Biomarkers in Soil Organisms

Pollution of agricultural soils is a topic of intense research. However, traditional approaches for assessing soil pollution such as those merely based on chemical analyses and the establishment of threshold values are insufficient to evaluate impact on soil organisms. In this context, the use of biological responses to contaminant exposure, i.e., biomarkers, can help to identify pollutant bioavailability and their potential adverse effects. Soil invertebrates are in direct contact with both soil and pore-water, so they are excellent bioindicators of soil pollution when used in combination with biomarker responses to contaminant bioavailability. The aim of this chapter is to provide an overview on the use of biomarkers for soil monitoring and assessment of remediation programs, with particular emphasis in the agroecosystem. The chapter is subdivided into five sections. The first two sections make a distinction between the concepts bioindicator, indicator or sentinel species, and biomarker. The third and fourth sections will provide an overview on what kind of information can be obtained from biomarkers and the most common biomarkers in soil ecotoxicology. The last section will summarize the main concluding remarks on this chapter and provide some lines of future research in the field of ecotoxicological biomarkers.