Weathered polyethylene microplastics induced immunomodulation in zebrafish.

Area of Science:

• Environmental Toxicology
• Aquatic Biology
• Ecotoxicology

Background:

• Microplastics (MPs) are pervasive aquatic pollutants.
• Aquatic organisms unintentionally ingest MPs, leading to adverse effects.
• Understanding MP toxicology is crucial for ecosystem health.

Purpose of the Study:

• To investigate the immunological and haematological effects of weathered polyethylene (wPE) MPs on Danio albolineatus.
• To assess the impact of chronic, sublethal MP exposure on fish health markers.

Main Methods:

• Danio albolineatus were exposed to a sublethal concentration of fragmented wPE MPs (1 µg/L) for 40 days.
• Control and exposure groups were established for both sexes.
• Immunological markers (lysozyme, antimicrobial, antiprotease activity) and haematological differential counts were analyzed.

Main Results:

• Exposure to wPE MPs caused significant alterations in lysozyme, antimicrobial, and antiprotease activity.
• Differential blood cell counts were significantly modified in exposed fish.
• Male fish exhibited higher susceptibility to MP-induced effects compared to females after 40 days of exposure.

Conclusions:

• Chronic exposure to weathered polyethylene microplastics affects the immune and haematological status of Danio albolineatus.
• Sex-specific differences in susceptibility to microplastic pollution were observed, with males being more vulnerable.
• Further research is required to fully elucidate the complex immune responses to microplastic exposure in fish.