For several weeks now, it has been known about the existence of a microplastic spill, specifically plastic pellets, which is mainly reaching the Galician coasts and threatening the Asturian beaches. The magnitude of this spill is such that it is now called the “white tide,” in reference to the Prestige oil spill that reached the same coasts 21 years ago.
It has been a month since the spill and hardly any scientific data is known about it. There is no official report and a lot of information is being published in different media and social networks that, sometimes, is incomplete or directly incorrect. This article tries to contribute data and science to this environmental disaster by detailing or clarifying the information given these days.
A container ship lost part of its cargo when six containers fell into the sea. At least one of them was loaded with plastic pellets (commonly known by the Anglo-Saxon term pellets or nurdles, and in Spanish they are also called plastic pellets), small plastic balls of about 4-5 mm in diameter that are used to manufacture various plastic products, such as bags or containers.
The specific ship was the Toconao, registered with the IMO number 9627899, which currently sails under the Liberian flag.
According to the information given by the authorities to the media, the ship lost its cargo on December 8 and the first sighting of these pellets on land was on December 13 on the beaches of Corrubedo, in the municipality of Ribeira (A Coruña, Galicia). ).
Although the loss of containers was in Portuguese waters, to date there is no indication of the arrival of the pellets to Portugal.
At the moment, the current is dragging them mainly towards the north, since in winter the predominant current is in that direction. In summer it will be towards the south, so there could be another rebound in arrivals to the coast by then.
At the moment the composition of these pellets is not known. It is known that they were manufactured by the company Bedeko Europe and the bags were identified as material with UV light stabilizers. It is normal to add additives to pellets so that they have certain specific properties, and in this case they are more resistant to UV light (something quite common). It is possible to find out its composition with an FTIR (Fourier transform infrared) spectrophotometer in a few minutes.
About 400.3 million tons of plastics are manufactured worldwide, of which 45.2% are composed of polyethylene (PE) or polypropylene (PP). The fact that these pellets float (have floated to shore) indicates that they have a lower density than seawater and are therefore not likely to be made of PVC (polyvinyl chloride) or PET (polyethylene terephthalate). ). The probability that they are PE or PP is quite high.
Each bag found weighs 25 kilos – according to the Noia Limpa association – and, based on our studies, we know that each pellet weighs around 20 milligrams. This implies that each bag contains 1.25 million microplastics.
An average pellet container weighs around 20 tons. Based on these data, the container would contain between 800 and 1,000 bags, if it were fully loaded with these particles (which is usual) and not sharing the load with other products.
In that case, assuming that only one container holds pellets (and not all six), it would transport more than 1 billion pellets.
On January 5, the Sea Councilor of the Xunta de Galicia, Alfonso Villares, reported that the microplastics lost off the Portuguese coast were already reaching those of Asturias and Cantabria. However, on the date he made said statement, the northernmost point that the spill had reached was the Finisterre area.
Several days later they began to arrive in the regions near the cities of A Coruña and Ferrol. The arrival in Ribadesella, Asturias, was reported on January 8.
It must be taken into account that this is not the only accident of this nature. They have been happening in the open sea for decades. Every day large quantities of pellets arrive at different coastal points in Spain and other parts of the world from other spills. We will most likely observe pellets on any Spanish beach we analyze.
No microplastic (or plastic) is an inert material. It is true that they do not react with water, nor do they stick to the substrate like oil would, but they are made of chemical compounds, which have in their composition additives such as phthalates or bisphenol A, which are toxic and harmful if ingested, since they can be transferred to the animal that consumes it. It is a mistake to call them “inert” because it implies considering them non-toxic and this is not correct.
The “white tide” is a spill with many characteristics similar to a hydrocarbon spill. It is essential to act at sea, with containment barriers that minimize dispersion, avoiding as much as possible that they reach the coast, where it will be much more difficult to carry out the cleaning work.
It is also necessary to know the transport and dispersion models to know where to focus efforts, because like so many other equivalent accidents in the past, most of these pellets will be transported by currents for a long time before ending up on a beach. .
Daura Vega Moreno is a Contract Professor of Analytical Chemistry at the University of Las Palmas de Gran Canaria.
This article was originally published on The Conversation
