, with a peak after the Second World War, the urban environment has been contaminated with many toxic elements and compounds, which are being emitted by a wide variety of human activities (industry, traffic, domestic heating, coal and oil combustion, incineration, construction activities, etc.),  and often accumulate in urban soil.

Since, the 1970s a conscious attempt is being made in many countries to develop industrial estates outside the residential, commercial, and recreational parts of cities. Within the urban structure remain, however, the brownfield sites, and the enormous problem of their redevelopment in order to reduce the pressure on greenfield sites.  As many health-related problems are linked to the state of the urban environment, the European citizens want to know the geochemistry of the land their houses are built on. Moreover, it is very important that the chemical quality of soil in public places, such as schoolyards, parks, playgrounds, kindergartens, recreation areas, and workplaces is known. Estate agents need to know the quality of the land they are marketing, and insurance brokers the potential risks to their customers.

The Geochemistry Expert Group of EuroGeoSurveys realising that knowledge about soil contamination, geochemical background concentrations, and detailed spatial element distribution is becoming a key issue in urban planning initiated in 2008 an Urban Geochemistry project with the acronym URGE.  The first part was the compilation of all hitherto knowledge and its publication in a full-colour textbook “Mapping the Chemical Environment of Urban Areas” (Johnson et al., 2011):

The first part of the textbook covers more general aspects of urban chemical mapping, with an overview of current practice, and reviews of different features of the component methodologies (chemical analysis, quality control, data interpretation and presentation, risk assessment, etc.). The second part includes a number of case studies from different urban areas, principally from Europe, but with some contributions from North America, Africa and Asia.  Many of the chapters discuss the potential impact on human health and describe the multi-disciplinary effort, usually supported by legislation, required to deal with the legacy of contamination found in many urban areas.

Apart from the publication of the textbook, different urban geochemical projects were carried out in different European cities, and the results are in the process of being published in a Special Issue of the Journal of Geochemical Exploration on Urban Geochemical Mapping, thus ending the first phase of the URGE project.

One of the results of the textbook and the urban geochemical surveys that were carried out in Europe is that the comparability between investigations and results from different European cities, the European overview, is missing. Thus, a second phase of the URGE project is in the process of being initiated. The suggested project aims at advising the city administration how such studies should be carried out, and how the data are best stored, evaluated and presented.  Furthermore, a directly comparable database shall be built for a number of European reference cities (N=15-25), participating in the proposed project.  For this purpose, a detailed manual for sampling topsoil in urban areas has been written (Demetriades and Birke, 2015a):

 

As there was a demand for a comprehensive Urban Geochemical Mapping Manual by the EU COST  Sub-Urban project (http://www.sub-urban.eu/), the EuroGeoSurveys’ Geochemistry Expert Group was commissioned to write it (Demetriades and Birke, 2015b) as part of WG 2.6 “Geochemistry” (http://sub-urban.squarespace.com/new-index-1/#geotechnical-modelling-hazards-wg-25):

 

 

by EurGeol Alecos Demetriades

former Director of the Division of Geochemistry and Environment,

Hellenic Institute of Geology and Mineral Exploration, Athens


References

Demetriades, A., Birke, M., 2015a.  Urban Topsoil Geochemical Mapping Manual (URGE II).  EuroGeoSurveys, Brussels, 52 pp., http://www.eurogeosurveys.org/wp-content/uploads/2015/06/EGS_Urban_Topsoil_Geochemical_Mapping_Manual_URGE_II_HR_version.pdf.

Demetriades, A., Birke, M., 2015b.  Urban Geochemical Mapping Manual:  Sampling, Sample preparation, Laboratory analysis, Quality control check, Statistical processing and Map plotting.  EuroGeoSurveys, Brussels, 162 pp., http://www.eurogeosurveys.org/wp-content/uploads/2015/10/Urban_Geochemical_Mapping_Manual.pdf.

Johnson, C.C., Demetriades, A., Locutura, J., Ottesen, R.T. (Editors), 2011.  Mapping the chemical environment of urban areas.  Wiley-Blackwell, John Wiley & Sons Ltd., Chichester, U.K., 616 pp., http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0470747242.html.

United Nations, 2014.  World Urbanization Prospects:  The 2014 Revision, Highlights (ST/ESA/SER.A/352). United Nations, Department of Economic and Social Affairs, Population Division, New York, 32 pp., https://selectra.co.uk/sites/selectra.co.uk/files/pdf/WUP2014-Highlights.pdf

 

As there was a demand for a comprehensive Urban Geochemical Mapping Manual by the EU COST  Sub-Urban project (http://www.sub-urban.eu/), the EuroGeoSurveys’ Geochemistry Expert Group was commissioned to write it (Demetriades and Birke, 2015b) as part of WG 2.6 “Geochemistry” (http://sub-urban.squarespace.com/new-index-1/#geotechnical-modelling-hazards-wg-25):

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

  • Ecological impact of the antibiotic ciprofloxacin on microbial community of aerobic activated sludge 2019-08-16

    Abstract

    This study investigated the effects and fate of the antibiotic ciprofloxacin (CIP) at environmentally relevant levels (50–500 µg/L) in activated sludge (AS) microbial communities under aerobic conditions. Exposure to 500 µg/L of CIP decreased species diversity by about 20% and significantly altered the phylogenetic structure of AS communities compared to those of control communities (no CIP exposure), while there were no significant changes upon exposure to 50 µg/L of CIP. Analysis of community composition revealed that exposure to 500 µg/L of CIP significantly reduced the relative abundance of Rhodobacteraceae and Nakamurellaceae by more than tenfold. These species frequently occur in AS communities across many full-scale wastewater treatment plants and are involved in key ecosystem functions (i.e., organic matter and nitrogen removal). Our analyses showed that 50–500 µg/L CIP was poorly removed in AS (about 20% removal), implying that the majority of CIP from AS processes may be released with either their effluents or waste sludge. We therefore strongly recommend further research on CIP residuals and/or post-treatment processes (e.g., anaerobic digestion) for waste streams that may cause ecological risks in receiving water bodies.

  • Source and background threshold values of potentially toxic elements in soils by multivariate statistics and GIS-based mapping: a high density sampling survey in the Parauapebas basin, Brazilian Amazon 2019-08-10

    Abstract

    A high-density regional-scale soil geochemical survey comprising 727 samples (one sample per each 5 × 5 km grid) was carried out in the Parauapebas sub-basin of the Brazilian Amazonia, under the Itacaiúnas Basin Geochemical Mapping and Background Project. Samples were taken from two depths at each site: surface soil, 0–20 cm and deep soil, 30–50 cm. The ground and sieved (< 75 µm) fraction was digested using aqua regia and analyzed for 51 elements by inductively coupled plasma mass spectrometry (ICPMS). All data were used here, but the principal focus was on the potential toxic elements (PTEs) and Fe and Mn to evaluate the spatial distribution patterns and to establish their geochemical background concentrations in soils. Geochemical maps as well as principal component analysis (PCA) show that the distribution patterns of the elements are very similar between surface and deep soils. The PCA, applied on clr-transformed data, identified four major associations: Fe–Ti–V–Sc–Cu–Cr–Ni (Gp-1); Zr–Hf–U–Nb–Th–Al–P–Mo–Ga (Gp-2); K–Na–Ca–Mg–Ba–Rb–Sr (Gp-3); and La–Ce–Co–Mn–Y–Zn–Cd (Gp-4). Moreover, the distribution patterns of elements varied significantly among the three major geological domains. The whole data indicate a strong imprint of local geological setting in the geochemical associations and point to a dominant geogenic origin for the analyzed elements. Copper and Fe in Gp-1 were enriched in the Carajás basin and are associated with metavolcanic rocks and banded-iron formations, respectively. However, the spatial distribution of Cu is also highly influenced by two hydrothermal mineralized copper belts. Ni–Cr in Gp-1 are highly correlated and spatially associated with mafic and ultramafic units. The Gp-2 is partially composed of high field strength elements (Zr, Hf, Nb, U, Th) that could be linked to occurrences of A-type Neoarchean granites. The Gp-3 elements are mobile elements which are commonly found in feldspars and other rock-forming minerals being liberated by chemical weathering. The background threshold values (BTV) were estimated separately for surface and deep soils using different methods. The ‘75th percentile’, which commonly used for the estimation of the quality reference values (QRVs) following the Brazilian regulation, gave more restrictive or conservative (low) BTVs, while the ‘MMAD’ was more realistic to define high BTVs that can better represent the so-called mineralized/normal background. Compared with CONAMA Resolution (No. 420/2009), the conservative BTVs of most of the toxic elements were below the prevention limits (PV), except Cu, but when the high BTVs are considered, Cu, Co, Cr and Ni exceeded the PV limits. The degree of contamination (Cdeg), based on the conservative BTVs, indicates low contamination, except in the Carajás basin, which shows many anomalies and had high contamination mainly from Cu, Cr and Ni, but this is similar between surface and deep soils indicating that the observed high anomalies are strictly related to geogenic control. This is supported when the Cdeg is calculated using the high BTVs, which indicates low contamination. This suggests that the use of only conservative BTVs for the entire region might overestimate the significance of anthropogenic contamination; thus, we suggest the use of high BTVs for effective assessment of soil contamination in this region. The methodology and results of this study may help developing strategies for geochemical mapping in other Carajás soils or in other Amazonian soils with similar characteristics.

  • Uptake of Cd, Pb, and Ni by Origanum syriacum produced in Lebanon 2019-08-06

    Abstract

    Trace metals are found naturally in soil. However, the increase in industrial and agricultural polluting activities has increased trace metal contamination and raised high concerns in the public health sector. The study was conducted on Origanum syriacum, one of the most consumed herbs in the Middle East, and was divided into three parts. (1) Pot experiment: to study the effect of Cd, Pb, or Ni levels in soil on their uptake by O. syriacum. (2) Field samples: collected from major agricultural regions in Lebanon to analyze Cd, Pb, and Ni concentrations in soil and leaves. (3) Sale outlets samples: to measure the levels of Cd, Pb, and Ni in O. syriacum tissues in the market. Results showed that there was a positive correlation between levels of Cd, Pb, and Ni in soil and those in O. syriacum tissues. None of the field samples contained Pb or Ni that exceeded the maximum allowable limits (MAL). Three samples collected from heavily poultry-manured soil contained Cd higher than the MAL. Samples collected from sale outlets did not exceed the MAL for Ni but two exceeded the MAL for Cd and one for Pb. Trace metal contamination is not a major concern in O. syriacum produced in Lebanon. Only one mixture sample from a sale outlet was higher in Pb than the MAL and three samples from heavily manured fields exceeded the MAL for Cd.