Food chain-mediated variation in excretion times of microplastics: Unraveling the interactions with plasticizers

Abstract

Microplastics are global environmental pollutants. Further, there has been growing concern regarding the contamination of plasticizers. In this study, we first found that Daphnia magna mistakenly ingests microplastics of red, blue, yellow, green, black, white, and clear colors. Next, using Daphnia magna (crustacean) and zebrafish (fish), we investigated whether the time required to expel microplastics varies when ingestion occurs through a food-chain and found that microplastics excretion occurs within 48 h and 24 h for direct ingestion and ingestion through food chain (via Daphnia magna), respectively. Lastly, we examined whether acute toxicity values varied when Daphnia magna was exposed to a combination of plasticizers and microplastics, compared to exposure to plasticizers alone, and found that that there were no differences in the acute toxicity values. This study provides important data for investigating the impacts of microplastics on ecosystems and is expected to contribute to future ecological risk assessments of microplastics.