Microplastics as a vector of toxic chemicals in soil: Enhanced uptake of perfluorooctane sulfonate and perfluorooctanoic acid by earthworms through sorption and reproductive toxicity

Abstract

The accumulation of microplastics (MP) in soil via their continuous release and degradation of large plastics has recently become a serious global problem. The major concern with MP is their potential to sorb pollutants as well as ingestion by living organisms. Hence, this study focused on the effect of PVC MP exposure on increasing the risk of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) bioaccumulation in earthworms in addition to their reproduction. In general, the bioaccumulation factor (BAF) for PFOA and PFOS increased up to 200% in earthworms exposed to MP-contaminated soil. MP at 500 and 1000 mg kg −1 soil caused enhanced uptake of PFOS and PFOA in earthworms, and a significant reduction in their reproduction. These results have significant implications for risk assessment of MP in soil. • PVC microplastics enhanced PFOS/PFOA uptake by earthworms. • PVC microplastics (PVC MPs) did not cause acute toxicity in earthworms. • PVC MPs at 1000 mg/kg soil decreased reproduction in earthworms. • PVC MPs acted as vectors for PFOS/PFOA uptake by earthworms. • PVC MPs enhanced reproductive toxicity in the presence of PFOS/PFOA.