Abstract
Establishing geochemical background concentrations to distinguish the natural background from anthropogenic concentrations of heavy metals in sediments and soils is necessary to develop guidelines for environmental legislation. Due to the fact that the background concentrations strongly depend on geological characteristics such as mineral composition, grain size distribution and organic matter content, several normalization methods have been developed. Empirical (geochemical), theoretical (statistical) and integrated methods (combining both empirical and theoretical methods) are the main approaches described in literature for determination of geochemical background concentrations. In this review paper, the different approaches as well as the main normalization methods for heavy metal concentrations in sediments and soils will be discussed. Both geochemical background concentrations and added risk level (maximum permissible addition) should be taken into account for setting up legal threshold limits. Moreover, different approaches to evaluate the pollution status of heavy metals in sediments and soils, from Sediment/Soil Quality Guidelines to quantitative indices (Geo-accumulation Index-Igeo, Enrichment Factor-EF, Pollution Load Index-PLI and Risk assessment Code-RAC) will be presented. Although guidelines to establish whether a sediment or soil is polluted or not are generally only related to total metal concentrations, the available/reactive pool i.e., availability/reactivity of metals should be taken into account for sediment/soil pollution assessment.
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References
Abrahim GMS, Parker RJ (2008) Assessment of heavy metal enrichment factors and the degree of contamination in marine sediments from Tamaki Estuary, Auckland, New Zealand. Environ Monit Assess 136:227–238
Ackermann F (1980) A procedure for correcting the grain size effect in heavy metal analyses of estuarine and coastal sediments. Environ Technol Lett 1:518–527
Adokoh CK, Obodai EA, Essumang DK, Serfor-Armah Y, Nyarko BJB, Asabere-Ameyaw A (2011) Statistical evaluation of environmental contamination, distribution and source assessment of heavy metals (aluminum, arsenic, cadmium, and mercury) in some lagoons and an estuary along the coastal belt of Ghana. Arch Environ Contam Toxicol 61(3):389–400
Alexander DE, Fairbridge WR (1999) Encyclopedia of environmental science. Kluwer Academic Publishers, Dordrecht, The Netherlands
Alloway BJ, Ayres DC (1997) Chemical principles of environmental pollution. Blackie Academic and Professional, London
Aloupi M, Angelidis MO (2001) Geochemistry of natural and anthropogenic metals in the Coastal sediments of the island of Lesvos, Aegean Sea. Environ Pollut 113(2):211–219
Baeyens W, Panutrakul S, Elskens M, Leermakers M, Navez J, Monteny F (1991) Geochemical processes in muddy and sandy tidal sediments. Geo Lett 11:188–193
Batley GE (2012) “Heavy metal”—a useful term. Integr Environ Assess Manag 8(2):215
Bing H, Wu Y, Sun Z, Yao S (2011) Historical trends of heavy metal contamination and their sources in lacustrine sediment from Xijiu Lake, Taihu Lake Catchment, China. J Environ Sci 23(10):1671–1678
Bini C, Sartori G, Wahsha M, Fontana S (2011) Background levels of trace elements and soil geochemistry at regional level in NE Italy. J Geochem Explor 109(1–3):125–133
Birkeland PW (1999) Soils and geomorphology, 3rd edn. Oxford University Press, New York
Bolviken B, Bogen J, Dematriades A, Devos W, Ebbing J, Hindel R, Langedal M, Locutura J, O’Connor P, Ottensen RT, Pulkkinen E, Salminen R, Schermann P, Swennen R, Van der Sluys J, Volden T (1996) Regional geochemical mapping of Western Europe towards the year 2000. J Geochem Expl 56:141–166
Bordas F, Bourg A (2001) Effect of solid/liquid ratio on the remobilization of Cu, Pb, and Zn from polluted river sediment. Water Air Soil Pollut 128:391–400
Brady NC, Weil RR (1999) The nature and properties of soils, 20th edn. Prentice Hall, Englewood Cliffs
Burton JGA (2002) Sediment quality criteria in use around the world. Limnology 3(2):65–76
Caeiro S, Costa MH, Ramos TB, Fernandes F, Silveira N, Coimbra AP, Medeiros G (2005) Assessing heavy metal contamination in Sado Estuary sediment: an index analysis approach. Ecol Indic 5(2):151–169
Caeiro S, Costa MH, Del Valls A, Repolho T, Gonçalves M, Mosca A, Coimbra AP (2009) Ecological risk assessment of sediment management areas: application to Sado Estuary, Portugal. Ecotoxicology 18(8):1165–1175
Cappuyns V (2004) Heavy metal behavior in overbank sediments and associated soils. Dissertation, KULeuven, Belgium
Cappuyns V (2012) A critical evaluation of single extractions from the SMT program to determine trace element mobility in sediments. Appl Environ Soil Sci 2012:1–15
Carlon C (2007) Derivation methods of soil screening values in Europe. A review and evaluation of national procedures towards harmonisation. European Commission, Joint Research Centre, Ispra, EUR 22805-EN
CCME (Canadian Council of Ministers of the Environment) (2002) Canadian Sediment Quality Guidelines for the protection of aquatic life. http://www.ecy.wa.gov/programs/eap/psamp/BoundaryBay/PSAMP-BBAMP%20documents/Canadian%20guidelines%20for%20water%20quality/SedimentProtAquaticLifeSummaryTables(en).pdf. Accessed 20 Sept 2012
CCME (Canadian Council of Ministers of the Environment) (2007) Canadian soil quality guidelines for the protection of environmental and human health
Chapman PM (2007) Determining when contamination is pollution—weight of evidence determinations for sediments and effluents. Environ Int 33(4):492–501
Chapman PM (2012) ‘‘Heavy metal’’—cacophony, not symphony. Integr Environ Assess Manag 8(2):216
Chapman PM, Hyland J, Ingersoll C, Carr S, Engle V, Green R, Hameedi J, Harmon M (1997) General guidelines for using the sediment quality triad. Mar Pollut Bull 34:368–372
Cheevaporn V, San Diego-McGlone ML (1997) Aluminium normalization of heavy metal data from estuarine and coastal sediments of the Gulf of Thailand. Int J Sci Tech 2(2):37–46
Christophoridis C, Dedepsidis D, Fytianos K (2009) Occurrence and distribution of selected heavy metals in the surface sediments of Thermaikos Gulf, N. Greece. Assessment using pollution indicators. J Hazard Mater 168(2–3):1082–1091
Church SE (1993) Geochemical and lead-isotope data from stream and lake sediments, and cores from the upper Arkansas River drainage: effects of mining at Leadville Colorado on heavy metal concentration in the Arkansas River, United States Geological survey, Open File Report 93–534
Church SE, Alpers CN, Vaughn RB, Briggs PH and Slotton DG (1999) Use of lead isotopes as natural tracers of metal contamination. In: Plumlee GS and Logsdon MJ (eds) The environmental geochemistry of mineral deposits, part A. Processes, techniques, and health issues. Rev Econ Geol 6A, Society of Economic Geologists Littleton, pp 567–583
Covelli S, Fontolan G (1997) Application of a normalization procedure in determining regional geochemical baselines. Environ Geol 30(1/2):34–45
De Saedeleer V, Cappuyns V, De Cooman W, Swennen R (2010) Influence of major elements on heavy metal composition of river sediments. Geol Belg 3:257–268
De Temmerman LDE, Vanongeval L, Boon W, Hoenig M, Geypens M (2003) Heavy metal content of arable soils in northern Belgium. Water Air Soil Pollut 148:61–76
De Vos W, Ebbing J, Hindel R, Schalich J, Swennen R, Van Keer I (1996) Geochemical mapping based on overbank sediments in the heavily industrialized border area of Belgium, Germanny and the Netherlands. J Geochem Expl 56:91–104
Desaules A (2012) Critical evaluation of soil contamination assessment methods for trace metals. Sci Total Environ 426:120–131
Duffus JH (on behalf of IUPAC, Chemistry and Human Health Division, Clinical Chemistry Section, Commission on Toxicology) (2002) “Heavy metals”—a meaningless term?. Pure Appl Chem 74:793–807
Duzgoren-Aydn NS, Weiss AL (2008) Use and abuse of Pb-isotope fingerprinting technique and GIS mapping data to assess lead in environmental studies. Environ Geochem Health 30(6):577–588
Filgueiras AV, Lavilla I, Bendicho C (2002) Chemical sequential extraction for metal partitioning in environmental solid samples. J Environ Monitor 4(6):823–857
Forstner U, Ahlf W, Calmano W (1989) Studies on the transfer of heavy metals between sedimentary phases with a multi-chamber device: combined effects of salinity and redox variation. Mar Chem 28:145–158
Gałuszka A (2007) A review of geochemical background concepts and an example using data from Poland. Environ Geol 52(5):861–870
Gałuszka A, Migaszewski ZM (2011) Geochemical background–an environmental perspective. Miner 42(1):7–17
Garrett RG (1991) The management, analysis and display of exploration geochemical data. Exploration geochemistry workshop, Ottawa Geological Survey of Canada, Open File 2390
Garrett RG and Grunsky EC (2011) Geochemical background—what it is and how it varies. In: Proceedings and recommendations from the Workshop on the role of geochemical data in environmental and human health risk assessment, Halifax, 2010, (ed) Rencz AN and Kettles IM, Geological Survey of Canada, Open File 6645, 1 CD-ROM
Görlich K, Görlich E, Tomala K, Hrynkiewicz A, Hung PQ (1989) 57Fe Mossabauer study of a sediment column in the Gdansk basin, Baltic sea: palaeoenvironmental application. Mar Geo 88:49–69
Grant A, Middleton R (1990) An assessment of metal contamination of sediments in the Humber estuary, U K. Estuar Coast Shelf Sci 31:71–85
Grousset FE, Quetel CR, Thomas B, Donard OFX, Lambert CE, Quillard F, Monaco A (1995) Anthropogenic vs. lithogenic origins of trace elements (As, Cd, Pb, Rb, Sb, Sc, Sn, Zn) in water column particles: northwestern Mediterranean Sea. Mar Chem 48:291–310
Hawkes HE, Webb JS (1962) Geochemistry in mineral exploration. Harper, New York
Herut B and Sandler A (2006) Normalization methods for pollutants in Marine sediments: review and recommendations for the Mediterranean Israel Oceanographic and Limnological Research, IOLR Report, pp 1–23
Herut B, Hornung H, Kress N, Krom MD, Shirav M (1995) Trace metals in sediments at the lower reaches of Mediterranean coastal rivers, Israel. Wat Sci Tech 32:239–246
Hlavay J, Prohaska T, Weisz M, Wenzel WW, Stingeder GJ (2004) Determination of trace elements bound to soils and sediment fractions (IUPAC Technical Report). Pure App Chem 76(2):415–442
Ho HH, Swennen R, Van Damme A (2010) Distribution and contamination status of heavy metals in estuarine sediments near Cua ong harbor, Ha Long bay, Vietnam. Geol Belg 13:37–47
Ho HH, Swennen R, Cappuyns V, Vassilieva E, Tran TV (2012) Necessity of normalization to aluminum to assess the contamination by heavy metals and arsenic in sediments near Haiphong Harbor, Vietnam. J Asian Earth Sci 56:229–239
Hoefs J (2009) Stable Isotope geochemistry. Springer, New York
Holdgate MW (1979) A perspective of environmental pollution. Cambridge University Press, Cambridge
Hong-gui D, Teng-feng G, Ming-hui L, Xu D (2012) Comprehensive assessment model on heavy metal pollution in soil. Int J Electrochem Sci 7:5286–5296
Horowitz J (1985) A primer on trace metal- sediment chemistry. United States Geological survey water-supply paper, pp 72
Injuk J, Van Grieken R, De Leeuw G (1998) Deposition of atmospheric trace elements into the North sea: coastal, ship, platform measurements and model predictions. Atmos Environ 32(17):3011–3025
Izbicki JA, Ball JW, Bullen TD, Sutley SJ (2008) Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA. Appl Geochem 23:1325–1352
Jan E, Joanna Z, Szymon U, Cees L (2002) Normalisation as a tool for environmental impact studies: the Gulf of Gdansk as a case study. Baltica 15:49–62
Jokšas K, Stakėnienė R, Galkus A, Lagunavičienė L (2008) Metals in bottom sediments of Šventoji Port area (Lithuania). Geology 50(3):143–155
Jumbe A, Nandini N (2009) Heavy metals analysis and sediment quality values in urban Lakes. Am J Environ Sci 5(6):678–687
Kersten M, Förstner U (1991) Geochemical characterization of pollutants mobility in cohesive sediments. Geo Lett 11:184–197
Loring DH (1990) Lithium—a new approach for the granulometric noramalization of trace metal data. Mar Chem 29:155–168
Loring DH, Rantala RTT (1992) Manual for the geochemical analyses of marine sediments and suspended particulate matter. Earth Sci Rev 32:235–283
Loska K, Cebula J, Pelczar J, Wiechula D, Kwapulinski J (1997) Use of Enrichment, and Contamination factors together with Geoaccumulation indexes to evaluate the content of Cd, Cu, and Ni in the Rybnik water reservoir in Poland. Water Air Soil Pollut 93:347–365
Luthy RG, Allen-King RM, Brown SL, Dzombak DA, Fendorf SE, Giesy JP, Hughes JB, Louma SN, Malone LA, Menzie CA, Roberts SM, Ruby GMV, Schultz TW, Smets KBF (2003) Bioavailability of contaminants in soils and sediments: process, tools and applications. The National Academies Press, Washington, p 433
Manceau A, Matthew AM, Nobumichi T (2002) Quantitative speciation of heavy metals in soils and sediments by synchrotron X-ray techniques. Rev Miner Geochem 49:341–428
Massas I, Ehaliotis C, Kalivas D, Panagopoulou G (2010) Concentrations and availability indicators of soil heavy metals; the case of children’s playgrounds in the city of Athens (Greece). Water Air Soil Pollut 212(1–4):51–63
Matschullat J, Ottenstein R, Reimann C (2000) Geochemical background—can we calculate it? Environ Geol 39(9):990–1000
Morse JW, Millero FJ, Cornwell JC, Rickard D (1987) The chemistry of the hydrogen sulfide and iron sulfide systems in natural waters. Earth Sci Rev 24:1–42
Müller G (1969) Index of geoaccumulation in sediments of the Rhine River. Geol J 2:109–118
Muller-Karulis B, Poikane R, Seglins V (2003) Heavy metals in the Ventspils Harbour: normalization based on a multi-parameter dataset. Environ Geol 43:445–456
Pacyna JM, Pacyna EG (2001) An assessment of global and regional emissions of trace metals to the atmosphere from anthropogenic sources worldwide. Environ Rev 9(4):269–298
Paikaray S (2012) Environmental hazards of arsenic associated with black shales: a review on geochemistry, enrichment and leaching mechanism. Rev Environ Sci Biotechnol 11:289–303
Passos EA, Alves JPH, Garcia CAB, Costa AC (2011) Metal fractionation in sediments of the Sergipe River, northeast, Brazil. J Braz Chem Soc 22(5):828–835
Peirson DH, Cawse PA (1979) Trace elements in the atmosphere. Phil Trans R Soc Lond B288:41–49
Peltier E, Dahl AL, Gaillard JF (2005) Metal speciation in anoxic sediments: when sulfides can be construed as oxides. Environ Sci Tech 39(1):311–316
Pérez-Sirvent C, Martínez-Sánchez MJ, García-Lorenzo ML, Molina J, Tudela ML (2009) Geochemical background levels of zinc, cadmium and mercury in anthropically influenced soils located in a semi-arid zone (SE, Spain). Geoderma 148(3–4):307–317
Perin G, Craboledda L, Lucchese M, Cirillo R, Dotta L, Zanetta ML, Oro AA (1985) Heavy metal speciation in the sediments of Northern Adriatic Sea. A new approach for environmental toxicity determination. In: Lakkas TD (ed) Heavy metals in the environment, vol 2. CEP Consultants, Edinburg
Pfannkuch H (1990) Elsevier’s dictionary of environmental hydrogeology. Elsevier, Amsterdam
Porteous A (1996) Dictionary of environmental science and technology, 2nd edn. Wiley, Chichester
Praveena SM, Radojevic M, Abdullah MH (2007) The Assessment of mangrove sediment quality in Mengkabong Lagoon: an index analysis approach. Int J Environ Sci Educ 2(3):60–68
Prohic E, Miko S, Peh Z (1995) Nomarlisation and trace element contamination of soils in a Karstic Polje-An example from the Sinjsko Polje, Croatia. Geol Croat 48(1):67–86
Qi S, Leipe T, Rueckert P, Di Z, Harff J (2010) Geochemical sources, deposition and enrichment of heavy metals in short sediment cores from the Pearl River Estuary, Southern China. J Mar Syst 82:S28–S42
Ramos-Miras JJ, Roca-Perez L, Guzmán-Palomino M, Boluda R, Gil C (2011) Background levels and baseline values of available heavy metals in Mediterranean greenhouse soils (Spain). J Geochem Explor 110(2):186–192
Rao CRM, Sahuquillo A, Lopez Sanchez JF (2008) A review of the different methods applied in environmental geochemistry for single and sequential extraction of trace elements in soils and related materials. Water Air Soil Pollut 189:291–333
Rath P, Panda UC, Bhatta D, Sahu KC (2009) Use of sequential leaching, mineralogy, morphology and multivariate statistical technique for quantifying metal pollution in highly polluted aquatic sediments-a case study: Brahmani and Nandira Rivers, India. J Hazard Mater 163:632–644
Reimann C, De Caritat P (2005) Distinguishing between natural and anthropogenic sources for elements in the environment: regional geochemical surveys versus enrichment factors. Sci Total Environ 337:91–107
Reimann C, Garrett RG (2005) Geochemical background–concept and reality. Sci Total Environ 350(1–3):12–27
Reimann C, Filzmoser P, Garrett RG (2005) Background and threshold: critical comparison of methods of determination. Sci Total Environ 346(1–3):1–16
Rencz AN, Garrett RG, Adcock SW, Spirito WA, Bonham-Carter GF (2006) Geochemical background in soil and till. Geological Survey of Canada, Open File 6645, 1 CD-ROM
Roca N, Pazos MS, Bech J (2012) Background levels of potentially toxic elements in soils: a case study in Catamarca (a semi—arid region in Argentina). Catena 92:55–66
Romano S, Mugnai C, Giuliani S, Nguyen HC, Bellucci L, Dang HN, Capodaglio G, Frignani M (2012) Metals in sediment cores from nine coastal lagoons in Central Vietnam. Am J Environ Sci 8(2):130–142
Roussiez V, Ludwig W, Probst JL, Monaco A (2005) Background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean): an approach based on 133Cs normalization and lead isotope measurements. Environ Pollut 138(1):167–177
Rubio B, Nombela MA, Vilas F (2000) Geochemistry of major and trace elements in sediments of the Ria de Vigo (NW Spain): an assessment of metal pollution. Mar Pollut Bull 40(11):968–980
Saby NP, Thioulouse J, Jolivet CC, Ratié C, Boulonne L, Bispo A, Arrouays D (2009) Multivariate analysis of the spatial patterns of 8 trace elements using the French soil monitoring network data. Sci Total Environ 407(21):5644–5652
Saby NP, Marchant BP, Lark RM, Jolivet CC, Arrouays D (2011) Robust geostatistical prediction of trace elements across France. Geoderma 162(3–4):303–311
Sahuquillo A (2003) Overview of the use of leaching/extraction tests for risk assessment of trace metals in contaminated soils and sediments. Trends Anal Chem 22(3):152–159
Salminen R, Tarvainen T, Demetriades A, Duris M, Fordyce FM, Gregorauskiene V, Kahelin H, Kivisilla J, Klaver G, Klein H, Larson JO, Lis J, Locutura J, Marsina K, Mjartanova H, Mouvet C, O’Connor P, Odor L, Ottonello G, Paukola T, Plant JA, Reimann C, Schermann O, Siewers U, Steenfelt A, Van der Sluys J, De Vivo B, Williams L (1998) FOREGS geochemical mapping field manual. Geological Survey of Finland, Espoo, Guide 47, p 36
Schiff K, Weisberg SB (1999) Iron as a reference element for determining trace metal enrichment in Southern California coastal shelf sediments. Mar Environ Res 48(2):161–176
SDD (1976) Development of a water quality index (Report AR3). Scottish Development Department, Edinburgh
Sekabira K, Origa HO, Basamba TA, Mutumba G, Kakudidi E (2010) Assessment of heavy metal pollution in the urban stream sediments and its tributaries. Int J Environ Sci Tech 7(3):435–446
Shin PK, Lam WK (2001) Development of a marine sediment pollution index. Environ Pollut 113(3):281–291
Singh M, Müller G, Singh IB (2002) Heavy metals in freshly deposited stream sediments of rivers associated with urbanisation of the Ganga plain, India. Water, Air and Soil Pollut 141:35–54
Soto-Jiménez M, Páez-Osuna F (2001) Distribution and normalization of heavy metal concentrations in mangrove and lagoonal sediments from Mazatlán Harbor (SE Gulf of California). Estuar Coast Shelf Sci 53(3):259–274
Spijker J (2012) The Dutch soil type correction: an alternative approach. Natl. Inst. Public Health Environ. (RIVM report 607711005/2012)
Spijker J, Mol G, Posthuma L (2011) Regional ecotoxicological hazards associated with anthropogenic enrichment of heavy metals. Environ Geochem Health 33(4):409–426
Struijs J, Van de Meent D, Peijnenburg WJGM, Van den Hoop MAGT, Crommentuijn T (1997) Added risk approach to derive maximum permissible concentrations for heavy metals: how to take natural background levels into account. Ecotoxicol Environ Saf 37:112–118
Swennen R, Van der Sluys J (1998) Zn, Pb, Cu and As distribution patterns in overbank and medium-order stream sediment samples: their use in exploration and Environmental geochemistry. J Geochem Explor 65(1):27–45
Tack FMG, Verloo MG, Vanmechelen L, Van Ranst E (1997) Baseline concentration levels of trace elements as a function of clay and organic carbon contents in soils in Flanders (Belgium). Sci Total Environ 201(2):113–123
Tessier A, Campbell PGC and Bisson M (1979) Sequential Extraction Procedure for the Speciation of Particulate Trace Metals. Analyt Chem 51(7):844–850
Tomlinson DJ, Wilson JG, Harris CR, Jeffrey DW (1980) Problems in the assessment of heavy metal levels in estuaries and the formation of a pollution index. Helgoland Mar Res 33(1–4):566–575
Tume P, Bech J, Longan L, Tume L, Reverter F, Sepulveda B (2006) Trace elements in natural surface soils in Sant Climent (Catalonia, Spain). Ecol Eng 27(2):145–152
UNEP/IOC/IAEA (1995) Manual for the geochemical analyses of marine sediment and suspended particular matter. Reference methods for marine pollution studies No 63, UNEP 1995
Ungaro F, Ragazzi F, Cappellin R, Giandon P (2008) Arsenic concentration in the soils of the Brenta Plain (Northern Italy): mapping the probability of exceeding contamination thresholds. J Geochem Explor 96(2–3):117–131
Ure AM (1996) Single extraction schemes for soil analysis and related applications. Sci Total Environ 178(1–3):3–10
US EPA (United States Environmental protection Agency) (2000) EPA’s Terms of Environment
van der Weijden CH (2002) Pitfalls of normalization of marine geochemical data using a common divisor. Mar Geol 184:167–187
van Hullebusch ED, Lens PNL, Tabak HH (2005) Developments in bioremediation of soils and sediments polluted with metals and radionuclides. 3. Influence of chemical speciation and bioavailability on contaminants immobilization/mobilization bio-processes. Rev Environ Sci Biotechnol 4(3):185–212
VLAREBO (2006) Vlaams reglement betreffende de bodemsanering. Decree on Soil remediation and Soil protection; ratified by the Flemish government on 27 October 2006
Woitke P, Wellmitz J, Helm D, Kube P, Lepom P, Litheraty P (2003) Analysis and assessment of heavy metal pollution in suspended solids and sediments of the river Danube. Chemosphere 51:633–642
Wong CSC, Li XD (2004) Pb contamination and isotopic composition of urban soils in Hong Kong. Sci Total Environ 319(1–3):185–195
Zhao FJ, McGrath SP, Merrington G (2007) Estimates of ambient background concentrations of trace metals in soils for risk assessment. Environ Pollut 148(1–3):221–229
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Dung, T.T.T., Cappuyns, V., Swennen, R. et al. From geochemical background determination to pollution assessment of heavy metals in sediments and soils. Rev Environ Sci Biotechnol 12, 335–353 (2013). https://doi.org/10.1007/s11157-013-9315-1
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DOI: https://doi.org/10.1007/s11157-013-9315-1