Scientists uncover new ocean threat from plastics





Scientists have identified a new source of chemical pollution released by the huge amounts of plastic rubbish found floating in the oceans of the world. A study has found that as plastics break down in the sea they release potentially toxic substances not found in nature and which could affect the growth and development of marine organisms.



Until now it was thought that plastic rubbish is relatively stable chemically and, apart from being unsightly, its principle threat to living creatures came from its ability to choke or strangle any animals that either got caught in it or ingested it thinking it was food.

But the latest research suggests that plastic is also a source of dissolved substances that can easily become widely dispersed in the marine environment. Many of these chemicals are believed to toxic to humans and animals, the scientists said.

The scale of plastic pollution in the sea has only been widely recognised in recent years when sailing yachts reported vast areas of ocean, such as an area estimated to be twice the size of Texas in the North Pacific, that seem to be permanently covered in a layer of floating marine litter caught up in swirling ocean currents or gyres.

Some of the items were found to be many decades old, suggesting that the plastic took a long time to degrade. However, a study by Katsuhiko Saido at Nihon University in Chiba, Japan, has found that plastics degrade relatively quickly in the conditions and temperatures that were designed to simulate the environment of the open ocean.

“Plastics in daily use are generally assumed to be quite stable. We found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future,” Dr Saido said.

“To date, no studies have been conducted on plastic decomposition at low temperature in the environment owing to the mistaken conception that plastic does not decompose. The present study was conducted to clarify that drift plastic does indeed decompose to give rise to hazardous chemicals in the ocean,” he said.

The scientists found that when plastics decompose in the ocean they release a range of chemicals, such as bisphenol A and substances known as polystyrene-based (PS) oligomers, which are not found naturally. Bisphenol A has been implicated in disrupting the hormonal system of animals.

A common form of plastic rubbish is styrofoam, which soon gets crushed into small pieces in the sea. However, it also releases substantial quantities of a toxic substances called styrene monomer, which is known to cause cancer, as well as styrene dimers and trimer, which are suspected of being carcinogenic. The trimer also breaks down into the toxic monomer form.

Findings from the study were released yesterday at the American Chemical Society meeting in Washington. Dr Saido said that samples of seawater collected from the Pacific Ocean were found to be contaminated with up to 150 parts per million of some of these components of plastic decomposition.

“This study clearly shows new micro-pollution by compounds generated by plastic decomposition to be taking place out of sight in the ocean. Thus, marine debris plastics in the ocean will certainly give rise to new sources of global contamination that will persist long into the future,” he said.

It is estimated that there could be hundreds of millions of tons of plastic rubbish floating in the world’s oceans. In Japan alone, it is calculated that 150,000 tons of plastic is washed up on its shores each year.

News
people'It can last and it's terrifying'
Sport
Danny Welbeck's Manchester United future is in doubt
footballStriker in talks over £17m move from Manchester United
Sport
Louis van Gaal, Radamel Falcao, Arturo Vidal, Mats Hummels and Javier Hernandez
footballFalcao, Hernandez, Welbeck and every deal live as it happens
Sport
footballFeaturing Bart Simpson
PROMOTED VIDEO
News
Kelly Brook
peopleA spokesperson said the support group was 'extremely disappointed'
News
The five geckos were launched into space to find out about the effects of weightlessness on the creatures’ sex lives
i100
Sport
Andy Murray celebrates a shot while playing Jo-Wilfried Tsonga
TennisWin sets up blockbuster US Open quarter-final against Djokovic
Life and Style
techIf those brochure kitchens look a little too perfect to be true, well, that’s probably because they are
Arts and Entertainment
Alex Kapranos of Franz Ferdinand performs live
music Pro-independence show to take place four days before vote
News
ebooksAn unforgettable anthology of contemporary reportage
News
news Video - hailed as 'most original' since Benedict Cumberbatch's
News
i100
Life and Style
The longer David Sedaris had his Fitbit, the further afield his walks took him through the West Sussex countryside
lifeDavid Sedaris: What I learnt from my fitness tracker about the world
Arts and Entertainment
Word master: Self holds up a copy of his novel ‘Umbrella’
boksUnlike 'talented mediocrity' George Orwell, you must approach this writer dictionary in hand
News
i100
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

SQL Implementation Consultant (VB,C#, SQL, Java, Eclipse, integ

£40000 - £50000 per annum + benefits+bonus+package: Harrington Starr: SQL Impl...

SQL Technical Implementation Consultant (Java, BA, Oracle, VBA)

£45000 - £55000 per annum + Benefits + Bonus: Harrington Starr: SQL Technical ...

Head of IT (Windows, Server, VMware, SAN, Fidessa, Equities)

£85000 per annum: Harrington Starr: Head of IT (Windows, Server, VMware, SAN, ...

Lead C# Developer (.Net, nHibernate, MVC, SQL) Surrey

£55000 - £60000 per annum + Benefits + Bonus: Harrington Starr: Lead C# Develo...

Day In a Page

Alexander Fury: The designer names to look for at fashion week this season

The big names to look for this fashion week

This week, designers begin to show their spring 2015 collections in New York
Will Self: 'I like Orwell's writing as much as the next talented mediocrity'

'I like Orwell's writing as much as the next talented mediocrity'

Will Self takes aim at Orwell's rules for writing plain English
Meet Afghanistan's middle-class paint-ballers

Meet Afghanistan's middle-class paint-ballers

Toy guns proving a popular diversion in a country flooded with the real thing
Al Pacino wows Venice

Al Pacino wows Venice

Ham among the brilliance as actor premieres two films at festival
Neil Lawson Baker interview: ‘I’ve gained so much from art. It’s only right to give something back’.

Neil Lawson Baker interview

‘I’ve gained so much from art. It’s only right to give something back’.
The other Mugabe who is lining up for the Zimbabwean presidency

The other Mugabe who is lining up for the Zimbabwean presidency

Wife of President Robert Mugabe appears to have her sights set on succeeding her husband
The model of a gadget launch: Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed

The model for a gadget launch

Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed
Alice Roberts: She's done pretty well, for a boffin without a beard

She's done pretty well, for a boffin without a beard

Alice Roberts talks about her new book on evolution - and why her early TV work drew flak from (mostly male) colleagues
Get well soon, Joan Rivers - an inspiration, whether she likes it or not

Get well soon, Joan Rivers

She is awful. But she's also wonderful, not in spite of but because of the fact she's forever saying appalling things, argues Ellen E Jones
Doctor Who Into the Dalek review: A classic sci-fi adventure with all the spectacle of a blockbuster

A fresh take on an old foe

Doctor Who Into the Dalek more than compensated for last week's nonsensical offering
Fashion walks away from the celebrity runway show

Fashion walks away from the celebrity runway show

As the collections start, fashion editor Alexander Fury finds video and the internet are proving more attractive
Meet the stars of TV's Wolf Hall... and it's not the cast of the Tudor trilogy

Meet the stars of TV's Wolf Hall...

... and it's not the cast of the Tudor trilogy
Weekend at the Asylum: Europe's biggest steampunk convention heads to Lincoln

Europe's biggest steampunk convention

Jake Wallis Simons discovers how Victorian ray guns and the martial art of biscuit dunking are precisely what the 21st century needs
Don't swallow the tripe – a user's guide to weasel words

Don't swallow the tripe – a user's guide to weasel words

Lying is dangerous and unnecessary. A new book explains the strategies needed to avoid it. John Rentoul on the art of 'uncommunication'
Daddy, who was Richard Attenborough? Was the beloved thespian the last of the cross-generation stars?

Daddy, who was Richard Attenborough?

The atomisation of culture means that few of those we regard as stars are universally loved any more, says DJ Taylor