Human Practices

Introduction

A current and prevalent issue in society is the major use of plastic and its resulting consequences of plastic pollution. Plastic pollution starts when the plastic trash on land is carried to the sea, starting from the rivers and eventually reaching the oceans, where the plastic remains and is transported around the world (Ritchie, 2021). About 29,000 tons per year of plastic leak into the environment with about 2.8 million tons of plastic going to these landfills (Statista Research, 2023). The plastic then accumulates as it can take about 400 years to break down due to the additives added to give plastic an extended life. Not all plastic is recyclable, however, PET plastic - a plastic made of polyethylene terephthalate - is. It is not only 100% recyclable but is also durable, lightweight and inexpensive, making it a convenient and popular material to use. In fact, most of this plastic is used for packaging with plastics occupying around 31% of packaging material usage (Topic, n.d) such as for protecting and preserving products to keeping sterility in hospitals. Due to this popularity, about 460 million tons of plastic are used in the world per year, leading to many harmful effects due to its unbiodegradable characteristics - meaning it does not break down easily into the environment. This resulting pollution caused by PET plastics can then exert further negative effects on the environment such as soil pollution caused by plastic chemicals leaching into soil, the negative impacts of recycling plastics and the consumption of micro-plastics which harms wildlife (Plastic Planet, n.d). One strategy to alleviate these impacts is replacing PET with PHB (Polyhydroxybutyrate), a plastic alternative that is produced by bacteria and can be degraded by a variety of other microbes, making it biodegradable (Team, 2023). As it degrades quickly in natural environments, when PHB plastic is thrown out, plastic pollution is thus limited. Some limitations to PHB include its physical characteristics such as having more brittle and less flexibility, as well as being more expensive to PET plastics and thus, having more limited applications (Adnan, 2022). However, creating a blend of PHB and other plastics can overcome PHB's mechanical characteristics and increase its application use (Adnan, 2022). In addition, despite PHB's limitations, the overwhelming increase in plastic use and thus plastic pollution still makes PHB a better plastic alternative to PET plastic.

Figure 1. When PET plastic nears the end of its life cycle, it is often not recycled (pink) and ends up in landfills or in the environment. Using PHB to replace it could lessen the negative effects of products ending up outside of the recycling pathway.

Impact on the Current Recycling Process

With the amount of plastic waste produced in Canada, the current recycling process is inefficient with only 9% of plastic being recycled, while the rest resides in landfills or the environment (Canada, 2023). This is due to many reasons such as there being such a big variety of different types of plastics that increases the complexity of the process as well as the inability to recycle some types of plastics due to their toxicity risks. In addition, due to the many stages of plastic recycling - collecting, sorting, transporting and reprocessing - it is not economical as it costs more to recycle plastics than to make more (Judith, 2022). Methods used to recycle plastics can also cause additional environmental issues such as microplastic pollution and carbon emissions from the melting process. For this reason, we need a more efficient and environmentally friendly method for recycling plastic.

References

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