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., http://esa.un.org/unpd/wup/Highlights/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

  • Editorial 2018-12-11
  • Chemical fractionation of heavy metals in fine particulate matter and their health risk assessment through inhalation exposure pathway 2018-12-11

    Abstract

    Samples of PM2.5 were collected from an urban area close to a national highway in Agra, India and sequentially extracted into four different fractions: water soluble (F1), reducible (F2), oxidizable (F3) and residual fraction (F4) for chemical fractionation of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni) and lead (Pb). The metals were analyzed by inductively coupled plasma optical emission spectroscopy in each fraction. The average mass concentration of PM2.5 was 93 ± 24 μg m−3.The total concentrations of Cr, Pb, Ni, Co, As and Cd in fine particle were 192 ± 54, 128 ± 25, 108 ± 34, 36 ± 6, 35 ± 5 and 8 ± 2 ng m−3, respectively. Results indicated that Cd and Co had the most bioavailability indexes. Risk Assessment Code and contamination factors were calculated to assess the environmental risk. The present study evaluated the potential Pb hazard to young children using the Integrated Exposure Uptake Biokinetic Model. From the model, the probability density of PbB (blood lead level) revealed that at the prevailing atmospheric concentration, 0.302 children are expected to have PbB concentrations exceeding 10 μg dL−1 and an estimated IQ (intelligence quotient) loss of 1.8 points. The predicted blood Pb levels belong to Group 3 (PbB < 5 μg dL−1). Based on the bioavailable fractions, carcinogenic and non-carcinogenic risks via inhalation exposure were assessed for infants, toddlers, children, males and females. The hazard index for potential toxic metals was 2.50, which was higher than the safe limit (1). However, the combined carcinogenic risk for infants, toddlers, children, males and females was marginally higher than the precautionary criterion (10−6).

  • Effects of steel slag and biochar amendments on CO 2 , CH 4 , and N 2 O flux, and rice productivity in a subtropical Chinese paddy field 2018-12-07

    Abstract

    Steel slag, a by-product of the steel industry, contains high amounts of active iron oxide and silica which can act as an oxidizing agent in agricultural soils. Biochar is a rich source of carbon, and the combined application of biochar and steel slag is assumed to have positive impacts on soil properties as well as plant growth, which are yet to be validated scientifically. We conducted a field experiment for two rice paddies (early and late paddy) to determine the individual and combined effects of steel slag and biochar amendments on CO2, CH4, and N2O emission, and rice productivity in a subtropical paddy field of China. The amendments did not significantly affect rice yield. It was observed that CO2 was the main greenhouse gas emitted from all treatments of both paddies. Steel slag decreased the cumulative CO2 flux in the late paddy. Biochar as well as steel slag + biochar treatment decreased the cumulative CO2 flux in the late paddy and for the complete year (early and late paddy), while steel slag + biochar treatment also decreased the cumulative CH4 flux in the early paddy. The biochar, and steel slag + biochar amendments decreased the global warming potential (GWP). Interestingly, the cumulative annual GWP was lower for the biochar (55,422 kg CO2-eq ha−1), and steel slag + biochar (53,965 kg CO2-eq ha−1) treatments than the control (68,962 kg CO2-eq ha−1). Total GWP per unit yield was lower for the combined application of steel slag + biochar (8951 kg CO2-eq Mg−1 yield) compared to the control (12,805 kg CO2-eq Mg−1 yield). This study suggested that the combined application of steel slag and biochar could be an effective long-term strategy to reduce greenhouse gases emission from paddies without any detrimental effect on the yield.