Heavy metals fractionation and multivariate statistical techniques to evaluate the environmental risk in soils of Huelva Township (SW Iberian Peninsula)

Abstract The city of Huelva and surrounding areas are affected by several sources of pollution such as acid mine drainage, industrial complexes, urban wastes and agriculture activities that could pose an important environmental risk. For this reason, the modified BCR (three steps) sequential extraction method was applied to evaluate the mobility and bioavailability of the trace elements in 25 representative samples of the study area. The operational scheme of the BCR was classified into three steps: water/acid soluble fraction, reducible and oxidisable fraction. The mobility sequence based on the sum of three first phases was: Cu (82.01%) > Zn (71.14%) > Cd (68.35%) > Ni (50.44%) > Pb (36.39%) > Cr (29.22%) > As (18.82%). Among metals, Cd poses a serious threat to human health and the environment due to the calculated high percentage of mobility. Additionally, multivariate statistical techniques (principal components and cluster analyses) were applied to the chemical results to evaluate the degree of metallic pollution and the levels of association between the variables (metal-metalloids) at the different steps of sequential extraction and to recognise possible sources of potential contamination. The PCA suggests that the study area is influenced by four sources of anthropogenic contributions: acid mine drainage, industrial activities, traffic, and agriculture, aside from the natural sources characteristic of the zone. Calculated environmental risk index reveal a considerable-high ecological risk in the saltmarshes of the Huelva estuary probably related to acid mine drainage and the industrial complexes located in these areas, while in the north sector of Huelva the metallic content is more closer to the natural sources values. The results obtained suggest the need for corrective remediation measures due to the higher accumulation of potentially dangerous metals, which in most cases exceed the limits established by certain legislation.

[1]  G. Pérez,et al.  Assessment of heavy metals remobilization by fractionation: comparison of leaching tests applied to roadside sediments. , 2008, Environmental science & technology.

[2]  J. Nieto,et al.  Use of sequential extraction procedure for assessing the environmental impact at regional scale of the São Domingos Mine (Iberian Pyrite Belt) , 2008 .

[3]  Inmaculada Riba,et al.  Acid mine drainage pollution in the Tinto and Odiel rivers (Iberian Pyrite Belt, SW Spain) and bioavailability of the transported metals to the Huelva Estuary. , 2007, Environment international.

[4]  L. Dotta,et al.  Heavy Metal Speciation in the Sediments of Northern Adriatic Sea: A new Approach for Environmental Toxicity Determination , 1985 .

[5]  F. Madrid,et al.  Metals in urban soils of Sevilla: seasonal changes and relations with other soil components and plant contents , 2004 .

[6]  J. Einax,et al.  Chemometric characterization of soil and plant pollution: Part 1: Multivariate data analysis and geostatistical determination of relationship and spatial structure of inorganic contaminants in soil , 2000, Environmental science and pollution research international.

[7]  Carlos Ruiz Cánovas,et al.  Hydrochemical characteristics and seasonal influence on the pollution by acid mine drainage in the Odiel river Basin (SW Spain) , 2009 .

[8]  G. Rauret,et al.  Overview of the use of leaching/extraction tests for risk assessment of trace metals in contaminated soils and sediments , 2003 .

[9]  J. Nieto,et al.  Potential environmental impact at São Domingos mining district (Iberian Pyrite Belt, SW Iberian Peninsula): evidence from a chemical and mineralogical characterization , 2008 .

[10]  P. Janoš,et al.  Effects of inorganic and organic amendments on the mobility (leachability) of heavy metals in contaminated soil: A sequential extraction study , 2010 .

[11]  M. Žembéryová,et al.  The utilization of modified BCR three-step sequential extraction procedure for the fractionation of Cd, Cr, Cu, Ni, Pb and Zn in soil reference materials of different origins. , 2006, Talanta.

[12]  K. Yu,et al.  Assessment of heavy metal pollution in surface soils of urban parks in Beijing, China. , 2005, Chemosphere.

[13]  P. O'Connor,et al.  FOREGS GEOCHEMICAL MAPPING FIELD MANUAL , 1998 .

[14]  I. Lavilla,et al.  Evaluation of distribution, mobility and binding behaviour of heavy metals in surficial sediments of Louro River (Galicia, Spain) using chemometric analysis: a case study. , 2004, The Science of the total environment.

[15]  L. Håkanson.  An ecological risk index for aquatic pollution control.a sedimentological approach , 1980 .

[16]  F. Madrid,et al.  Estimating the extractability of potentially toxic metals in urban soils: a comparison of several extracting solutions. , 2007, Environmental pollution.

[17]  E. Achterberg,et al.  Trace metal and nutrient distribution in an extremely low pH (2.5) river–estuarine system, the Ria of Huelva (South–West Spain) , 1999 .

[18]  H. Kaiser.  The varimax criterion for analytic rotation in factor analysis , 1958 .

[19]  Rui-lian Yu,et al.  Speciation and ecological risk of heavy metals in intertidal sediments of Quanzhou Bay, China , 2010, Environmental monitoring and assessment.

[20]  J. Nieto,et al.  Speciation and ecological risk of toxic elements in estuarine sediments affected by multiple anthropogenic contributions (Guadiana saltmarshes, SW Iberian Peninsula): I. Surficial sediments. , 2011, The Science of the total environment.

[21]  Angels Sahuquillo,et al.  Use of a certified reference material for extractable trace metals to assess sources of uncertainty in the BCR three-stage sequential extraction procedure , 1999 .

[22]  M. Olías,et al.  Evaluation of the dissolved contaminant load transported by the Tinto and Odiel rivers (South West Spain) , 2006 .

[23]  J. C. Fernández-Caliani.  Risk-based assessment of multimetallic soil pollution in the industrialized peri-urban area of Huelva, Spain , 2012, Environmental Geochemistry and Health.

[24]  E. Galán,et al.  Clay mineral and heavy metal distributions in the lower estuary of Huelva and adjacent Atlantic shelf, SW Spain , 1997 .

[25]  J. Einax,et al.  The Application of Multivariate Statistical Methods for the Evaluation of Soil Profiles (8 pp) , 2007 .

[26]  Jaco Vangronsveld,et al.  Environmental exposure to cadmium and risk of cancer: a prospective population-based study. , 2006, The Lancet. Oncology.

[27]  P. C. Nagajyoti,et al.  Heavy metals, occurrence and toxicity for plants: a review , 2010 .

[28]  J. Nieto,et al.  Environmental Impact of Mining Activities in the Southern Sector of the Guadiana Basin (SW of the Iberian Peninsula) , 2009 .

[29]  J. C. Fernández-Caliani,et al.  Multi-source water pollution in a highly anthropized wetland system associated with the estuary of Huelva (SW Spain). , 2010, Marine pollution bulletin.

[30]  P. Quevauviller,et al.  Impact of industrial and mine drainage wastes on the heavy metal distribution in the drainage basin and estuary of the Sado River (Portugal). , 1989, Environmental pollution.

[31]  Anju D K Banerjee.  Heavy metal levels and solid phase speciation in street dusts of Delhi, India. , 2003, Environmental pollution.

[32]  B. B. Nayak,et al.  Geochemical speciation and risk assessment of heavy metals in the river estuarine sediments--a case study: Mahanadi basin, India. , 2011, Journal of hazardous materials.

[33]  R. Shankar,et al.  Geochemistry of two sediment cores from the west coast of India , 2005 .

[34]  J. Borrego,et al.  Geochemical variations in estuarine sediments : Provenance and environmental changes (Southern Spain) , 2006 .

[35]  F. Sanchez,et al.  El neógeno marino de la provincia de Huelva : antecedentes y definición de las unidades litoestratigráficas , 1987 .

[36]  P Quevauviller,et al.  Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials. , 1999, Journal of environmental monitoring : JEM.

[37]  A. Monaco,et al.  Reproducibility testing of a sequential extraction scheme for the determination of trace metal speciation in a marine reference sediment by inductively coupled plasma-mass spectrometry , 1997 .

[38]  Yinghua Lu,et al.  Metal and metalloid contaminant availability in Yundang Lagoon sediments, Xiamen Bay, China, after 20 years continuous rehabilitation. , 2010, Journal of hazardous materials.

[39]  J. Rincón,et al.  Heavy metal distribution and chemical speciation in tailings and soils around a Pb-Zn mine in Spain. , 2009, Journal of environmental management.

[40]  A. M. Idris.  Combining multivariate analysis and geochemical approaches for assessing heavy metal level in sediments from Sudanese harbors along the Red Sea coast , 2008 .

[41]  J. Borrego,et al.  Geochemical characteristics of heavy metal pollution in surface sediments of the Tinto and Odiel river estuary (southwestern Spain) , 2002 .

[42]  I. Jolliffe.  Principal Component Analysis , 2002 .

[43]  C. Keller,et al.  Metal availability and soil toxicity after repeated croppings of Thlaspi caerulescens in metal contaminated soils. , 2004, Environmental pollution.

[44]  S. Caeiro,et al.  Assessing heavy metal contamination in Sado Estuary sediment: An index analysis approach , 2005 .

[45]  Ş. Kartal,et al.  An Assessment on Metal Sources by Multivariate Analysis and Speciation of Metals in Soil Samples Using the BCR Sequential Extraction Procedure , 2010 .

[46]  X. Querol,et al.  Source apportionment analysis of atmospheric particulates in an industrialised urban site in southwestern Spain , 2002 .

[47]  Ş. Kartal,et al.  Multivariate analysis of the data and speciation of heavy metals in street dust samples from the Organized Industrial District in Kayseri (Turkey) , 2006 .

[48]  Andrew Hursthouse,et al.  Metal content of surface soils in parks and allotments from three European cities: initial pilot study results , 2004 .

[49]  A. Lima,et al.  Environmental geochemical mapping of Huelva municipality soils (SW Spain) as a tool to determine bac , 2011 .

[50]  F. Madrid,et al.  Distribution of heavy metal contents of urban soils in parks of Seville. , 2002, Chemosphere.

[51]  J. Nieto,et al.  Analysis of the spatial variation of heavy metals in the Guadiana Estuary sediments (SW Iberian Peninsula) based on GIS-mapping techniques. , 2010 .

[52]  J. Obbard.  Metal speciation in coastal marine sediments from Singapore using a modified BCR-sequential extraction procedure , 2006 .