Toxicity and behavioral response of zebrafish exposed to combined microplastic and bisphenol analogues

Microplastics and bisphenol analogues are emerging environmental pollutants widely occurring in freshwaters. Harmful effects of microplastics and bisphenols have been studied individually, yet there is few knowledge on their combined effect. Here, we conducted acute toxicity tests using embryonic and larval zebrafish to assess the combined lethality after co-exposure of bisphenol A or F and 0.5- and 25-μm polystyrene microplastic particles. We monitored the accumulation of microplastics in zebrafish. We also studied the impact on the behavior of larval zebrafish. Results show that co-exposure of bisphenols and polystyrene microplastics increased lethality of larvae by 6.8–51% for bisphenol F and by 6.7–30.1% for bisphenol A. However, the bisphenol lethality toward embryos remains unchanged in the presence of microplastics. Fluorescence analysis shows that 0.5- and 25-μm microplastics accumulate in the larvae gastrointestinal area in a dose-dependent pattern, but did not concentrate in the embryo. Overall, co-exposure of polystyrene microplastics and bisphenol analogues displayed stronger behavioral effects, e.g. reduced moving distance and activity,) toward zebrafish larvae, compared with single pollutant exposure.