title: Towards an integrative soil health assessment strategy: a three tier (integrative biomarker response) approach with Eisenia fetida applied to soils subjected to chronic metal pollution.
abstract: This is a pilot study for assessing soil ecosystem health in chronically polluted sites on the basis of a 3-tier approach (screening+scoring+understanding) designed to be cost-effective and scientifically based, and to provide straightforward advice and support to managers and stakeholders involved in environmental protection. For the initial screening (Tier 1), the use of a highly sensitive, low-cost biomarker such as neutral red uptake (NRU) in earthworm coelomocytes is proposed. In sites where an alteration in NRU has been established, the stress level may be further assessed by utilising a suite of low-cost and rapid biomarkers of effect integrated in an integrative biological response (IBR) index to obtain an objective (scored) assessment of the induced stress syndrome (Tier 2). The IBR/n index is based on the integration of biomarkers at different levels of biological organisation. Acyl-CoA oxidase activity (AOX), catalase activity (CAT), lipofuscin optical density (LOD%), NRU and the mean epithelial thickness (MET) have been used to calculate the IBR/n index. Biomarkers are determined in earthworms, Eisenia fetida, exposed ex situ to real soils (three mining sites and a reference) for 3, 10 and 17d. The 3d NRU (Tier 1) provided signal of stress. After 3d, PCA, based on the suite of biomarkers (Tier 2), discriminated reference and polluted sites according to toxicity profiles and at 17d, the most polluted site is segregated from less polluted and reference sites. Soils were classified as harmful, unhealthy (not apparently toxic) or healthy. Soils were investigated by microarray transcriptomics (Tier 3), to understand the causes (aetiology) and consequences (prognosis) of health impairment. Tier 3 discriminates, according to stress syndrome traits, soils that did not fall into the category of highly stressed and revealed the main agent causing toxicity at each site by identifying the toxicity mechanisms and biological responses.
authors.affiliation: EKOIZ-BERRILUR Research Consortium. Cell Biology & Environmental Toxicology Research Group, Zoology & Animal Cell Biology Department, Faculty of Science & Technology, University of the Basque Country, P.O. Box 644, E-48080 Bilbo, Basque Country, Spain.
authors.forename: Vega
authors.initials: V
authors.lastname: Asensio
authors.forename: Amaia
authors.initials: A
authors.lastname: Rodríguez-Ruiz
authors.forename: Larraitz
authors.initials: L
authors.lastname: Garmendia
authors.forename: Jane
authors.initials: J
authors.lastname: Andre
authors.forename: Peter
authors.initials: P
authors.lastname: Kille
authors.forename: Andrew John
authors.initials: AJ
authors.lastname: Morgan
authors.forename: Manu
authors.initials: M
authors.lastname: Soto
authors.forename: Ionan
authors.initials: I
authors.lastname: Marigómez
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis / Q000633:toxicity; D008906:Mining; D009835:Oligochaeta / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D010865:Pilot Projects; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity; D013030:Spain; D059467:Transcriptome
chemical_list: D015415:Biomarkers; D019216:Metals, Heavy; D012989:Soil Pollutants