The field of micro and nanoplastics research is still developing, with standardized research protocols and communication yet to come to a scientific consensus (FPF reported). The research around bioplastic particles is newer still.
Udara Piyathilake from the National Institute of Fundamental Studies in Sri Lanka and co-authors set out to summarize what has been researched so far in this sub-field of microplastics research. Their literature review investigated multiple avenues of micro- and nano(bio)plastics (MNBs) research published since 2012 including degradation pathways, toxicity, interactions with hazardous contaminants, and research gaps. Overall, “[t]he general belief that ‘biodegradable’ always implies complete biodegradation is questionable.”
Bioplastics and other polymers can degrade in many ways including through mechanical, thermal, chemical, bacterial, and fungal methods. Piythilake et al. discuss the research that has gone into our understanding of each degradation pathway but in nearly every case they highlight many situations that still need investigating – e.g., degradation in natural environments, alternate pH soils, differences in salinity, and local bacterial communities (FPF reported, also here).
About 20% of the approximately 250 MNB studies they reviewed included toxicological experiments, with the majority of those investigating soils. “The findings reveal a spectrum of toxicological impacts, ranging from seemingly minor growth inhibitions to more severe issues affecting digestive systems, endocrine systems, immune systems, reproductive capabilities, metabolism, and even mortality.” Even with this range of impacts, the authors highlight that the majority of studies focused on short-term exposures, “with the long-term effects of chronic exposure being less understood.”
Nineteen studies in the review mention substances released into the environment from MNB degradation including heavy metals, plasticizers, antioxidants, volatile organic compounds, and others (FPF reported, also here).
In every section the authors highlight research gaps and like others in the larger microplastics field they encourage researchers to “strive for transparency in reporting methodologies and results to facilitate collaboration and cumulative knowledge in the field of micro- and nano-bioplastics.”
The Food Packaging Forum has published a fact sheet on bioplastic food packaging addressing common questions and mix-ups.
Reference
Piyathilake, U., et al. (2024). “Exploring the hidden environmental pollution of microplastics derived from bioplastics: A review.” Chemosphere. DOI: 10.1016/j.chemosphere.2024.141773
Other recent research on (micro)bioplastics
Ghasemlou, M., et al. (2024). “The future of bioplastics in food packaging: An industrial perspective.” Food Packaging and Shelf Life. DOI: 10.1016/j.fpsl.2024.101279
Mut, N.N.N, et al, (2024). “A review on fate and ecotoxicity of biodegradable microplastics in aquatic system: Are biodegradable plastics truly safe for the environment?” Environmental Pollution. DOI: 10.1016/j.envpol.2024.123399
