Nanoplastics Decrease the Toxicity of a Complex PAH Mixture but Impair Mitochondrial Energy Production in Developing...

Area of Science:

• Environmental Toxicology
• Nanotoxicology
• Ecotoxicology

Background:

• Micro- and nanoplastics are emerging environmental contaminants.
• These particles can interact with organic pollutants, potentially altering their toxicity.
• The combined effects of nanoplastics and environmental contaminants on aquatic organisms require investigation.

Purpose of the Study:

• To investigate the toxicity of polystyrene nanoparticles (Nano-PS) and a polycyclic aromatic hydrocarbon (PAH) mixture (ERSE) to zebrafish embryos and larvae.
• To evaluate the effects of coexposure to Nano-PS and ERSE on zebrafish development and physiology.
• To understand the interaction between Nano-PS and PAHs and its impact on contaminant bioavailability and toxicity.

Main Methods:

• Zebrafish embryos and larvae were exposed to Nano-PS, ERSE, or a combination of both.
• Developmental endpoints, including malformations and vascular development, were assessed.
• PAH bioaccumulation, EROD activity, and mitochondrial function (coupling efficiency, NADH production) were measured.

Main Results:

• ERSE exposure caused significant developmental defects and impaired vascular development in zebrafish larvae.
• Coexposure to Nano-PS reduced ERSE-induced developmental toxicity and vascular impairment.
• Nano-PS exposure alone or in combination with ERSE impaired mitochondrial function, decreasing coupling efficiency and increasing NADH production.

Conclusions:

• Nanoplastics can sorb environmental contaminants like PAHs, reducing their bioavailability and toxicity.
• Nanoplastics can independently disrupt mitochondrial energy metabolism in aquatic organisms.
• The combined effects of nanoplastics and contaminants on energy metabolism may have significant ecological implications, especially under multi-stressor conditions.