Biodegradable Plastics: Environmental Impacts And Waste Management Strategies

Monday, October 15th, 2018

Tony Seers from the Australian Institute of Packaging and Australasian Bioplastics Association explores the ramifications of bioplastics disposal within marine environments and strategies towards proper waste management practices. 

According to The Australian Standard,  ‪AS4736, biodegradable bioplastics are only “compostable” or “biodegrable” in terrestrial landscapes, and are most suited for biodegradation within industrial environments. However, they are not adapted for biodegradation in other environments such as the marine ecosystem. This is because for biodegradation to occur optimally, a healthy microorganism population, high oxygen levels and warmer temperatures are required  but within the marine environment, variations in oxygen levels, temperature, microorganism populations and tidal movements are present. This significantly slows down or completely stops the biodegradation process, especially because microorganism levels are much lower in the marine environment than in terrestrial conditions or a compost heap.

The role that microorganisms play in the degradation cycle is essential and includes the consumption of waste materials by the microorganisms present and the generation of carbon dioxide, water and biomass in the process. Therefore, when microorganism levels are low or when external conditions disrupt microorganism activity, microfibres from waste materials will remain in the marine environment for months or an even longer period before it can biodegrade. This means that in the case of plastics disposal, whether the plastic is derived from plants, fossils, classified as degradable or non-degradable, it should not be disposed in the ocean and waste management and recycling practices should be highlighted as a key solution to prevent this. This can be achieved by educating the public in order to inculcate a behavioural change when it comes to recycling and waste disposal or even advocating engineering innovations in the areas of filtration, screening and the formulation of products. Further research as well as modifications to bioplastic product designs can also aid in deceasing the negative impacts of marine litter in the event that waste management practices are insufficient.