Picture: ISTOCK
Picture: ISTOCK

Plastic isn’t the problem: the issue is how we design plastic products and dispose of them, a global expert on plastic litter on Tuesday told Europe’s biggest inter-disciplinary science meeting, EuroScience Open Forum 2018. Better design could increase recycling rates and reduce the amount of plastic that ends up in the oceans, where it threatens marine life, said Plymouth University marine biologist Richard Thompson.

Plastic pollution is a rapidly growing global problem, driven partly by the fact that humans have had "60 years of training" to regard most plastic products as disposable items, said Thompson. The impact of this throw-away culture is compounded by poor design that makes products difficult or too expensive to recycle, he said. A simple example of bad design is colourful, single-use bottles: many companies won’t recycle coloured bottles because the pigments they contain are difficult to remove, and can reduce the value of recycling by as much as 50%, he said.

The issues Thompson raised have direct relevance to SA, which is grappling with the environmental threats posed by plastic, including pollution of its beaches and harbours.

The annual global volume of plastic produced has steadily increased since the 1950s, rising from five tonnes to 300, of which 40% is now single-use plastic, said Thompson. "They have a very short life in service, but an incredibly long persistence as waste."

A recent study estimated a cumulative 8.3-billion tonnes of plastic had been produced in the past 60 years, and the figure was projected to rise to 34-billion by 2050.

Thompson said designers were typically briefed to create products that were functional and aesthetically pleasing, but were not asked to ensure they could be viably recycled. Tackling the problem required better collaboration along the entire supply chain, and a closer working relationship between designers and the companies that dealt with waste, he said.

He advocated reducing the diversity of plastics used for similar products, as the sheer variety of polymers, additives and pigments posed challenges for the recycling industry. For example, if beverage manufacturers agreed to all use clear polyethylene terephthalate (PET) to bottle their drinks, it would improve recycling rates.

"It’s not about banning plastics, but using them more responsibly. We can’t legislate against every product," he said, noting that while there were some products people could do without — such as single-use plastic drinking straws and shopping bags — most could not be legislated out of existence. "The systemic change needed is that products need to be designed to be recycled. If the consumer believes in recycling, it is more likely to happen."