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.