Understanding our plastics problem

A new report by Royal Society Te Apārangi explores the use and disposal of plastics and the effects on the environment and human health in Aotearoa.

The report Plastics in the Environment: Te Ao Hurihuri – The Changing World sets out how plastics are made, used and disposed of. It outlines how plastics enter and accumulate in the environment, and the risks posed to wildlife and humans.

“We are publishing this report to raise awareness of the extent of the issue of waste plastics and to provide information to help us collectively figure out how we can turn the issue of plastic pollution around in Aotearoa,” Royal Society Te Apārangi President Professor Wendy Larner said.

“It complements a report on policy options and potential actions due out later in the year from Professor Juliet Gerrard’s Office of the Prime Minister’s Chief Science Advisor.”

New Zealand has a high per-capita use of plastics and, like the rest of the world, we are witnessing large amounts of plastic pollution, even in remote places like Stewart Island’s Mason Bay.

Most plastic is produced from fossil fuels, consuming 4–8% of global oil production. The amount of plastic produced each year has doubled over the last 20 years and is still growing rapidly, despite growing concerns about plastic pollution and climate change.

“We have all seen the piles of plastics in rivers and on beaches or seen images of the immense ocean garbage patches. Through reading this report, it is incredible to learn that we have only been creating plastics in any quantity since the 1930s.

“Now plastics are foundational to nearly every aspect of modern life, from construction to clothing, food distribution and healthcare. Plastic has many desirable properties that can reduce transportation costs and can ensure safe food and healthcare, as examples. But clearly we can no longer continue to produce and use it in the way we have been,” Professor Larner said.

The report outlines that we have thrown away three quarters of the volume of plastics ever produced. Less than 20% of the waste plastic generated each year is recycled worldwide. Of the remainder about 70% goes to landfill and 30% is incinerated.

Badly managed waste plastics from littering, illegal dumping or escaping from landfills are significant sources of plastic entering the environment, and there is growing concern about hidden forms of pollution such as the plastic waste that is produced from the fibres that come off our synthetic clothing when we wash them or from tyre dust from vehicles.

Much of this waste plastic is entering our oceans, says environmental chemist Associate Professor Sally Gaw from the University of Canterbury, who contributed to the report.

“It has been estimated that the equivalent of a garbage truck-load of plastic waste has been dumped into the ocean every 38 seconds over the past decade. Unless we do something, it is estimated that by 2050 there will be more plastic than fish in the ocean.

“In addition to entrapping and killing animals, plastic waste in the ocean can provide rafts for invasive species to move around the world and plastic debris has also been associated with decreased health of coral species. However, most of the concern is now focussed on microplastics,” she said.

The problem with most of today’s plastic waste in the environment is the conditions don’t allow for the plastics to break down into their constituent materials, carbon dioxide and water, which could then be used as a food source or building blocks for organisms to grow.

“This means that the majority of waste plastic that enters the environment remains as waste plastic. Ocean waves, sunlight or abrasion from sand or rocks can break the plastic into smaller and smaller fragments that can then be ingested or breathed in by wildlife on land or in the sea. Humans are also consuming microplastics.

“Researchers are still determining the full impact of this plastic entering the food chain but evidence is mounting that there is good reason for concern, especially as some plastics can contain toxic chemicals,” Associate Professor Gaw said.

So what can be done to reduce plastic pollution?

“The limitations on the number of times that plastic can be recycled and the difficulties of recycling products made of different types of plastics means many are calling for a radical shake up of how we design, produce, use and consider the end of life for plastics”, says Dr Elspeth MacRae, Chief Innovation and Science Officer at Scion.

Dr Florian Graichen from Scion recently attended an international meeting on switching to a circular economy approach. “An integrated circular economy focusses on six guiding principles – refuse, re-use, reduce, redesign, recycle and renew - rather than disposal. This mitigates the environmental issues and reduces the demand for new plastic production from oil, which could be met through renewable feedstock.

“Attending this event was heartening because there were a number of major international companies there who see that there is no option other than to adopt such an approach, both for business and the health of our planet. Plastic production could represent 15% of the global carbon budget by 2050 if we don’t change our approach. Plastic recycling needs to become about carbon recycling.

“From New Zealand’s perspective, there is also an opportunity for us to contribute bio-based products into this new approach and be at the forefront of innovation in this area,” he said.

The report will be available to view at royalsociety.org.nz/plastics.

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