Geostatistical assessment of anthropogenic soil contamination using magnetometric measurements

The potential soil contamination with heavy metals can be assessed using geochemical analysis. Apart from these expensive and time consuming-methods some rapid, simple and cheap geophysical methods can be used. One of these methods is field magnetometry. Magnetic susceptibility is a convenient measure of determining the concentration of ferrimagnetic particles that serve as carriers of various pollutants such as heavy metals by rapid and non-destructive means. However, because of complex correlations between magnetic susceptibility and soil pollution the field magnetometry can not be considered as the universal method of soil pollution investigation. For each new area of investigation, the results should be reinterpreted taking into account not only the type of pollution but also many pedogenic, biogenic and environmental factors. In practice, it is very difficult to measure and consider all these factors. This is why further improvement of the magnetometric method is necessary to allow the technique to be used as quantitative tool for soil pollution investigations. In particular, the interpretation of results should be improved. Geostatistical methods, which are focused on the spatial variability of a studied phenomenon, are an effective tool for field magnetometry applications and interpretation of its results. This paper describes the role of the geostatistical methods in the standardization of field magnetometry. Different measurement and geostatistical modeling strategies are presented, compared and discussed. The paper includes also a case study in which the geostatistical contribution to standardization of the magnetometric method is thoroughly demonstrated. Moreover, the paper discusses practical aspects of geostatistical standardization of magnetometric methods to allow for easy use them during surveys.