Earthworms exposed to microplastics (PE and biodegradable)

While much is known about microplastics in aquatic environments, only few studies have focused on how microplastics interact with terrestrial organisms. The objective of our study was to investigate the interactions of earthworms with microplastics in a natural environment with environmentally realistic plastic concentrations. We investigated whether earthworms would ingest microplastics and incorporate them into their bodies and cast, and whether microplastics wouldalter the intestinal and soil microbiome. Lumbricus terrestris was exposed to two types of microplastics, biodegradable polybutylene adipate terephthalate (PBAT) and low-density polyethylene (LDPE) in mesocosoms filled with natural soil. Earthworms did not show macroscopic health deterioration (weight loss, vitality) and microbial analysis showed that microplastic treatments did not result in a statistically significant change in bacterial richness, diversity or community composition for soil, casts or guts compared to controls. Taken together, our results suggest that at environmentally realistic concentrations and short exposure times, PBAT and LDPE microplastics do not have adverse effects on Lumbricus terrestris earthworms.