How do we stop plastic ruling the waves?
Science Feature by Professor Glenn Patrick
WE have all watched the distressing scenes on television where albatrosses regurgitate plastic debris to feed their young chicks and dead dolphins are found entangled in plastic fishing gear.
Overall, 386 marine species are known to have ingested plastic debris and by 2050 it is estimated that plastics will outweigh the fish in the ocean.
From today’s perspective, it is ironic that the first plastics were developed to improve the natural environment!
In the 19th century, ivory was extensively used in many items like piano keys, hair combs and trinket boxes.
Billiards was a fast-growing activity in both the US and Europe, leading to a huge additional demand for ivory and the mass slaughter of wild elephants – especially in Sri Lanka.
The search for an alternative material to ivory started in 1862 when the Birmingham metallurgist Alexander Parkes created ‘Parkesine’ made from cellulose and nitric acid.
This won a bronze medal at the International Exhibition in London and, although commercial production was unsuccessful, was the starting point of the plastics age.
Meanwhile, with dwindling numbers of elephants and the price of ivory rocketing, an American billiard ball company called Phelan and Collender took out a newspaper advert offering $10,000 to anyone who could find a substitute material.
A New York printer called John Wesley Hyatt began experimenting and after buying Parkes’ patent in 1869 came up with the first commercial man-made polymer, which we know now as ‘Celluloid’.
Although it was not a particularly good material for billiard balls and did not win the prize, Celluloid was successful in other areas including making movie and photographic film – the start of the plastics industry.
As a faux ivory, Celluloid still played its part in saving the elephant and as a substitute for tortoiseshell – much used in combs and as a decorative veneer – also saved the early extinction of the Hawksbill species of sea turtle.
New plastics followed, most notably by the Belgian-American chemist Leo Baekeland. By combining phenol and formaldehyde, in 1907 he made both the first truly synthetic plastic and the first thermosetting plastic called ‘Bakelite’.
A polymer is a long chain molecule consisting of many smaller units – or monomers – that are repeated and joined together in a three-dimensional network.
Thermosets – unlike thermoplastics – undergo an irreversible chemical change that cross-links this network of molecules. This means that they cannot be reused and makes them difficult to recycle.
Bakelite plastic had the right properties for billiard balls and by the 1920s most of them were made from it rather than ivory – saving the elephant.
Plastic is an umbrella term covering all synthetic polymers with the word coming from the Greek and Latin words ‘plastikos’ and ‘plasticus’, meaning something that can be easily moulded or shaped.
These days, we exploit many synthetic polymers and use plasticizers to make them softer and more flexible. We usually know them by their acronyms – for example PVC (polyvinyl chloride) and PET (polyethylene terephthalate).
The adaptability of plastic means that it is now used everywhere – in our houses, in our cars, in our clothes and to package the things we buy.
Sadly, due to its structure, it also means that we end up with plastic litter and long-lived waste in our eco-systems.
At the end of the 20th century, an ‘out of sight, out of mind’ policy prevailed with the export of plastic waste from developed to developing countries.
China was not only the largest plastic producer in the world, but was also eventually importing 56 per cent of the world’s plastic waste with consequent environmental problems.
Those of us who watched the TV documentaries of Hugh Fearnley-Whittingstall – of River Cottage fame – will not forget the images of UK-branded debris amongst the mountains of plastic waste at recycling plants in Malaysia.
This global chain of waste processing had become part of the problem rather than the solution. This changed in 2017 when China banned the import of certain types of plastic waste throwing the spotlight back onto the domestic activities of local authorities.
The UK uses an estimated five million tonnes of plastic every year – about half of which is packaging.
Several initiatives have been implemented to reduce the impact of plastic like banning the sale of plastic straws, cotton buds and stirrers in October 2020.
From 2022, the UK government will also charge £200 per ton for any plastic packaging that does not contain at least 30 per cent recycled plastic, but much more needs to be done.
Living by the English Channel, it is not difficult to be aware of the impact of coastal plastic pollution on our shorelines. It is easy to think of this as a local problem, but ocean currents can circulate debris from much further afield.
The UK recycling rate for plastic is estimated, perhaps optimistically, to be 46%, but worldwide it is only about 9% – and that is a big problem. Every minute, the equivalent of a garbage truck full of plastic is dumped into our oceans.
To make matters worse, the COVID-19 pandemic triggered the production of billions of face masks and gloves every month, and we have all seen them carelessly discarded.
It has been projected that, if stitched together, the face masks from the pandemic would cover the entire landmass of Switzerland!
The largest source of plastic leakage into the oceans (82%) is attributed to a small number of Asian and Pacific Rim countries. Moreover, around 90% of the waste is thought to be transported from land-based sources into the oceans by just ten rivers – none of them in Europe.
We cannot be smug in the UK though. It is our insatiable demand for plastic and the mismanagement of its waste that has contributed to this situation.
So, what are we to do?
The Ellen MacArthur Foundation works to promote a circular economy where we move away from the wasteful single-use model to a circular plastic economy where products are designed so that materials are recirculated and reused without them escaping into the environment.
There is no single solution – it is a combination of eliminating the plastics we do not need, finding new materials, ensuring the plastics that we do use are reusable, recyclable, or compostable and that we protect our natural systems from contamination.
We must take care though that we find long-term solutions to our throw-away society and learn the lessons of what happened with ivory back in the 19th century.
Professor Glenn Patrick is a particle physicist and science communicator who explores the quantum world of sub-atomic particles (including at the Large Hadron Collider) and now lives in Lyme Regis.