Tag Archives: marine pollution plastics

Forever Dead Products

Yangtze river

In a paper published in 2107 in Science Advances, Roland Geyer of the University of California, Santa Barbara, and his colleagues put the cumulative amount of solid plastic waste produced since the 1950s that has not been burned or recycled at 4.9bn tonnes. It could all have been dumped in a landfill 70 metres deep and 57 square kilometres in area—that is to say, the size of Manhattan

If only it had all remained on land, or even washed up on beaches, where it could be collected. A bigger environmental worry is that much plastic has ended up in the ocean, where, dispersed by currents, the stuff becomes virtually irretrievable, especially once it has fragmented into microplastics. Computer models suggest that seas hold as many as 51trn microplastic particles. Some are the product of larger pieces breaking apart; others, like microbeads added to toothpaste or face scrubs, were designed to be tiny….

Even if the flow of plastic into the sea, totalling perhaps 10m tonnes a year, was instantly stanched, huge quantities would remain. And the flow will not stop. Most of the plastic in the ocean comes not from tidy Europe and America, but from countries in fast-developing East Asia, where waste-collection systems are flawed or non-existent. In October 2017 scientists at the Helmholtz Centre for Environmental Research, in Germany, found that ten rivers—two in Africa and the rest in Asia—discharge 90% of all plastic marine debris. The Yangtze alone carries 1.5m tonnes a year

Trucost, a research arm of Standard & Poor’s, a financial-information provider, has estimated that marine litter costs $13bn a year, mainly through its adverse effect on fisheries, tourism and biodiversity. It puts the overall social and environmental cost of plastic pollution at $139bn a year. Of that half arises from the climate effects of greenhouse-gas emissions linked to producing and transporting plastic. Another third comes from the impact of associated air, water and land pollution on health, crops and the environment, plus the cost of waste disposal.

Exerpts from:  Plastic Pollution: Too Much of a Good Thing, Economist, Mar. 3, 2018, at 51

Production, use, and fate of all plastics ever made (R. Greyer et al., 2017)

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Loving the Plastic Bag

Since their invention in the 1960s, disposable plastic bags have made lives easier for lazy shoppers the world over. But once used, they become a blight. This is particularly true in poor countries without good systems for disposing of them. They are not only unsightly. Filled with rainwater, they are a boon for malaria-carrying mosquitoes. Dumped in the ocean, they kill fish. They may take hundreds of years to degrade. On March 15th Kenya announced that it will become the second country in Africa to ban them. It follows Rwanda, a country with a dictatorial obsession with cleanliness, which outlawed them in 2008…

As Kenyans get richer and move to cities, the amount of plastic they use is growing. By one estimate, Kenya gets through 24m bags a month, or two per person. (Americans, by comparison, use roughly three per person.) Between 2010 and 2014 annual plastic production in Kenya expanded by a third, to 400,000 tonnes. Bags made up a large part of the growth.

Kenya has tried to ban polythene bags twice before, in 2007 and 2011, without much success. This latest measure is broader, but few are ready for it. The Kenyan Association of Manufacturers says it will cost thousands of jobs. Some worry that supermarkets will simply switch to paper bags, which could add to deforestation. And then there is the question of whether Kenyan consumers will accept it. In Rwanda, since its ban was imposed, a thriving underground industry has emerged smuggling the bags from neighbouring Congo.

Excerpts African Rubbish: Plastic Bantastic, Economist, Mar. 25, 2016

Eating Fish in Microplastics

microplastics

One study has estimated that of the 275 million tonnes of plastic waste generated by 192 countries in 2010, 4.8–12.7 million tonnes could have entered the ocean. That’s a serious amount in just one year.

Luckily, some plastic waste is recyclable…However, many of the world’s coastal countries currently do not have such recycling policies nor the technical capabilities, and so large quantities of plastic are not recycled and enter landfill. The durable properties of plastics make them persistent and slow to degrade in the environment, and ultimately non-recycled plastics on land and in the rivers are left to work their way into the oceans.

It’s at this point the story of plastic ocean pollution seems to become synonymous with microplastics. Typically less than 5 mm in size, microplastics can be eroded to particles as small as 1–100 nm – nanoplastics. Using modelling tools it has been estimated a total of 15–51 trillion microplastic particles have accumulated in the ocean. Some start out as large plastic pieces, slowly eroded by water; others start off as microplastics specifically produced for certain uses, eg microbeads in cosmetic products such as facewash, soaps and shower creams. Microbeads … after they have been washed down the drain, they have been found to evade filtration systems at water treatment works and are discharged directly into the oceans…

Another emerging source of marine microplastics from household wastewater is microfibres leaching from clothing when washed. Microfibres are 1/100th the diameter of a human hair and are used for better waterproofing, breathability and flexibility in sportswear. The most common types of microfibers are made from polyesters and polyamides, and according to researchers giving evidence to the UK House of Commons Environmental Audit Committee in 2016, the number of leached microfibres in wastewater could be as many as 1900 fibres per garment.

Although it is relatively easy to develop policies and bans for microbeads and microfibers, these sources are just a drop in the ocean in terms of tonnage….

[P]lastic waste can travel great lengths. As such, waste from one place can become an issue in a region geographically distant from the original source, due to the oceans’ powerful currents…. Microplastics…, can also exist on beaches and in deeper waters of the oceans where animals feed, and it’s here the main large scale threats to wildlife…[T]he main problem is marine wildlife mistaking micro- and nanoplastics for food. Once ingested, they can cause gut blockage, physical injury, changes to oxygen levels in cells in the body, altered feeding behaviour and reduced energy levels, which impacts growth and reproduction….

[T]here is a need to change the way plastic is viewed by society: from ubiquitous, disposable waste to a valuable, recyclable raw material, much like metal and glass. It’s hoped this will increase the economic value of plastic waste.

Better process design is also needed to improve the issue, especially with regards to recyclability and biodegradability. ..[T]he invention of new, bio-based polymers could lead to improved biodegradability, and this would be greatly helped by further research into the degradation of plastics in the environment. The new plastics must retain functionality but degrade to innocuous substances much quicker.

Excerpts from Camilla Alexander-White The massive problem of microplastics,  Royal Society of Chemistry Nov. 15, 2016