Bioaccumulation and Toxicity of Organic Chemicals in Terrestrial Invertebrates

Terrestrial invertebrates are key components in ecosystems, with crucial roles in soil structure, functioning, and ecosystem services. The present chapter covers how terrestrial invertebrates are impacted by organic chemicals, focusing on up-to-date information regarding bioavailability, exposure routes and general concepts on bioaccumulation, toxicity, and existing models. Terrestrial invertebrates are exposed to organic chemicals through different routes, which are dependent on both the organismal traits and nature of exposure, including chemical properties and media characteristics. Bioaccumulation and toxicity data for several groups of organic chemicals are presented and discussed, attempting to cover plant protection products (herbicides, insecticides, fungicides, and molluscicides), veterinary and human pharmaceuticals, polycyclic aromatic compounds, polychlorinated biphenyls, flame retardants, and personal care products. Chemical mixtures are also discussed bearing in mind that chemicals appear simultaneously in the environment. The biomagnification of organic chemicals is considered in light of the consumption of terrestrial invertebrates as novel feed and food sources. This chapter highlights how science has contributed with data from the last 5 years, providing evidence on bioavailability, bioaccumulation, and toxicity derived from exposure to organic chemicals, including insights into the main challenges and shortcomings to extrapolate results to real exposure scenarios

Biomarkers in Earthworms

27 pagesSoil-dwelling naturally occurring earthworms (e.g. Lumbricus terrestris) are valuable sentinels in soil pollution monitoring for their ecological role but also because they have shown to be sensitive to environmental contaminants. However, most laboratory studies have adopted epigeic earthworms as models (Eisenia spp.) in acute toxicity testing. In soil chronic toxicity assessment, it is essential to include sublethal responses that can have direct implications on species performance, reproduction and behaviour and thus be of ecological significance. In this sense, some biochemical biomarkers are regarded as early warning signals of further ecological consequences. Amongst those most frequently considered are specific responses to certain chemicals (e.g. metallothionein induction to metal exposure) but also those related to oxidative homeostasis of the organisms because prolonged stress may lead to adverse effects at the individual level (disruption of immune system, altered growth and reproduction). Biomarker measures can be applied in specific tissues, but, for methodological constraints, the consideration of the whole animal simplifies protocols and, once validated, they are informative and integrative. The use of 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 evaluationTo the EU Water JPI-2015 AWARE project (PCIN-2017-067), D. Nos and D. Romano are thanked for their contribution to the projectPeer reviewe