Microplastics as Dual-Origin Contaminant Vectors: Leaching, Sorption Dynamics, and Combined Biological Impacts

Dear Colleagues,

Microplastics (MPs) are increasingly recognised not only as physical pollutants but as dynamic chemical carriers capable of transporting contaminants from two distinct origins. MPs release intrinsic chemical additives incorporated during manufacturing while simultaneously acquiring extrinsic environmental pollutants through sorption processes. Understanding how these two contaminant pathways operate (independently and in combination) is essential for accurately assessing ecological and human-health risks.

This Special Issue focuses explicitly on intrinsic additive leaching, extrinsic contaminant sorption and desorption, and the interactions between these pathways as microplastics age and transform in the environment. Weathering processes, such as UV exposure, oxidation, fragmentation, and biofilm formation, can substantially modify microplastic surface chemistry, altering both leaching rates and sorption capacity. These transformations generate real-world chemical mixtures on microplastic surfaces, combining additives, POPs, heavy metals, pharmaceuticals, PFAS, and other emerging contaminants into complex, mobile chemical cocktails.

A central aim of this Special Issue is to examine biological impacts driven specifically by the chemical load carried by microplastics themselves. We encourage studies addressing how chemically burdened MPs release contaminants during ingestion, drive bioaccumulation and trophic transfer, induce mixture toxicity, or influence metabolic, endocrine, immunological, and microbiome-related pathways.

In this Special Issue, original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:

1. Leaching behaviour of intrinsic additives under environmental conditions.
2. Sorption–desorption mechanisms for POPs, metals, pharmaceuticals, PFAS, and other pollutants.
3. Weathering-driven changes in contaminant mobility and microplastic surface chemistry.
4. Formation, characterisation, and toxicity of real-world contaminant mixtures on MPs.
5. Trophic transfer, biological uptake, and organism-level effects driven by chemical release.
6. Comparative studies of intrinsic vs. extrinsic contaminant pathways.
7. Ecological and human health risk implications of chemically loaded microplastics.

We look forward to receiving your contributions.

Dr. Mukhtiar Ali
Dr. Sungwoo Bae
Prof. Dr. Jiangyong Hu
Guest Editors

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• contaminant vectors
• intrinsic additives
• contaminants sorption
• environmental transport
• bioaccumulation
• toxicity
• environmental health
• PFAS
• ecological impact