Screening of the Toxicity of Polystyrene Nano- and Microplastics Alone and in Combination with Benzo(a)pyrene in Brine Shrimp Larvae and Zebrafish Embryos

Abstract

The occurrence of nanoplastics (NPs) and microplastics (MPs) in aquatic ecosystems and their capacity to sorb hydrophobic pollutants is nowadays an issue of great concern. This study aimed to assess the potential bioavailability and acute toxicity of polystyrene (PS) NPs (50 and 500 nm) and of MPs (4.5 µm), alone and with sorbed benzo(a)pyrene (B(a)P), in the embryo/larval stages of brine shrimps and zebrafish. Exposure to pristine plastics up to 50.1 mg PS/L did not cause significant impact on brine shrimp survival, while some treatments of plastics-B(a)P and all concentrations of B(a)P (0.1–10 mg/L) resulted acutely toxic. In zebrafish, only the highest concentrations of MPs-B(a)P and B(a)P caused a significant increase of malformation prevalence. Ingestion of NPs was observed by 24–48 h of exposure in the two organisms (from 0.069 to 6.87 mg PS/L). In brine shrimps, NPs were observed over the body surface and within the digestive tract, associated with feces. In zebrafish, NPs were localized in the eyes, yolk sac, and tail at 72 h, showing their capacity to translocate and spread into the embryo. MP ingestion was only demonstrated for brine shrimps. In zebrafish embryos exposed to plastics-B(a)P, B(a)P appeared in the yolk sac of the embryos. The presence of B(a)P was also noticeable in brine shrimps exposed to 500 nm NPs-B(a)P. In conclusion, NPs entered and spread into the zebrafish embryo and PS NPs, and MPs were successful vectors of B(a)P to brine shrimp and zebrafish embryos. Particle size played a significant role in explaining the toxicity of plastics–B(a)P. Our study provides support for the idea that plastics may pose a risk to aquatic organisms when combined with persistent organic pollutants such as B(a)P.

Comparative toxicity of polystyrene, polypropylene, and polyethylene nanoplastics on Artemia franciscana nauplii: a multidimensional assessment

“…The rate of nauplii mortality increased with the exposure concentration, reaching >70% at 100 mg L −1 , 50–60% at 50 mg L −1 , 30–35% at 5 mg L −1 , and <20% at 0.5 mg L −1 for all types of nanoplastics. These results agreed with previous studies that showed increased mortality (LC 50 40.95 mg L −1 ) of Artemia exposed to higher concentrations (1–100 μg mL −1 ) of PP-MPs 44 and PS-NPs (5–100 μg mL −1 ), 45 as well as PS-NH 2 (100 μg mL −1 ) 22 and PS-NH 2 (10 μg mL −1 ) for 48 h. 6 However, some studies reported no significant effects of MPs on the survival of different brine shrimp species. 23,27,46 This indicates that the size of M/NPs influences the ingestion, bioaccumulation, and survival of brine shrimp.…”

“…49) and 100 mg L −1 PS-NH 2 . 22 Nanoplastics accumulated in the gut and other organs of the nauplii in a concentration-dependent manner (Fig. S1 †) with PS-NPs showing the highest bioaccumulation among the three types.…”

“…13,14 Nanoplastic ingestion has been reported in several marine invertebrate species with significant accumulation of NPs in bivalves 2,15,16 rotifers 17,18 and crustaceans. 19–22 Among crustaceans Artemia, also known as brine shrimp has been widely used as an ecotoxicological model organism in the marine environment due to their short life cycles, and high fecundity. 23 These are small crustaceans inhabiting hypersaline waters, such as salt lakes, lagoons, and salt pans where they serve as a crucial food item for many fish larvae and play a key role in the energy transfer of the marine trophic chain.…”

Sublethal Effects of Polystyrene Nanoplastics on the Embryonic Development of Artemia salina (Linnaeus, 1758)

“…Existing literature has generally signaled sublethal effects related to exposure to polystyrene even at different concentrations and sizes (6-10 µm at a concentration of 2 mg/L) [66][67][68]. Lethal effects have been observed with the use of particles (10 µm) of polyethylene (which, to date, seems to be the most toxic type of plastic in the short term [69]) or nanoparticles for chronic exposure (14 d) to a concentration of 20-50 µg/mL [70,71]. Again, further studies will have to be performed in order to assess the actual exposure conditions of zooplankton in nature.…”

Sustainable PHBH–Alumina Nanowire Nanocomposites: Properties and Life Cycle Assessment

“…Larvae of 24 h post hatching (hph) were harvested and selected for the test under a stereoscopic microscope (Nikon smz800, Tokyo, Japan). Larvae immobilization at 24 and 48 h of exposure was used as a criterion for acute toxicity [26]. At least 5 individuals were transferred and maintained for 48 h in each well of the 24-well polystyrene microplates containing 2 mL of exposure medium.…”