Environment Science & Technology

Fish, Chips and Micro-Plastics: Dangers Revealed

Micro-plastics

2016 has seen a crack down on unnecessary plastic use. From the 5p plastic bag deterrent to the public lobbying parliament to ban the use of micro-plastics (or microbeads) in cosmetics.

Microbeads are composed from various plastics, including polyethylene (PE), polymethyl methacrylate (PMMA), nylon, polyethylene terephthalate (PET) and polypropylene (PP). They turn up in toothpaste as a whitening scrub and in exfoliating scrubs for the face and body. Once these are washed down the drain, they are eaten by fish at the bottom of the food chain; this affects all organisms higher up the chain.

micro-plastics

It was over 40 years ago that scientists first reported the presence of small plastic particles on otherwise pristine coastlines and waters (Carpenter et al., 1972). These particles were more recently termed as micro-plastics; defined as plastic particle with a diameter of 5 mm or less (Arthur et al., 2009).

micro-plastics

Micro-beads inside a fish

 

What are micro-plastics?

There are two main types of micro-plastics:

Primary micro-plastics:

These occur in the environment due to the direct release of minute plastic particles into the waterways. The main offenders for this are toiletries (face scrubs, toothpaste), cleaning products (household and industrial) and shot-blasting ship hulls.

Occasionally, primary micro-plastics are discharged into the waterways by the unintentional loss of industrial materials, such as plastic pellets and powders, during transport.

Secondary micro-plastics:

These result from the disintegration of macro-plastic debris such as plastic bags, drinks bottles and cigarette filters. This breakdown is caused by various natural processes  including a combination of wave motion and grinding on shorelines, UV radiation and biological mechanisms such as shredding by marine organisms.

Both types of plastic stem from the same major plastic compounds. The main players are:

Low-density polyethylene (LDPE) – Used to make plastic bags and drinking straws.

High-density polyethylene (HDPE) – Used to make milk jugs and shampoo bottles and even bullet proof vests.

Polyethylene is composed from the repeating (C2H4)monomer:

Screen Shot 2016-06-30 at 21.22.15

Thermoplastic Polyester (PET) – Plastic drinks bottles are constructed from PET – the most recycled plastic in the world. PET has a ‘low glass transition state’ which makes it only suitable for cool substances. When a polymer, such as PET, is cooled below its ‘glass transition state’ it will become hard and brittle – like glass.

micro-plastics

Cellulose Acetate – The major component of cigarette filters. Developed by Swiss Chemists, Camille and Henri Dreyfus in 1904 and initially it was majorly produced for the celluloid industry.

 

Why are these substances harmful?

It is becoming increasingly evident that marine organisms, from plankton to birds, are consuming this plastic. This is harmful to the marine life and other species higher up the food chain: this includes humans.

Researchers have found that 44% of marine bird species ingest plastics and some species even feed plastic granules to their chicks. (Rios and Moore, 2007)

Ingestion of micro plastics doesn’t only occur through direct consumption but also as a result of eating organisms that have themselves consumed micro plastics. ( Fendall and Sewell, 2009). In short, micro plastics are bioavailable to organisms throughout the food web.

Micro-plastic consumption can affect marine organisms in numerous ways including the blockage of feeding appendages, hindering the passage of food through the intestinal tract and causing pseudo-satiation which results in reduced food intake (Tourinho et al., 2010, Derraik, 2002 and Thompson, 2006).

There is another concern to be considered. It is thought that there is a leaching of toxic chemicals from the plastic. Alongside this, pollutants in the sea water are readily absorbed by the plastic fragments which, on a positive note, does clean the surrounding sea water. However, this increases the toxicity of these plastics to the marine organisms ingesting them (Teuten et al., 2009). This leads to toxins being introduced at the very bottom of the food chain and as they say, the only way is up.

 

What happens now?

A 2015 study published by Environmental Science and Technology reported that:

“The United States emits enough microbeads to cover >300 tennis courts daily.”

In December 2015, the US outlawed the selling and distribution of products containing microbeads.

29th June 2016, the Environmental Audit Committee listened to evidence from distinguished researchers from L’Oréal, Unilever and Procter & Gamble. The discussion makes an interesting read . The conclusion being that an outright ban may not be necessary as the industry is taking responsibility for the clean-up of their products by the end of 2017. However, the industry leaders are happy to cooperate with any ban imposed.

Until our toiletries are free from micro-plastics, we can all do our bit by choosing products wisely and avoiding harmful substances.

Fauna and Flora have produced a ‘Good scrub guide‘ to assist choosing micro-plastic free face scrubs:

Here are some examples of other products which have now gone micro-plastic free!

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References:

Greenpeace. 2016. What are microbeads and why should we ban them?. [ONLINE] Available at: http://www.greenpeace.org.uk/blog/oceans/what-are-plastic-microbeads-and-why-should-we-ban-them-20160114. [Accessed 28 June 2016].

The Guardian. 2016. Minister says UK government ‘fully backs’ microbeads ban. [ONLINE] Available at: https://www.theguardian.com/environment/2016/jun/14/nment-backs-microbeads-ban-george-eustice. [Accessed 28 June 2016].

Greenpeace. 2016. Baby fish are hooked on plastic junk food. [ONLINE] Available at: http://www.greenpeace.org.uk/blog/oceans/baby-fish-are-hooked-plastic-junk-food-20160603. [Accessed 30 June 2016].

Parliament.co.uk. 2016. Environmental impact of microplastics inquiry. [ONLINE] Available at: https://www.parliament.uk/business/committees/committees-a-z/commons-select/environmental-audit-committee/inquiries/parliament-2015/environmental-impact-of-microplastics-15-16/. [Accessed 30 June 2016].

Science. 2004. Lost at Sea: Where Is All the Plastic?. [ONLINE] Available at: http://science.sciencemag.org/content/304/5672/838. [Accessed 30 June 2016].

PSLC. 2016. Polyethylene. [ONLINE] Available at: http://www.pslc.ws/macrog/pe.htm. [Accessed 30 June 2016].

Greenpeace. 2016. Microbeads – the story so far….. [ONLINE] Available at: http://www.greenpeace.org.uk/blog/oceans/microbeads-story-so-far. [Accessed 30 June 2016].

 

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