Co-exposure to microplastic and plastic additives causes development impairment in zebrafish embryos

Area of Science:

• Environmental Toxicology
• Developmental Biology
• Ecotoxicology

Background:

• Microplastic and plastic additive pollution in aquatic environments is a growing concern.
• Understanding the combined toxicity of these pollutants is crucial for assessing ecological risks.

Purpose of the Study:

• To investigate the adverse effects of co-exposure to microplastics and plastic additives on zebrafish embryonic development.
• To elucidate the combined effects of microplastic-additive mixtures on zebrafish embryos.

Main Methods:

• Zebrafish embryos were exposed to binary and ternary mixtures of polystyrene (PS), bisphenol S (BPS), and mono-(2-ethylhexyl) phthalate (MEHP) at non-toxic concentrations.
• Phenotypic toxicity and changes in transcription levels of genes related to cell damage and thyroid hormone synthesis were analyzed.

Main Results:

• Mixtures induced significant phenotypic toxicity in zebrafish embryos, with synergistic effects observed for BPS and MEHP combinations.
• Exposure to ternary mixtures at low, non-toxic concentrations altered gene expression, down-regulating cell damage and thyroid hormone synthesis genes while up-regulating cyp1a1 and p53.

Conclusions:

• Microplastic-additive mixtures can cause embryonic damage and developmental malformations in zebrafish, even at low concentrations.
• The findings provide insights into the mechanisms of developmental toxicity induced by microplastic-additive mixtures.