Table 1.

Toxicity experiments conducted in different model organisms to understand the toxicity of microplastics

Model organism	Exposure scenario	Toxic effects	References
Zebra fish (Danio rerio)	Exposure concentration- 4 × 104 and 4 × 106 microplastics/m3 Exposure time—five days Volume of glass jar—2.2L	Cytotoxic effects-induced apoptosis and necrosis Neurotoxic effects-High Acetyl choline Esterase activity Induced oxidative stress	Guimarães et al. (2021)
Zebra fish (Danio rerio)	Exposure concentration- 10µgL—−1 and 100µgL−1 of Polystyrene microplastic beads Exposure time-35 days Sampling frequency-7 days Volume of glass aquaria- 35L	Induces reactive oxygen species (ROS) Inhibited neurotransmission Apoptosis due to upregulated expression of p53, gadd45ba and casp3b proteins Inflammatory responses due to upregulated genes of tnfa and ptgs2a	Umamaheswari et al. (2020)
Zebra fish (Danio rerio)	Exposure concentration-20 mgL−1 of pristine microplastic beads, fragments, and fibres each Exposure time-24 h	Accumulation in gut increased vacuolization and defects in cilia Induced oxidative stress Inflammation of intestines and increased permeability Gut dysbiosis	Qiao et al. (2019)
Zebra fish (Danio rerio) and Marine medaka (Oryzias melastigma)	Exposure concentration- 1% wet weight of Polyethylene microplastics and Polyvinyl chloride microplastics and spiked with different concentrations of chemicals such as Per Fluoro Alkyl Substances (PFAS), BaP, BP3 Exposure time-4 months	Decreased growth Delay in reproductive output Polyvinyl Chloride microplastics were more reprotoxic than Polyethylene microplastics Polyvinylchloride microplastics led to behavioural disruption in larvae of offspring in medaka	Cormier et al. (2021)
Zebra mussel (Dreissena polymorpha), Duck mussel (Anodonta anatine), Chinese pond musseil (Sinanodonta woodiana)	Exposure concentration- 3 particle mL−1 of 5 µm, 10 µm, 45 µm and 0.1 particle mL−1 of 90 µm sized polystyrene fragments Exposure time-48 h Volume of glass tank—10 L	Affects clearance rate of microplastics and presence of internalized microplastics are observed Smallest individuals had highest numbers of microplastics within their body Microplastics escape the filter-feed selection mechanism of mussels and enter their body	Weber et al. (2021)
Marine medaka (Oryzias melastigma)	Exposure concentration-10 mgL−1 concentration of 2, 10, 200 µm sized Polystyrene microplastic particles Exposure time-60 days	Smaller sized microplastics led to hepatic inflammation and little fibrosis Larger sized microplastics triggered metabolic disorders and induced gut dysbiosis	Zhang et al. (2021)
Mediterranean mussel (Mytilus galloprovincialis)	Exposure concentration-3 µm red polystyrene (concentration-50 particles mL−1) Exposure time-72 h	Accumulation within digestive glands Induced metabolic responses Disturbance in physiological functions	Cappello et al. (2021)
Fresh water crustacean (Daphnia magna) and Terrestrial crustacean (Porcellio scaber)	Exposure concentration—1 to 100 mg Low Density Poly ethylene (LDPE) /L of 39.8 ± 8.82 µm of virgin fragments and 205 ± 144 µm of recycled fragments for Daphnia magna and 0.5 to 15 g Low Density Polyethylene /kg soil of 39.8 ± 8.82 µm of virgin fragments and 205 ± 144 µm of recycled fragments for Porcellio scaber	Induced immune response Increased feeding rates	Kokalj et al. (2021)