non-destructive tissues (e.g. coelomocytes) that do not require sacrifice, the incorporation of “omic” disciplines and recent technical advances in metabolite identification are all encouraged to be incorporated into toxicity evaluation.
Keywords Biochemical biomarkers, Endogeic earthworms, Soil toxicity
assessment
1 Introduction
This chapter focusses on the use of earthworms from different ecological categories,
epigeic, endogeic and anecic (see Chap. 11), as sentinels in toxicity monitoring in
relation to soil assessment [1]. It will address the works published after some
comprehensive reviews [2] on the use of biomarkers in earthworms or particular
review issues addressing pesticide pollution [3, 4]. The use of earthworms as
sentinels and sublethal biomarkers in soil pollution assessment is well recognised
in terrestrial ecotoxicology, mostly in relation to metal and pesticide pollution [5–
8]. This chapter will focus on more recent work (from 2015 onwards) dealing with
the use of biomarkers for assessing the toxicity associated with legacy chemicals
(e.g. heavy metals, pesticides) and will also include emerging contaminants or
contaminants of increasing environmental concern such as nanomaterials, pharmaceutical drugs, plastics, plastic additives and e-waste-related products as well as
environmentally realistic mixtures of chemicals. Another chapter in this book by
Sanchez-Hernandez (Chap. 11) addresses the role of earthworms as
vermiremediators of chemical pollution in soils, and thus, this aspect will not be
considered here. Only if the vermiremediation study includes earthworm biomarkers
will it be mentioned in this chapter. In Fig. 1, a scheme of the topics described
throughout the text is presented.
The first ecotoxicology tests adopted by the international Organisation for Economic Co-operation and Development (OECD) directives [9] were based on mortality and aimed at obtaining LC50 values for toxic chemicals. Subsequently, effects
on sublethal responses, such as reproductive performance, were included [10]. More
recently, the incorporation of enzymatic, molecular (genetic and metabolomics) and
even behaviour biomarkers in the ecotoxicity tests has gained relevance as indicators
of sublethal toxicity. The importance of using infra-individual responses
(e.g. enzymatic activities and molecular alterations) rests mostly on being quick
signs of potential toxic events and on the possibility of extrapolating to further
individually and ecologically relevant consequences [11]. In relation to the selection
of adequate bioindicator species, the epigeic Eisenia fetida and Eisenia andrei are
those adopted in soil toxicity tests following OECD protocols, and therefore a larger
body of research is conducted with them. However, this chapter will purposely give
support to the studies conducted with the naturally occurring species in agricultural
312
M. Solé
Keywords Biochemical biomarkers, Endogeic earthworms, Soil toxicity
assessment
1 Introduction
This chapter focusses on the use of earthworms from different ecological categories,
epigeic, endogeic and anecic (see Chap. 11), as sentinels in toxicity monitoring in
relation to soil assessment [1]. It will address the works published after some
comprehensive reviews [2] on the use of biomarkers in earthworms or particular
review issues addressing pesticide pollution [3, 4]. The use of earthworms as
sentinels and sublethal biomarkers in soil pollution assessment is well recognised
in terrestrial ecotoxicology, mostly in relation to metal and pesticide pollution [5–
8]. This chapter will focus on more recent work (from 2015 onwards) dealing with
the use of biomarkers for assessing the toxicity associated with legacy chemicals
(e.g. heavy metals, pesticides) and will also include emerging contaminants or
contaminants of increasing environmental concern such as nanomaterials, pharmaceutical drugs, plastics, plastic additives and e-waste-related products as well as
environmentally realistic mixtures of chemicals. Another chapter in this book by
Sanchez-Hernandez (Chap. 11) addresses the role of earthworms as
vermiremediators of chemical pollution in soils, and thus, this aspect will not be
considered here. Only if the vermiremediation study includes earthworm biomarkers
will it be mentioned in this chapter. In Fig. 1, a scheme of the topics described
throughout the text is presented.
The first ecotoxicology tests adopted by the international Organisation for Economic Co-operation and Development (OECD) directives [9] were based on mortality and aimed at obtaining LC50 values for toxic chemicals. Subsequently, effects
on sublethal responses, such as reproductive performance, were included [10]. More
recently, the incorporation of enzymatic, molecular (genetic and metabolomics) and
even behaviour biomarkers in the ecotoxicity tests has gained relevance as indicators
of sublethal toxicity. The importance of using infra-individual responses
(e.g. enzymatic activities and molecular alterations) rests mostly on being quick
signs of potential toxic events and on the possibility of extrapolating to further
individually and ecologically relevant consequences [11]. In relation to the selection
of adequate bioindicator species, the epigeic Eisenia fetida and Eisenia andrei are
those adopted in soil toxicity tests following OECD protocols, and therefore a larger
body of research is conducted with them. However, this chapter will purposely give
support to the studies conducted with the naturally occurring species in agricultural
312
M. Solé