What Lego bricks tell us about how long plastic dispersed in the sea lasts

An English study has estimated how long it takes for Legos to completely degrade at sea. The results help to understand the effects of plastic pollution in the oceans

(photo:

Xavi Cabrera / Unsplash) ambient Every year we produce 300 million tons of plastic, of which about eight million are destined to end up in the seas and oceans. Straws, bags, and artifacts of all kinds, for a total of about 150 million tons of garbage currently dispersed in the marine environments of the planet. An authentic ocean of plastic, which we will have to find a way to remove to mitigate the risks it poses to the survival of many marine animals, given that left to themselves these materials take centuries, if not millennia, to degrade (and this without counting the risks which they continue to place once transformed into microplastic).

An English study helps to get a precise idea of ​​the time horizon we are talking about: the research, published in the journal Environmental Pollution, has in fact evaluated how long the most resistant plastic artifacts to completely degrade due to the action of waves, sun, sand and contact with salt water. And he did it using one of the most iconic plastic products invented in the 1900s: Lego bricks.

Why Legos

The choice of Legos is not accidental, and it is not linked solely to their fame. As the authors of the study explain, Danish bricks are, in spite of themselves, among the most popular plastic finds collected by volunteers on beaches around the planet. More than 60 billion specimens are produced every year and with similar numbers it is inevitable that accidents, neglect and rudeness will cause enormous quantities of them to end up in the seas and oceans.

Even the small owners of these toys unintentionally contribute to making things worse: younger children have a tendency to dump any small object they find their hands on in the toilet and Lego bricks are among the favorite victims. It is estimated that in the United Kingdom alone in the last few years, about 2.5 million Lego bricks have made this end, which once ended up in the sewer system all too often manage to make their way to rivers, and therefore seas and oceans.

The plastic used by Lego is also particularly resistant, and although it is recyclable with the necessary precautions, it is not produced to be biodegradable, and is therefore destined to accumulate in the environment if it is not disposed of correctly. In short, it is the perfect test bench to verify how long our plastic waste remains in the marine environment.

The study method

The researchers first collected Lego specimens recovered in recent decades on the beaches British and with a meticulous work of investigation have therefore dated and compared them with identical bricks kept by the many collectors present in the United Kingdom. By weighing the pairs of bricks (those collected from the sea and those in good condition kept by enthusiasts) they were therefore able to establish how quickly they are eroded by the action of atmospheric agents, salt water and sand.

The bricks examined they had lost between 3% and 40% of their mass by remaining in the environment for decades. This allows us to estimate that a Lego brick can take from 100 to 1,300 years to completely degrade in the marine environment, a large fork that probably depends on the amount of physical stress to which they are subjected: 1,300 years would therefore be the time required to see a brick deposited on the bottom of the sea, sheltered from waves and atmospheric agents, and 100 years the one it takes to degrade a brick dragged to the shore and subjected to the action of wind, waves and sand abrasion.


Environment - 18 hours ago

July 2021 was the hottest month ever


The Taliban's takeover in Afghanistan will also have environmental consequences


How much do we really know about the nutritional composition of vegetable meat?

Topics

Environment Lego Plastic globalData.fldTopic = "Environment, Lego, Plastic"

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.