How Can Nanoplastics Affect the Survival, Reproduction, and Behaviour of the Soil Model Enchytraeus crypticus?

Abstract

Nanoplastics (NPls) are ubiquitous in terrestrial environments, with numerous consequences for biodiversity and ecosystems. Research is urgently required to clarify the NPls environmental behaviour, fate and ecotoxicological effects to soil ecosystems. The aim of this research was to assess and comprehend the effects of polystyrene NPls to the terrestrial species Enchytraeus crypticus using survival, reproduction and avoidance behaviour as endpoints. A range of concentrations, 0.015 to 1500 mg NPls/kg LUFA 2.2 (Landwirtschaftliche Untersuchungs- und Forschungsanstalt Speyer, Germany) soil, was tested. Due to the effect of tween 20 and sodium azide (NaN3) on the NPls dispersion, the effects of these compounds were also assessed separately. After 21 d, 1200 and 1500 mg/kg NPls dispersion had significant effects on the organism survival and/or reproduction. However, these effects may be mainly associated with tween 20 and NaN3 present in the NPls dispersion and not with NPls themselves. After 48 h, there was a tendency of the organisms to avoid the NPls spiked soils, being this response significant at 0.015 mg/kg although a reduced avoidance behaviour was observed as NPls concentration increased. The present study provides screening data on the effects of NPls, alone and considering the presence of other compounds like the solvents, which is essential for regulators and strategic management of plastic pollution.

Co-Exposure of Nanopolystyrene and Other Environmental Contaminants—Their Toxic Effects on the Survival and Reproduction of Enchytraeus crypticus

“…Despite the few studies available involving E. crypticus and polystyrene-based NPls [11,30], one study showed that NPls (mean diameter: 60 nm) induced no effects in organisms' survival or reproduction at concentrations from 0.015 to 900 mg/kg [11]. The previous study is in accordance with the findings of the current study (absence of effects of NPls).…”

“…Soil spiking was performed according to the following experimental conditions: single exposures of NPls (1.5 and 300 mg/kg) and DPH, AgNO 3 and VNPs (10 and 50 mg/kg), as well as the binary mixtures of NPls with each co-contaminant (1.5 mg NPls/kg + 10 mg DPH/kg; 1.5 mg NPls/kg + 50 mg DPH/kg; 300 mg NPls/kg + 10 mg DPH/kg; 300 mg NPls/kg + 50 mg DPH/kg; 1.5 mg NPls/kg + 10 mg AgNO 3 /kg; 1.5 mg NPls/kg + 50 mg AgNO 3 /kg; 300 mg NPls/kg + 10 mg AgNO 3 /kg; 300 mg NPls/kg + 50 mg AgNO 3 /kg; 1.5 mg NPls/kg + 10 mg VNPs/kg; 1.5 mg NPls/kg + 50 mg VNPs/kg; 300 mg NPls/kg + 10 mg VNPs/kg; 300 mg NPls/kg + 50 mg VNPs/kg). The selected single VNPs, AgNO 3 and NPls concentrations, the toxicities of which were previously studied [10,11,25], were used to examine the role of NPls in the toxicity of those contaminants. For DPH concentrations, its effects on E. crypticus were not known yet (single and combined with NPls).…”

“…Through diverse processes, e.g., aggregation and agglomeration, these contaminants can form complexes with NPls, altering their bioavailability to soil organisms, such as invertebrates and plants [9]. Therefore, there is the concern that the accumulation of NPls and interaction with other contaminants can potentiate the already reported toxic effects for each single compound through antagonistic or synergistic interactions [10][11][12][13].…”

“…Being a soft-bodied invertebrate, uptake is made via ingestion (e.g., food and soil particles) or via the body surface or dermis (used for gaseous exchange and water uptake) [24]. Previous studies already successfully used E. crypticus to test the effects of different anthropogenic contaminants (e.g., metals, NPls and NMs) [10,11,25].…”

New Insights into Nanoplastics Ecotoxicology: Effects of Long-Term Polystyrene Nanoparticles Exposure on Folsomia candida

“…Assessing multigenerational effects allows us to understand the full impact of contaminants on populations over time as many contaminants can have long-lasting effects that are not immediately apparent [9]. Indeed, some studies have reported no significant effects on the survival and reproduction of terrestrial invertebrate species such as Folsomia candida [10] and Enchytraeus crypticus [11] after 28 and 21 days (d) NPls exposure, respectively. Therefore, it is essential to determine whether the absence of effects observed in a standard reproduction test persists through subsequent generations.…”