What are pyroplastics?

Pyroplastics are derived from the burning of plastic. Some may look like various burnt pieces of plastic amalgamated together, while others look remarkably like pebbles once they have been eroded down by the elements.

They have probably been in existence since we started burning plastic to dispose of it (perhaps 80 years or so). Some of the now restricted chemicals we find in pyroplastics suggest they have been around since at least the 1960s.

Burnt plastic on beaches is likely to be derived from many sources, including burning waste on the beach itself, collapse of old landfill sites, historical burning of waste at sea and contemporary burning of plastic waste on small island states. 

On beaches, many pieces of low density burnt plastic erode down in the swash zone into distinct clasts that look like natural (geogenic) pebbles. 


What are the particular challenges for the public in identifying pyroplastics?

With a geogenic appearance, pyroplastics evade ready detection and would be considered to be normal pebbles to the untrained eye. With pyroplastics and pebbles on a piece of card, students, scientists and members of the public are unable to discriminate between the two types of solid without handling them.

Are there any potentially harmful effects for either humans of wildlife?

Because many pyroplastics are quite brittle they readily fracture into microplastics which are more easily ingested. The consequences of ingestion are unknown but because they contain some chemicals that are now banned, and many organic chemicals formed on combustion are hazardous, it is anticipated that they would display some toxic effects.

<p>Microplastics on the beach</p>
<p>Pyroplastics</p>
<p>Plastic found on the beach<br></p>

Is there anything that can be done to prevent their spread?

Because they are of low density, they are likely to be transported readily in the ocean with other forms of plastic. Because of difficulty in their detection they are more prone to escape removal during beach cleans. While plastic is not burned in open fires on mainland UK, other nations and islands still appear to generate burnt plastic this way.

With growing global awareness of microplastics, how important is it people understand the problem of pyroplastics as well?

Pyroplastics appear to be a different type of plastic litter that has not thus far been recognised. Given difficulties in detection, their propensity to form microplastics and contain potentially toxic chemicals in the matrix it is important that they receive further study and are better understood. Of course, we would recommend that the practice of burning plastic, casually, industrially or institutionally, is ceased completely.

 

Dr Andrew Turner published research in 2019 which spoke about pyroplastics in far greater detail. The study – Marine pollution from pyroplastics – was featured in Science of the Total Environment, doi: 10.1016/j.scitotenv.2019.133610.

International Marine Litter Research Unit

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