Long Term Exposure to Virgin and Recycled LDPE Microplastics Induced Minor Effects in the Freshwater and Terrestrial Crustaceans Daphnia magna and Porcellio scaber

Abstract

The effects of microplastics (MP) are extensively studied, yet hazard data from long-term exposure studies are scarce. Moreover, for sustainable circular use in the future, knowledge on the biological impact of recycled plastics is essential. The aim of this study was to provide long-term toxicity data of virgin vs recycled (mechanical recycling) low density polyethylene (LDPE) for two commonly used ecotoxicity models, the freshwater crustacean Daphnia magna and the terrestrial crustacean Porcellio scaber. LDPE MP was tested as fragments of 39.8 ± 8.82 µm (virgin) and 205 ± 144 µm (recycled) at chronic exposure levels of 1–100 mg LDPE/L (D. magna) and 0.2–15 g LDPE/kg soil (P. scaber). Mortality, reproduction, body length, total lipid content, feeding and immune response were evaluated. With the exception of very low inconsistent offspring mortality at 10 mg/L and 100 mg/L of recycled LDPE, no MP exposure-related adverse effects were recorded for D. magna. For P. scaber, increased feeding on non-contaminated leaves was observed for virgin LDPE at 5 g/kg and 15 g/kg. In addition, both LDPE induced a slight immune response at 5 g/kg and 15 g/kg with more parameters altered for virgin LDPE. Our results indicated different sublethal responses upon exposure to recycled compared to virgin LDPE MP.

A Comparative Study of Several Properties of Plywood Bonded with Virgin and Recycled LDPE Films

“…The identification of these chemical additives is quite a difficult concern. It was established that the chemical composition of recycled LDPE was not more complex than that of virgin LDPE [ 31 ]. The authors explain this by the fact that in the process of recycling, organic compounds may be partially or selectively removed in the cleaning and/or extrusion steps of the recyclate [ 31 ].…”

“…It was established that the chemical composition of recycled LDPE was not more complex than that of virgin LDPE [ 31 ]. The authors explain this by the fact that in the process of recycling, organic compounds may be partially or selectively removed in the cleaning and/or extrusion steps of the recyclate [ 31 ]. Moreover, the recycled LDPE has higher tensile strength and shrinkage, but a lower mass flow index compared to virgin LDPE [ 32 ].…”

The effect of microplastics on Daphnia fitness – Systematic review and meta‐analysis

“…Nevertheless, within single studies testing different concentrations of the same micro/nanoplastic particle size, toxicity typically increased with particle concentration, resulting in higher mortality and decreased reproduction in Daphnia (e.g., Besseling et al, 2014;Fadare et al, 2019;Nogueira et al, 2022). Studies deviating from this trend usually did not find toxic effects on Daphnia for any of the tested micro/nanoplastic concentrations (e.g., Jemec Kokalj et al, 2021Kalčíková et al, 2020).…”

Microplastics and Their Impact on Reproduction—Can we Learn From the C. elegans Model?

“…In the amphipod, Hyalelia azteca , and in the water flea a greater decrease in reproduction was observed with lower number of broods at lower MP concentrations upon fiber exposure than with plastic beads ( Au et al, 2015 ; Ziajahromi et al, 2017 ). In the earthworm ( Lumbricus terrestris ) ( Huerta-Lwanga et al, 2021 ) and springtail ( Folsomia candida ), microfibers decreased reproduction by inhibiting spermatogenesis ( Jemec Kokalj et al, 2021 ). In the earthworm Eisenia andreii , PE-MP breakdown into NP induced sperm damage and decreased number of sperm bundles but did not cause damage to the oocyte in females, showing sexually dimorphic reproductive toxicity ( Jeong et al, 2021 ).…”