Extrapolation of imidacloprid toxicity between soils by exposing Folsomia candida in soil pore water

Abstract

Soil properties like organic matter (OM) content show great variation, making it hard to predict the fate and effects of a chemical in different soils. We therefore addressed the question: can we remove the complexity of the soil matrix and yet accurately predict soil toxicity from porewater exposures? Folsomia candida was exposed to imidacloprid in natural (LUFA 2.2 [4.02% OM], Grassland [12.6% OM]) and artificial soils (OECD 5 [6.61% OM], OECD 10 [10.8% OM]), in pore water extracted from spiked LUFA 2.2 soil and in water. Toxicity decreased with increasing OM content except for Grassland soil, which had the highest OM content but the lowest clay content, suggesting a role of clay minerals in the binding of imidacloprid. Distribution coefficients for imidacloprid based on toxicity (Toxicity-Kd) were derived by comparing effect concentrations in LUFA 2.2 soil and in water. Using these Toxicity-Kds to recalculate soil LC50s/EC50s to porewater concentrations, the differences in LC50/EC50s almost disappeared. The recalculated porewater LC50s did not differ by more than a factor of 0.55–1.43 from the LC50 obtained upon water exposure. This similarity suggests that the toxicity in the soil is dependent on porewater concentrations and can be obtained from water exposure. The porewater test and the corresponding “pore-water extrapolation concept” developed in this study may be used to predict the toxicity of chemicals in the soil and extrapolate among different soils.

A Multiple Life‐History Trait–Based and Time‐Resolved Assessment of Imidacloprid Effects and Recovery in the Widely Distributed Collembolan Folsomia quadrioculata

“…This was, for instance, also shown for copper uptake effects on springtails by Bruus Pedersen et al (2000). Soil porewater absorption through the cuticle and ventral tube is a major route of imidacloprid exposure, and Ogungbemi and van Gestel (2018) have shown that exposure through porewater can closely resemble the exposure scenarios in soil.…”

“…Several mechanisms can drive this phenomenon. Firstly, the collembolans suffer from disoriented movements and spasms owing to the neurotoxic effects of imidacloprid (Ogungbemi and van Gestel 2018). This might lead to uncontrolled loss of energy, which reduces the resources available for reproduction (Anderson and Harmon-Threatt 2019) or altered sexual behavior (Haynes 1988).…”

“…Collembolans are exposed to imidacloprid by direct diffusion of water through the cuticle (particularly in the ventral tube) and potentially through the diet by feeding on contaminated soil organic matter. The imidacloprid concentration in soil porewater can serve as a proxy of the severity of exposure for collembolans in soil (Ogungbemi and van Gestel 2018). The collembolan Folsomia candida , which is widely used in standard toxicity tests (Organisation for Economic Co‐operation and Development 2009), is highly sensitive to imidacloprid in terms of reproduction and survival when exposed through soil or porewater (Idinger 2002; Ogungbemi and van Gestel 2018; de Lima e Silva et al 2020), implying that long‐term chronic exposure can have strong adverse effects on natural collembolan populations.…”

Molecular Dynamics Insights for Screening the Ability of Polymers to Remove Pesticides from Water

“…These pesticides are widely used for different crops, as the tomato one, which is quite common in Mediterranean countries. Despite the relevance of these pesticides for the economy, their impact on the biotic cannot be neglected ,. The screening strategy proposed in the present study resorts to MD simulations, which allows for a detailed investigation about the main interactions that promote the formation of the oligomer‐pesticide complex.…”

Toxicity of imidacloprid to collembolans in two tropical soils under different soil moisture

“…(2014) and the PBMC (2014), for 90% of Brazilian biomes, reductions in precipitation regimes by 5–20% are expected by 2040, 20–35% between the years 2041 to 2070, and 30–50% from 2071 to 2100. Reductions in soil moisture are also expected (Dai, 2013) that can negatively affect the habitat of edaphic organisms, which play crucial roles in cycling nutrients, decomposition of organic matter, maintenance of soil structure, permeability, and gas exchange (Edwards, Arancon, Vasko‐Bennett, Little, & Askar, 2008; Ogungbemi & Van Gestel, 2018; Phelan et al., 2016).…”