The Plastic Pollution Global Challenge
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The plastic GGllpooobblaalll uCCthhiaaolllnlee nnggee Plastic pollution is a problem that has truly ‘gone global’. entire 20th Century (the start of Fragments of plastics have been carried by planetary-scale which marked the ‘birth’ of plastic). The problem has also been ocean currents to the remotest corners of the world, exacerbated by the global trade in including both Arctic and Antarctic wilderness areas. The cheap commodities driven by low tendency of large fragments to shatter into smaller pieces wages in parts of the world such as creates health hazards for sea birds and other marine China – as well as an insatiable organisms that swallow plastic or get tangled up in it. Action appetite amongst consumers in developed and emerging economies is needed at a range of scales to address the degradation of for ‘cheap and cheerful’ goods such Earth’s oceans and shorelines by plastic debris. as toys, as well as for elaborately- wrapped products and bottles of water. In the USA, 2 million plastic lastic is an essential material usefulness of less than one year). bottles are used every 5 minutes. P for society. It even helps us The economics of plastic production Of the 13 billion plastic liquid meet many of the other big 21st support this unsustainable approach containers that were used in the UK Century challenges that we face, for to resource use: plastic is alone last year, just three billion instance by providing materials that inexpensive, durable, and so is were recycled. What became of the aid efforts to boost food and water frequently designed without any remaining ten billion empty production, such as polytunnels or intention to reuse it, as the material bottles? Many will have been irrigation pipes. Plastics are now part has low manufacturing costs destined for landfill. A significant of everyday life. Toothbrushes attached (unlike some metals). number of others undoubtedly found (above), credit cards, mobiles, During the last 60 years, the their way to the Pacific Ocean, asthmas inhalers, Lego bricks, biros: amount of plastic waste has risen carried by run-off and sewer all come from plastic. from 5m tonnes / year in the 1950s discharge from urban areas. However, a third of all the plastic to 260m tonnes / year in 2010. Our oceans are now full of plastic we use is purposely designed as More plastic was produced globally waste, some fragments of which can ‘throwaway’ (with an expected in the ‘noughties’ than during the be dated as far back as the 1940s. 1 Ocean circulation patch’ which is twice the size of in the early stages of physical Texas. Floating plastic objects breakdown caused by attrtition. The operation of planetary-scale become trapped for several years in Newer fragments have sharp edges, surface currents and the ocean the enormous ‘slow whirlpool’. The older fragments are more rounded. conveyor results in marine pollution ‘plastic soup’ is made up of shampoo They may still be brightly coloured quickly being spread to areas far caps, soap bottles and fragments of which causes some birds and fish to away from the original source. Some plastic bags. In 1999, researchers mistake the fragments for their usual of the remotest shorelines on the counted one million pieces of food sources such as shrimps. planet are now spoiled by pollution floating plastic per square mile in Small pellets of plastic that have that has been carried half-way this area of water. This plastic been eroding for a longer period of around the world (Photograph 1). pollution assumes a number of time. On beaches, these particles Large areas of Earth’s oceans are different forms: may be the same size as grains of heavily polluted with plastic Large recognisable objects such sand and not easily detected at first. fragments due to the operation of as bottles, bottle caps, bags, broken Small manufactured pellets also surface gyres – circular currents in dolls, used biros. If ingested these enter the ocean directly – these are the oceans, moving clockwise in the can be extremely harmful to fish, called ‘nurdles’ (Photograph 2). northern hemisphere and anti- birds or marine mammals. Other Microplastic pellets are the clockwise in the southern risks attached to these objects smallest detectable physical hemisphere (Figure 1). include the strangulation or fragments resulting from further In the north Pacific ocean, there suffocation of birds or animals. physical breakdown of plastic waste. is now a floating plastic ‘garbage Large pellets or shards of plastic Research has shown that waters around the north-east Atlantic are contaminated by such microscopic fragments of plastic. The abundance of this material has increased significantly over the last 40 years. Smaller than the diameter of a human hair, these tiny debris particles have been formed by the breakdown of everyday items such as plastic bags, bottles and plastic materials used in packaging. Chemicals are produced by the decomposition of some plastics in warm waters (around 30ºC). Although this chemical weathering is confined to warm tropical waters, ocean currents circulate the resulting chemicals around the planet. Sources and sinks Photograph 1 A polluted beach in Montevideo Where has this refuse come from? The answer is that it has been flushed into oceans by run-off and sewer discharge from thousands of different cities all over the world. With so many origins, it becomes a very difficult pollution problem to tackle at source. Plastic is now believed to constitute 90 per cent of all rubbish floating in the oceans and the UN Environment Programme estimates that every square mile of ocean contains 46,000 pieces of floating plastic. It would be a mistake to imagine that the rest of the world’s oceans are relatively free of litter thanks to the operation of the gyres. Some studies have found microscopic plastic ‘dust’ to be more numerous than phytoplankton in many parts of Figure 1 Surface gyre currents (Source: Wiki Commons) the world’s waters. Plastic dust is 2 Key terms Scotland will have some plastic debris in their gut. Worldwide, 260 Attrition A physical process that species bird and mammal are known involves particles that are being to ingest or become entangled in carried by the wind, water or ice plastic wastes (Photograph 3). being broken apart into smaller and Discarded red lids from water more rounded fragments. Some bottles are a particular problem – in plastics are also broken apart by the size and colour they mimic the process of photo-degradation caused appearance of the krill shrimp that by light absorption. albatross eat. Autopsies have shown an abundance of red-coloured debris Gyre A slowly moving spiral of in the gut of dead albatross birds. oceanic currents created by a high- Photograph 2 ‘Nurdles’ on a beach Plastics sometimes undergo pressure system of air currents. A chemical decomposition at a gyre can form a place for ocean molecular level in warm tropical debris to accumulate. The North of the most remote places on planet, waters. This can result in the release Pacific Garbage Patch is estimated to yet plastics from Norway, Spain and of a chemical called bisphenol A be bigger than the size of the State of the USA litter its beaches. This is a (BPA). Japanese researchers have Texas. pollution problem does not respect found that some samples of sea boundaries. water contain up to 50 ppm of BPA. Marine ecosystem The term Plastic pollution of the Hawaiian This can become a problem because ecosystem describes a grouping of islands, such as Tern Island, has BPA functions as an endocrine plants and animals that is linked been widely filmed and studied - and disruptor (especially for organisms with its local physical environment provided an important stimulus for higher up the marine food chain) – (for instance through use of soil the recent consumer -led drive to which impairs reproduction. nutrients). The oceans, covering two- reduce plastic bag dependency All direct impacts on one marine thirds of our planet, are home to amongst UK shoppers . species will indirectly impact on distinctive ecosystems composed of other species due to the way that fish, aquatic plants and sea birds – Marine ecosystems marine food webs function. as well as tiny but very important organisms such as krill and Pollution can have damaging effects plankton. What solutions exist? on marine ecosystems and may reduce biodiversity. In recent years, Ocean conveyor A global ocean The size and scale of this problem scientists have become increasingly circulation between deep, colder makes it an enormous global concerned with the impacts of plastic water and warmer, surface water challenge. Action needs to be co- pollution on marine species and food that strongly influences regional ordinated amongst the world’s webs. Data on sea birds showing the climates around the world. producers of plastics as well as ingestion of plastic waste as being a consumers in every country on the cause of death first began to appear planet. There is also an important in the 1950s. 95% of dead fulmars (a role for government at varying scales common sea bird) washed ashore in ubiquitous in UK coastal waters Photograph 2 Soldiers help rescue in helping to regulate consumer and injured citizens in Port-au-prince coastal waters, for instance. The entirety of the world’s oceans has been affected by this problem. The ocean conveyer – a 'water motorway' that runs through the entire world water system – continues to distribute and redistribute plastic waste all around the planet. In addition to the garbage patches, some high-profile discoveries of plastic pollution have been made in important wilderness regions: Dr Simon Boxall, lecturer in Oceanography at the University of Southampton, made the worrying find of a high level of plastic rubbish on a remote Arctic island over 1,000km from the nearest town or village, carried there from polluting countries all around the world by ocean currents.