Accumulating ‘microplastic’ threat to shores.


Debris on shoreline (Image: AP)
Concentrations of microplastic were greatest near coastal urban areas, the study showed

Microscopic plastic debris from washing clothes is accumulating in the marine environment and could be entering the food chain, a study has warned.

Researchers traced the “microplastic” back to synthetic clothes, which released up to 1,900 tiny fibres per garment every time they were washed.

Earlier research showed plastic smaller than 1mm were being eaten by animals and getting into the food chain.

The findings appeared in the journal Environmental Science and Technology.

“Research we had done before… showed that when we looked at all the bits of plastic in the environment, about 80% was made up from smaller bits of plastic,” said co-author Mark Browne, an ecologist now based at the University of California, Santa Barbara.

“This really led us to the idea of what sorts of plastic are there and where did they come from.”

Dr Browne, a member of the US-based research network National Center for Ecological Analysis and Synthesis, said the tiny plastic was a concern because evidence showed that it was making its way into the food chain.

“Once the plastics had been eaten, it transferred from [the animals’] stomachs to their circulation system and actually accumulated in their cells,” he told BBC News.

In order to identify how widespread the presence of microplastic was on shorelines, the team took samples from 18 beaches around the globe, including the UK, India and Singapore.

“We found that there was no sample from around the world that did not contain pieces of microplastic.”

Scanning microscope image of nylon fibres
The smallest fibres could end up causing huge problems worldwide

Dr Browne added: “Most of the plastic seemed to be fibrous.

“When we looked at the different types of polymers we were finding, we were finding that polyester, acrylic and polyamides (nylon) were the major ones that we were finding.”

The data also showed that the concentration of microplastic was greatest in areas near large urban centres.

In order to test the idea that sewerage discharges were the source of the plastic discharges, the team worked with a local authority in New South Wales, Australia.

“We found exactly the same proportion of plastics,” Dr Browne revealed, which led the team to conclude that their suspicions had been correct.

As a result, Dr Browne his colleague Professor Richard Thompson from the University of Plymouth, UK carried out a number of experiments to see what fibres were contained in the water discharge from washing machines.

“We were quite surprised. Some polyester garments released more than 1,900 fibres per garment, per wash,” Dr Browne observed.

“It may not sound like an awful lot, but if that is from a single item from a single wash, it shows how things can build up.

“It suggests to us that a large proportion of the fibres we were finding in the environment, in the strongest evidence yet, was derived from the sewerage as a consequence from washing clothes.”

Plastic ‘a threat’ to biodiversity


Microplastics ‘pose toxic threat to marine biodiversity’

Micro plastic
An estimated 150 million tonnes of plastic is “lost” each year

Tiny particles of waste plastic that are ingested by shoreline “eco-engineer” worms may be negatively affecting biodiversity, a study says.

So-called microplastics may be able to transfer toxic pollutants and chemicals into the guts of lugworms, reducing the animals’ functions.

An estimated 150 million tonnes vanishes from the global waste-stream each year.

The findings have been published in the academic journal Current Biology.

“We are losing a large volume of plastic and we know it is going into the environment and the assumption being made by policymakers is that this material is non-hazardous, it has got the same ranking as scraps of food,” explained co-author Mark Browne, an ecologist from the US-based National Center for Ecological Analysis and Synthesis.

“The research we have done really challenges that,” Dr Browne added, referring to the findings of lab work carried out by colleagues at Plymouth University, UK, led by co-author Prof Richard Thompson.

“Our findings show that the plastic itself can be a problem and can affect organisms.

“Also, when particles of plastic go into the environment what you find is that they accumulate large quantities of pollutants that are banned. So you have these particles themselves but also a load of nasty chemicals.”

Important role

The team found that the tiny bits of plastic, which measure 1mm or smaller, transferred pollutants and additive chemicals – such as flame-retardants – into the guts of lugworms (Arenicola marina).

This process results in the chemical reaching the creatures’ tissue, causing a range of biological effects such as thermal stress and the inability to consume as much sediment.

Dr Browne explained that this had consequences for the surrounding ecosystem.

“If the animals are not able to eat as much then there is a change in the function of the organisms and there is an impact on the semblance of the species found in an area,” he said.

He added that the worms had earned the nickname “eco-engineers” as a result of their ability to eat organic matter from the sediment and prevent the build-up of silt.

“Through that process, it produces burrows and changes the whole assemblage of animals that live around it,” Dr Browne observed.

“This is quite considerable because if you look at the total biomass of a shoreline, about 32% can be made up from these organisms.”

He told BBC News that it was the first study of its kind to highlight the toxic risk posed by microplastics to marine organisms.

“For about 40 or 50 years, we have been finding very large concentrations of chemicals in animals. Then they started to find animals with larger concentrations of pollutants and plastics, so researchers began to establish this correlation.

“But no-one had actually shown whether chemicals could transfer from plastic when they are eaten by animals and accumulate in their bodies and reduce important functions that maintain their health.”