Soil ecotoxicology: state of the art and future directions

Abstract

Developments in soil ecotoxicology started with observations on pesticide effects on soil invertebrates in the 1960s. To support the risk assessment of chemicals, in the 1980s and 1990s development of toxicity tests was the main issue, including single species tests and also more realistic test systems like model ecosystems and field tests focusing on structural and functional endpoints. In the mean time, awareness grew about issues like bioavailability and routes of exposure, while biochemical endpoints (biomarkers) were proposed as sensitive and potential early-warning tools. In recent years, interactions between different chemicals (mixture toxicity) and between chemical and other stressors attracted scientific interest. With the development of molecular biology, omics tools are gaining increasing interest, while the ecological relevance of exposure and effects is translating into concepts like (chemical) stress ecology, ecological vulnerability and trait-based approaches. This contribution addresses historical developments and focuses on current issues in soil ecotoxicology. It is concluded that soil ecotoxicological risk assessment would benefit from extending the available battery of toxicity tests by including e.g. isopods, by paying more attention to exposure, bioavailability and toxicokinetics, and by developing more insight into the ecology of soil organisms to support better understanding of exposure and long-term consequences of chemical exposure at the individual, population and community level. Ecotoxicogenomics tools may also be helpful in this, but will require considerable further research before they can be applied in the practice of soil ecotoxicological risk assessment.

Assessment of the bioavailability and toxicity of lead polluted soils using a combination of chemical approaches and bioassays with the collembolan Folsomia candida

“…To address the relevance of chemical extraction methods for risk assessment, the analytically extracted metal concentrations need to be interpreted in a biological context [5]. There is an increasing need to incorporate bioassays in risk assessments and hazard identification [6,7]. Bioassays with soil animals however, may also present some problems: acute tests, for instance, do not provide an insight into the effects of the contaminant on population dynamics while chronic tests are time-consuming and labor intensive [8].…”

“…When combined with environmental chemistry of naturally aged soils, bioassays (including avoidance tests) provide more complete and relevant information on contaminant bioavailability in soils and, therefore a more meaningful and holistic risk assessment of contaminated sites [9,16]. To considerably improve site-specific risk assessment of Pb-contaminated land, it is highly recommended to combine soil characterization, chemical extraction methods and bioassays [7,9,10].…”

Earthworm avoidance behavior to antimicrobial sulfadiazine on tropical artificial soil

“…Van Gestel (2012) states that the avoidance response may be an endpoint as sensitive as reproduction for some chemicals, while it may be as sensitive as survival for other substances.…”

“…The repellency of some chemicals over terrestrial fauna has been known and assessed for years on several animal taxa, as Annelida, Collembola, Isopoda, Acari, among others (Eijsackers, 1978;Hund-Rinke et al, 2003;Aldaya et al, 2006;Van Gestel, 2012), usually employing their chemical sensors and signals to avoid deleterious food or habitat.…”

Avaliação ecotoxicológica da vinhaça de cana-de-açúcar no solo

“…A seguir, um conjunto de novas metodologias foi desenvolvido e a base de dados de testes ecotoxicológicos terrestres cresceu consideravelmente (LØKKE; VAN GESTEL, 1998;GOMEZ-EYLES et al, 2009 Tropical por pesquisadores brasileiros, em conjunto com grupos internacionais (GARCIA, 2004;JÄNSCH;GARCIA;RÖMBKE, 2005;RÖMBKE et al, 2005, CHELINHO et al, 2011, 2012NIEMEYER et al, 2010NIEMEYER et al, , 2012aNUNES;ESPÍNDOLA, 2012;BUCH et al, 2013;ALVES et al, 2013ALVES et al, , 2014 1996).…”