Ending the age of plastic
As plastic pollution covers the globe, can science provide solutions? Michael Lucy investigates.
They look quite natural in the sand. Lentil-sized white blobs, sometimes a little translucent, not quite perfectly round: they might be milky pebbles or moonlit grains of rice, and they blend in smoothly with the seaweed and shells left on the shore by the tide. It isn’t hard to see why birds mistake them for fish eggs and gulp them down.
Nurdles, as they are disarmingly called, are pellets of plastic resin, the raw material shipped to manufacturers making plastic goods, and I am searching for them on a foggy midwinter morning at Shelly Beach in southeastern Australia, a seemingly pristine cove where endangered hooded plover nest among the rocks and waves roll in off water that stretches a clear 3,000 km to Antarctica.
My nurdle-hunting teacher and guide, Colleen Hughson, holds up several examples for inspection. Hughson is a filmmaker and producer who lives nearby in the town of Warrnambool. She has become something of an expert since nurdles began washing up on Shelly Beach in the hundreds of thousands in November 2017.
It takes a minute or two sifting through the sand and several false starts before I find my own: first a smooth speck of pumice, then two shell fragments, and finally a nurdle. Once I have my eye in I spot nurdles everywhere, tiny monuments to human endeavour that might live on here for centuries.
When Hughson first saw the nurdles, she says the whole beach “was just covered”. She had started a Facebook group of volunteers to tidy up litter on beaches around Warrnambool, inspired by the efforts of environmentally minded surfers who set out to protect the world-famous Bells Beach 180 km to the east. One Sunday she got a call from a member of the group who told her Shelly Beach was awash in plastic beads. “So I went down there the next morning to have a look.”
Over the next few days the lightweight, highly buoyant nurdles washed up along a 30 km stretch of coast. Hughson contacted the Victorian Environmental Protection Authority, as well as Wannon Water, the local water authority in charge of an outlet for treated sewage and waste water that discharges into the sea near Shelly Beach. The event was declared a state emergency.
The outlet was quickly confirmed as the source. An unknown quantity of pellets – perhaps more than 4 million – had been dumped into a “sludge acceptance point” near Warrnambool Golf Course by a truck that collects the contents of septic tanks and other waste. The sewage treatment system was designed to catch objects sized down to 6 mm. About 3 million nurdles were caught inside the plant, but many slipped through, going down the pipe and out to the sea.
No one knows how the nurdles got into the septic tank in the first place, or if they do they’re not talking. Wannon Water’s investigation narrowed it down to 20 suspects, but remains open.
As difficult as nurdles are to clean up, an estimated 570,000 were recovered from the coast over several months. An unknown number remain at large. Storms regularly churn up more from deep in the sand.
Now, more than six months later, after sifting through the sand for about 15 minutes we – mostly Hughson, whose sense for nurdles is unerring – collect a handful of nurdles and some other plastic debris.
The pollution feels particularly stark against the apparent isolation and purity of Shelly Beach, which Hughson describes as “the beach you come to if you don’t want to see anyone”. In Warrnambool, a town of 35,000, that’s saying something. But no place is isolated enough to avoid plastic now. Mount Everest is littered with water bottles; the Mariana Trench, the deepest spot in the oceans, is strewn with plastic bags. Microplastic fragments dot the Arctic ice and remote South Pacific island beaches are covered by a tide of trash. The problem is everywhere.
More than 8 billion tonnes of plastics have been produced since the 1950s, and most of that has been thrown away. By 2050, on current trends, plastic manufacturing will account for 20% of global oil use and 15% of carbon emissions. But arguably the most devastating environmental impact is caused by the amount of plastic waste washed into waterways and ultimately out to sea. More than 8 million tonnes ends up in the oceans each year, and that number too is growing exponentially. By mid-century it is estimated the amount of plastic in the world’s oceans will outweigh all the fish.
The millions of bottles and other plastic items that wash up on remote beaches are just the most visible tip of the plastic berg. Bags, straws and wrapping strangle fish, turtles and birds. Of greater concern is what happens to plastic exposed to the elements. Plastic is not biodegradable but it is photodegradable: sunlight breaks it down into progressively smaller pieces. These fragments turn the ocean into a plastic-laced soup, its morsels slowly sinking to the bottom or eaten by fish. Mistaken for plankton, they are devoured by everything from krill to whales. This poses health dangers not only to those animals but to the entire food web, including humans.
The plastics themselves can contain toxins – often additives such as phthalates and bisphenol-A, which are used to change the properties of the plastic, but may be “endocrine disruptors”, which have undesirable hormonal effects on animals. Floating plastic particles can also behave like sponges, soaking up pollutants in seawater and delivering a concentrated dose to whatever is unlucky enough to eat them.
Human intake of microplastics is already widespread. The health impacts are still unknown but in 2017 a British Medical Journal editorial declared it “time to pull our heads from the sand” regarding the risks.
The nurdle I held in my hand at Shelly Beach, gave me a small grip on a problem of unfathomable dimensions. Thought it weighs a fraction of a gram and is worth around a thousandth of a cent, it will no doubt outlive me.
It sits on my desk as I wonder: can science, which created plastic, also provide solutions?
FROM THE CARBONIFEROUS TO THE ANTHROPOCENE
The nurdles at Shelly Beach are tiny lumps of polypropylene, the second most common kind of plastic, after polyethylene.
Like most plastics they are made from petroleum byproducts, which means their story likely began hundreds of millions of years ago, when algae or zooplankton died and settled to the bottom of the ancient ocean. As sediment collected above, the heat and pressure grew and the sludgy mixture formed a solid substance called kerogen, made up of both organic and mineral material. Millions of years passed and the kerogen sank deeper into the Earth’s crust, where more heat and pressure slowly transformed it into the hydrocarbon slurry we know as petroleum. There it sat as the ages went by, until humans appeared on the surface above and developed the tools to tap its chemical properties.
In the 19th century, the aftermath of the industrial revolution saw a demand for new materials – at first as substitutes for rare or expensive materials like ivory – and the scientific and manufacturing know-how to make them mass commodities. The first widely available plastic, celluloid, was plant-derived, made from a nitrocellulose and camphor resin. Patented in 1869 by an American inventor named John Wesley Hyatt, celluloid was designed to win a prize offered by a billiard-table manufacturer seeking a synthetic replacement for ivory billiard balls. Celluloid did the trick, though it was not without its drawbacks: as Hyatt recalled in 1914, “occasionally the violent contact of the balls would produce a mild explosion like a percussion guncap”. (Nitrocellulose is highly explosive.)
Worldwide production of plastics was 2 million tonnes in 1950. In 2017, it was 400 million tonnes.
Nonetheless the age of plastic had begun. As oil extraction grew in the second half of the century (in 1859 US oil production was 2,000 barrels, by 1899 it was 57 million), to provide fuel oil and kerosene, chemists turned to petroleum as a source of the raw molecules that bind together into the long chains of carbon and hydrogen which give plastics their characteristic combinations of malleability and toughness.
By the 1940s, plastics were becoming part of everyday life. They were in the celluloid film that made motion pictures possible, in the ubiquitous Art Deco Bakelite jewellery, in the cheap toothbrushes in any corner shop. According to a 1941 article in Harper’s Magazine, they were “wonder materials” made from “such simple ingredients as air, coal and water”.
It was World War II that really helped plastics come into their own. As metals and other materials were requisitioned for military use, manufacturers sought alternatives. Nylon, for instance, became popular for stockings because all the silk was going to make parachutes. The military also embraced plastics for their desirable properties of strength, heat resistance, electrical insulation and flexibility.
By 1955 disposable and single-use plastics were celebrated. A LIFE magazine article titled ‘Throwaway Living’ showed a family joyfully tossing away food containers, vases, curtains, nappies, and dozens of other items in a modern triumph over the drudgery of cleaning and reuse.
Worldwide production of plastics quadrupled from 2 million to 8 million tonnes a year in the 1950s. By 1970, it was 35 million tonnes. In 2017, it was 400 million tonnes. Production is estimated to continue doubling every dozen years. Of the 8 billion tonnes of plastic produced in the past seven decades, more than half has been produced in the past two. Of that, 30% is still in use, about 10% has been incinerated and almost 60% has ended up in landfill or as litter. And because humans tend to live near waterways, a significant percentage of that plastic litter gets washed into rivers and the ocean – some 80% of ocean plastic arrives this way. The rest is what’s tossed out of boats.
With discarded plastic now forming a thickening skin over the planet, the presence of plastics has been proposed as one of the key markers of the Anthropocene, the present epoch in which the planet has been unmistakably transformed by human activity. Indeed, archaeologists are already using strata of different kinds of plastic polymers to establish eras.
How long plastic particles will stay in the environment is unknown, says oceanographer Juliana Assunção Ivar do Sul of the Leibniz Institute for Baltic Sea Research in Germany. She is the plastics expert in the Anthropocene Working Group of the International Commission on Stratigraphy, which sets the official names and boundaries of periods in the deep history of Earth.
“Once plastic is deposited in sediment we know it degrades very slowly,” she says.
WHAT CAN BE DONE?
Just as there is no single “cure for cancer”, there is unlikely to be a single cure for plastic pollution. Plastics comprise hundreds of materials used for thousands of purposes, from construction and medicine to ultra-disposable packaging, and they fall into the environment along millions of pathways.
If plastic waste ends up in landfill, or even in an informal dump, it may do no great environmental harm. Effective rules and regulations around littering and waste management can therefore make a difference. Recycling can also help, but so far has only captured about 7% of the total plastic produced. Besides, the mechanism many wealthy nations have used for decades to make their recycling regimes economical – exporting the plastic to China, which has historically dealt with almost half of the world’s collected plastic – came to a sudden end at the beginning of 2018, when China refused to accept any more plastic waste.
As China realised, the fundamental problem with recycling is an economic one: about 80% of the plastic has ‘low residual value’.
So what do we do? Three broad strategies seem most promising. First, find a way to clean up the plastic. Second, find alternatives to current plastics that do less harm in the environment. Third, reduce the amount of plastic produced and thrown away by changing how we use it and dispose of it.
CLEANING UP THE OCEANS
Local efforts to clear plastic from beaches, such as the clean-up of the small spill on Shelly Beach, are one thing. What would it take to clean up the oceans? Could we even make a dint in the problem?
A place to start might be the Great Pacific Garbage Patch, an area of open ocean between North America and Asia where the gyre of currents has drawn an estimated 80,000 tonnes of plastic debris into a whirlpool the size of Mongolia. The concentration of plastic in the gyre was first identified in the late 1980s, and has been growing ever since. A recent survey, in early 2018, suggests the patch holds about 1.8 trillion individual pieces of plastic. Most of these pieces are microplastics – pieces smaller than 5 mm – though they only make up 8% of the mass.
In 2013, a Dutch teenager named Boyan Slat dreamt up an industrial scale approach to ocean litter collection. Slat’s idea was to use enormous tubes hundreds of metres long bent into a floating U-shape. Driven by wind and waves, the tubes move with the plastic whirlpool, only slightly faster – which means they will funnel floating debris to a central collection point as they travel. A ship will periodically travel out to collect the accumulated plastic and carry it back to shore for recycling.
Slat’s not-for-profit startup in Rotterdam – called the Ocean Cleanup Foundation – has attracted tens of millions of dollars in donations, including from Silicon Valley heavyweights Marc Benioff and Peter Thiel. The first garbage-collection system is due to be launched in September 2018. If all goes well, more will be added in 2019.
Though the troughs will not catch microplastics – a nurdle would slip from their grasp – they will catch the larger pieces that often break down and produce them. The Ocean Cleanup estimates they will be able to extract half the plastic in the Great Pacific Garbage Patch every five years.
Slat has his eyes on the four lesser garbage whirlpools as well, the gyres in the Indian, Atlantic and South Pacific oceans. “The revenue from recycling and reselling the extracted plastic from the North Pacific gyre will help fund the expansion,” he says optimistically.
The Ocean Cleanup estimates they will be able to extract half the plastic in the Great Pacific Garbage Patch every five years.
Not everyone shares the optimism. The high-profile project has attracted its share of criticisms, from concerns that the troughs will also capture fish to oceanographic arguments that the optimal sites for catching marine microplastics are actually near the coast of China and in the Indonesian archipelago.
These kinds of technical criticisms have helped improve the project, Slat says, but more cutting ones strike at the heart.
“You want to solve a pollution problem at the beginning of the pipe,” says Chris Wilcox, a marine plastics researcher at CSIRO, Australia’s major government scientific organisation. What’s more, the exponentially growing rate of plastic production means any clean-up method will need to scale up just as quickly. “You could clean up the gyres today,” Wilcox points out, “and in 11 years we will have chucked more plastic into the ocean than we have the whole time up to now.”
NEW TRICKS FOR OLD PLASTIC
New technologies to recycle plastics could help to improve the value of plastic waste and boost the economic drivers of recycling. One of the reasons recycling has been the great dashed hope are the limited high-value options. Remelting plastic can degrade the quality, so pristine clear water bottles may be turned into opaque containers or even shredded and compressed into building material. In many cases it’s just as cheap to use new plastic.
Sankar Bhattacharya is a chemical engineer at Monash University in Melbourne with a plan to turn waste plastic into a high-value product: diesel fuel. He has built a small test plant to show that a high-temperature process called pyrolysis can break the polymers in polyethylene and polypropylene apart and recombine their component molecules. “The science is very simple.”
He has put together a business case for a plant that could process 30,000 tonnes of plastic a year and produce 15,000 tonnes of fuel. Depending on fuel prices, he calculates that it would pay for itself in 3–5 years, and he’s currently on the hunt for investors.
Another novel idea can be found underfoot in the suburban street of Rayfield Avenue in Melbourne’s north, and a short stretch of highway in the south of Sydney. In both, the roads have been resurfaced with a more durable form of asphalt called “plastiphalt”.
Devised by recycling company Close The Loop and infrastructure company Downer, plastiphalt uses waste to make asphalt that last 65% longer than the traditional kind.
A kilometre of two-lane road uses the equivalent of 530,000 plastic bags, 168,000 glass bottles and toner from 12,500 spent printer cartridges, according to Close The Loop’s general manager Nerida Mortlock. The first demonstration roads have been surfaced in Melbourne and Sydney, and trials in Brisbane and Adelaide will soon follow. “We want to make this a standard product everywhere,” says Mortlock.
Perhaps the most sophisticated approach now on the drawing board takes advantage of nature’s own response to plastic. In 2016, scientists discovered a bacterium in a Japanese recycling plant that had evolved the ability to devour the common plastic PET (polyethylene terephthalate).
Gregg Beckham of the US National Bioenergy Centre is trying to make the bacteria more efficient at breaking down PET into its component monomers, terephthalic acid and monoethylene glycol. Those molecules could then be used to build the kind of composite materials that can be used in wind turbines or fancy bicycles. “Basically we’re trying to engineer a superbug,” he says.
The holy grail is fully biodegradable plastic: one that will break down naturally in the environment in the same way that plant or animal matter does. This is not to be confused with most existing plastics that simply break down into the microplastics that so worry ecologists and human health experts.
The current frontrunner to replace packaging plastic – which makes up a huge fraction of marine waste – is polylactic acid (PLA). It’s a polymer most often made from corn starch and similar in many ways to PET. A so-called bioplastic, PLA can be recycled to as-new quality and even composted.
Any plastic alternative will face the considerable hurdle of competing against a mature industry that can produce existing plastics so cheaply that the cost of a single bag or bottle is effectively zero.
If pulling waste plastic back out of the environment is a fool’s errand, the economics of recycling is poor and fully biodegradable plastics are still on the drawing board, what scientific solutions are we left with?
The science of human behaviour.
At BehaviourWorks, at Monash University in Melbourne, Kim Borg tests different behavioural modification strategies. The goal is to change norms of behaviour.
For instance, simple actions by businesses such as making customers ask for a straw or plastic bag, rather than supplying one automatically, can have a big effect on behaviour. “It does seem there is a social shift happening. When people are given the opportunity to reduce how much plastic they use, more people are getting on board.”
But are individual consumer choices even the problem? Changing individual habits also seems like an end of the pipe solution: by the time you or I decide whether to use a disposable straw or bring a bag from home to the supermarket, most of the work has already been done.
Environmental economist Ian MacKenzie agrees. A good way to change behaviour all along the line from producers to consumers to waste managers would be to impose a tax on plastic producers, he says. “Environmental economists have been thinking about this kind of thing for a hundred years,” he says. “The policies are there – we just need political leadership on what we’re going to do.”
REVELATIONS FROM SHELLY BEACH
Returning home from Shelly Beach I caught the train three hours back to Melbourne’s Flinders Street station and was greeted by an enormous wave sculpture in a nearby square built from a tonne and a half of discarded plastic bottles.
In an act of “good corporate citizenship”, Corona beer had erected it to raise awareness of the plastic problem.
Not long after, Australia’s two major supermarket chains banned disposable plastic bags from their stores. The Australian Capital Territory began a plastic container deposit and refund scheme, and Queensland will soon follow suit. In America, cities and companies have announced bans on single-use straws and other plastic utensils.
Could it be that the once fringe anti-plastic movement had become an unstoppable juggernaut?
A real solution will need to be international. In late 2017 almost 200 countries signed up to a UN resolution to eliminate plastic pollution in the sea, and there is talk of a formal treaty. Global cooperation to solve environmental problems can work: the 1987 Montreal Protocol which phased out chlorofluorocarbons to protect the ozone layer is the shining example.
On the other hand, the 2015 Paris Agreement on carbon emissions, offers less cause for hope.
The environmentalist’s maxim applies here: think global, act local. Chris Wilcox and his colleagues studied local councils all around the coast of Australia and found that common-sense ideas like prosecuting illegal dumping had a large effect on the amount of coastal waste, as did anti-littering outreach campaigns and making recycling easy.
At the end of the day, he says, it’s a question of value. “We don’t value the material and that’s what leads us to lose it into the environment.”
Plastic has certainly become a compelling material for Colleen Hughson. Her way of seeing the world has changed dramatically since the nurdle spill, she tells me. “I feel like I was going through life half asleep,” she says.
Hughson’s change in global perspective brought with it a drive for local action. “I realised you don’t need to wait for other people to do something.”
Wanting others to wake up, she’s employed artistry. She showed me the plastic debris from beaches around Warrnambool that now fills her back shed, sorted by kind and colour and date and place of collection: red fragments of crayfish pots, blue bottle tops, white bags filled with the haul from one or another day’s cleanup.
Perhaps more importantly, she has made connections with like-minded local residents and businesses, joined a citizen science project called the Australian Marine Debris Database which has logged millions of pieces of beach litter collected around Australia, and even shared knowledge with fellow environmentalists as far away as Scotland who face the same problems on their own shores.
“There have been massive changes in our community since the spill,” she says. “It’s all happened in the last six months. And it feels like it just so happens to coincide with the rest of the world.”