Ecotoxicology and the Fate of Contaminants in the Circular Economy

Dear Colleagues,

The presence and fate of chemical contaminants in recycled goods pose a significant challenge to the sustainability of the circular economy. Secondary raw materials may accumulate these substances at higher levels than their virgin counterparts, as these chemicals are often not removed by conventional recycling processes. This can potentially increase risks to human health and ecosystems.

Examples include heavy metals, per- and polyfluoroalkyl substances (PFAS), legacy and novel flame retardants, bisphenols, and various paper, plastic, and textile additives, many of which still lack comprehensive hazard characterization. Among them, micro- and nanoplastics can also be considered.

A key challenge in this field is the lack of standard methods for reliably quantifying the presence of contaminants in secondary raw materials and their migration to the exposed environmental median and receptors. The complexity and heterogeneity of these materials, combined with the diverse chemical nature of contaminants, necessitate the development of harmonized methodologies to ensure comparable data for risk assessment. Furthermore, exposure assessments should align as closely as possible with the intended use (or ultimate fate) of recycled materials, balancing hazard-based and risk-based approaches towards more realistic risk estimates.

Addressing these gaps is therefore crucial to the following:

• Understanding the presence of contaminants in the circular economy, their behaviors, and their exposure pathways to humans and ecosystems;
• Supporting science-based regulatory decisions in this field.

This Special Issue on ‘Ecotoxicology and the Fate of Contaminants in the Circular Economy’ aims to compile innovative research on the monitoring, ecotoxicological characterization, and environmental fate of contaminants and Non-Intentionally Added Substances (NIAS) in secondary raw materials and recycled products.

Suggested topics include, but are not limited to, the following:

• Advancements in analytical strategies for the quantification of contaminants in secondary raw materials;
• The presence and distribution of contaminants in secondary raw materials and recycled products;
• The transformation, degradation, and fate of contaminants during recycling processes;
• Experimental or modeling approaches to assess their related health and environmental risks;
• Migration potential, considering the intended use of the secondary raw materials;
• Bioavailability, phytoavailability, and translocation studies focusing on these contaminants;
• Ecotoxicological studies considering environmentally relevant concentrations.

Studies investigating recycled biobased materials are welcome. However, studies focusing on contaminants in recycled products intended for agricultural use (e.g., fertilizers and soil amendments from agro-food residues, biowaste, manures, and sewage sludge) will not be considered in the scope of this Special Issue.

Dr. Giovanni Beggio
Dr. Tiziano Bonato
Guest Editors

Manuscript Submission Information

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• circular economy
• recycled products
• recycled plastics
• textiles
• construction and demolition waste
• end of waste
• waste recycling
• waste recovery
• emerging contaminants (CECs)
• non-intentionally added substances (NIAS)
• secondary raw materials
• migration
• exposure characterization
• bioavailability
• ecotoxicology