Various additive release from microplastics and their toxicity in aquatic environments

Area of Science:

• Environmental Science
• Polymer Science
• Ecotoxicology

Background:

• Additives constitute a significant portion of plastic composition, often exceeding 50%.
• These additives can leach from microplastics (MPs) into aquatic ecosystems due to aging and fragmentation.
• Some additives are hazardous, presenting ecological risks and toxicity to aquatic organisms.

Purpose of the Study:

• To summarize the application and environmental leaching of functional additives in MPs.
• To review the release mechanisms and influencing factors of additives from MPs.
• To discuss the toxicity effects and challenges in assessing human health risks from MP-associated additives.

Main Methods:

• Literature review on additive leaching from MPs.
• Analysis of release mechanisms (photooxidation, chemical oxidation, biodegradation, abrasion).
• Review of factors affecting additive release (particle size, light, temperature, DOM, pH, salinity).

Main Results:

• Additives release is promoted by smaller particle size, light, high temperature, DOM, and alkaline conditions.
• Polymer structure, electrolytes, and salinity also influence additive release.
• Leached additives can be ingested by organisms, causing developmental issues and toxicity.

Conclusions:

• Challenges remain in assessing the toxicity and human health risks of MP additives.
• Future research should focus on realistic leaching experiments, improved analytical methods, and broader toxicity evaluations.
• Understanding MP additive release is crucial for environmental risk assessment.