Marine Biodegradability and Toxicity of Commercially Available Biobased Plastics -A Sustainable Alternative To Petrochemical Plastics?

Marine Biodegradability and Toxicity of Commercially Available Biobased Plastics -A Sustainable Alternative To Petrochemical Plastics? I. Halvorsen Verpe, Aalborg University / Department of Chemistry and Bioscience; P. Roslev, Aalborg University / Biology and Environmental Science The presence of conventional petroleum-based plastics in marine ecosystems is of increasing global concern. Slow biodegradation and ingestion of plastics and microplastics may result in adverse effects in marine organisms from different trophic levels. More easily biodegradable plastics produced from biobased sources have been proposed as alternatives. Global production of new bioplastics is therefore increasing but there is often limited knowledge about the fate and effects in marine environments. In this study, we studied the aerobic biodegradability of several new bioplastic polymers in seawater and compared with conventional petrochemical plastics (e.g., PE and PET). The study also included a comparison of degradability and toxicity of microplastics (< 100 µm) originating from conventional plastics and microplastics originating from biobased plastics (“microbioplastics”). Biodegradability of plastics in seawater was measured by RAMAN spectroscopy and as O2 consumption and CO2 production. Fiber-optic oxygen sensors were used to study aerobic biodegradation in sediments. Marine ecotoxicity was examined by measuring inhibition of the marine bacterium Aliivibrio fischeri and the marine rotifer Brachionus plicatilis. The study showed significant differences in biodegradability and toxicological signature of commercially available biobased plastics. Hence, it is important to examine the fate of novel polymer innovations in different environments and under different environmental conditions to select the most eco-friendly alternatives and avoid large scale release of unsuitable products.