Microplastic-Earthworm Interactions: A Critical Review

Microplastics generated from diverse categories of plastic wastes primarily accumulate in terrestrial ecosystems and subsequently find their way to aquatic ecosystems. As the use of plastic goods has been increasing globally during the last few decades, it is likely that the amount of microplastics too would increase significantly and get accumulated in the soil. An increased level of microplastics might have deleterious effects on soil properties and microbiota. Microplastics being small (< 5 mm), could be easily consumed by pedophagous soil fauna such as earthworms and get dispersed widely in soil and might even reach the groundwater table. It has been reported that microplastics such as polyvinyl chloride, polypropylene etc., can bind to toxic compounds, including pesticides and transfer these into the gut of earthworms, adversely impacting their growth, ecological functions, and reproduction. It is apprehended that earthworms and other soil fauna could accelerate the degradation of microplastics into nano forms which could enhance environmental risk not only for these animals but also for other beneficial soil biotas.