Abstract
A total of 286 soil samples were collected in the Cova dos Mouros area. All samples were dry sieved into the <200 mesh size fraction and analysed for Fe, Cu, Zn, Pb, Co, Ni, Bi and Mn by atomic absorption spectrometry (AAS) and for As, Se, Sb and Te by atomic absorption spectrometry-hydrid generation (AAS-HG). Only the results of arsenic are discussed in this paper although the survey was extended to all analysed chemical elements. The purpose of this study was to make a risk probability mapping for arsenic that would allow better knowledge about the vulnerability of the soil to arsenic contamination. To achieve this purpose, the initial variable was transformed into an indicator variable using as thresholds the risk-based standards (intervention values) for soils, as proposed by [Swartjes 1999. Risk based assessment of soil and groundwater quality in the Netherlands: Standards and remediation. J. Geochem. Explor.73 1–10]. To account for spatial structure, sample variograms were computed for the main directions of the sampling grid and a spherical model was fitted to each sample variogram (arsenic variable and indicator variables). The parameters of the spherical model fitted to the arsenic variable were used to predict arsenic concentrations at unsampled locations. A risk probability mapping was also done to assess the vulnerability of the soil towards the mining works. The parameters of the spherical model fitted to each indicator variable were used to estimate probabilities of exceeding the corresponding threshold. The use of indicator kriging as an alternative to ordinary kriging for the soil data of Cova dos Mouros produced unbiased probability maps that allowed assessment of the quality of the soil.
Similar content being viewed by others
References
GEM. Aslin (1976) ArticleTitleThe determination of arsenic and antimony in geological materials by flame atomic absorption spectrometry J Geochem Explor 6 321–330 Occurrence Handle10.1016/0375-6742(76)90021-2
J Carvalho Cardoso M Teixeira Bessa M. Branco Marado (1971) ArticleTitleCarta dos solos de Portugal (1:1000000) Agronomia Lusitana 33 IssueID1/4 481–602
RG. Garrett (1969) ArticleTitleThe determination of sampling and analytical errors in exploration geochemistry. Eco Geol 64 568–574
RG. Garrett (1973) ArticleTitleThe determination of sampling and analytical errors in exploration geochemistry – a reply Econ Geol 68 282–283
P. Goovaerts (1997) Geostatistics for Natural Resources Evaluation University Press Oxford, New-York
P. Goovaerts (1999) ArticleTitleGeostatistics in soil science: state-of-the-art and perspectives Geoderma 89 1–45 Occurrence Handle10.1016/S0016-7061(98)00078-0
InstitutionalAuthorNameIGM (1990) Gold Exploration at Marrancos-Portela das Cabras. Vila Verde – Braga IGM Portugal (in Portuguese)
EH Isaaks RM. Srivastava (1989) An Introduction to Applied Geostatistics Oxford University Press Oxford 561
Medeiros AC, Teixeira C, Teixeira Lopes J. 1974 Carta geológica, escala 1/50000, n° 5-B e respectiva Notícia Explicativa. Serviços Geológicos de Portugal (in Portuguese).
F Noronha JMF. Ramos (1993) ArticleTitleMineralizações auríferas no Norte de Portugal. Algumas reflexões Cuaderno, Lab. Xeolóxico de Laxe, Coruña 18 133–146
AP Reis AJ Sousa E. Cardoso Fonseca (2001) ArticleTitleSoil geochemical prospecting for gold at Marrancos (Northern Portugal) J Geochem Explor 73 1–10 Occurrence Handle10.1016/S0375-6742(01)00169-8
AF. Swartjes (1999) ArticleTitleRisk-based assessment of soil and groundwater quality in the Netherlands: Standards and remediation urgency Risk Analysis 19 IssueID6 1235–1249 Occurrence Handle10.1023/A:1007003332488 Occurrence Handle10765460
Techtron Varian (1984) VGA-76 Vapor Generation Accessory Varian Techtron, Victoria Australia 27
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Reis, A.P., Sousa, A.J., Silva, E.F.D. et al. Application of geostatistical methods to arsenic data from soil samples of the Cova dos Mouros mine (Vila Verde-Portugal). Environ Geochem Health 27, 259–270 (2005). https://doi.org/10.1007/s10653-004-5554-y
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10653-004-5554-y