Risk-based integrated framework for evaluating effects of microplastics to aquatic ecosystems and human health.

Area of Science:

• Environmental Science
• Ecotoxicology
• Public Health

Background:

• Microplastics (MPs) are pervasive environmental contaminants with potential risks to aquatic ecosystems and human health.
• Existing risk assessments often rely on single tools, leading to incomplete evaluations of MP impacts.
• A comprehensive understanding of MP risks requires integrated approaches considering both ecological and human health perspectives.

Purpose of the Study:

• To investigate microplastic abundances in Taiwanese estuarine surface water and wild oysters.
• To develop and apply an integrated risk-based framework for evaluating MP exposure and effects.
• To assess aquatic ecological risks, oyster mortality risks, and human health risks from MP contamination via seafood.

Main Methods:

• Quantified microplastic abundances in surface water (items/m³) and wild oysters (items/g wet weight).
• Calculated aquatic ecological risk quotients (RQ) and oyster mortality exceedance risk (ER).
• Assessed human microplastic intake exposure and human liver damage exceedance risk (ER) using probabilistic risk curves.

Main Results:

• Microplastic concentrations ranged from 0.025–4.701 items/m³ in water and 0.015–2.374 items/g in oysters.
• Aquatic ecological risk was generally negligible (RQ values).
• Oyster mortality risk showed a 10% risk with a 6% increase in mortality; human health risk (ALT levels) was low.

Conclusions:

• Single risk indicators may underestimate the potential impacts of microplastics.
• An integrated, multi-faceted risk assessment framework is crucial for evaluating both organismal and human health risks.
• While ecological risks appear low, specific organismal risks (oyster mortality) and potential human health concerns warrant continued monitoring and research.