Microplastics Decrease the Toxicity of ¹³⁷Cs in the Zebrafish Embryo-Larva

Area of Science:

• Environmental Toxicology
• Ecotoxicology
• Aquatic Toxicology

Background:

• Radionuclides and microplastics (MPs) are prevalent environmental contaminants.
• Their combined toxicological risks in aquatic ecosystems are poorly understood.
• Understanding co-exposure effects is crucial for ecological risk assessment.

Purpose of the Study:

• To investigate the toxicological effects of ¹³⁷Cs and PS-MPs co-exposure on zebrafish embryos.
• To elucidate the underlying mechanisms of toxicity and potential interactions.
• To assess the ecological risks associated with these co-contaminants.

Main Methods:

• Zebrafish embryos were exposed to ¹³⁷Cs and polystyrene MPs (PS-MPs) for 7 days.
• Developmental endpoints (hatching, behavior) and transcriptomic profiles were analyzed.
• KEGG enrichment analysis identified affected biological pathways.

Main Results:

• ¹³⁷Cs exposure significantly impaired zebrafish development, causing delayed hatching and altered swimming behavior.
• Transcriptomic analysis revealed widespread gene expression changes in ¹³⁷Cs-exposed groups, particularly affecting lipid metabolism.
• MPs showed a potential protective effect by absorbing ¹³⁷Cs, reducing internal irradiation and toxicity.
• ¹³⁷Cs-induced lipid metabolism toxicity may explain neuro-related gene alterations and behavioral abnormalities.

Conclusions:

• Combined exposure to ¹³⁷Cs and MPs presents complex ecological risks.
• ¹³⁷Cs induces developmental and behavioral toxicity in zebrafish via lipid metabolism disruption.
• MPs may mitigate ¹³⁷Cs toxicity through radionuclide absorption during early development.
• Further research is needed to fully understand the long-term implications of these co-contaminants.