Our love for glitter might be causing serious problems for our oceans! New research has uncovered that those tiny, sparkly bits of plastic – the kind we use for crafts and makeup – can throw off the natural processes that marine animals need to build their shells and skeletons. This is raising alarms about the long-term damage glitter pollution could be causing to delicate ocean ecosystems.   

The study, conducted by scientists at Trinity College Dublin and published in Environmental Sciences Europe, reveals that glitter made from PET plastic actually encourages the formation of minerals in seawater. While that might sound harmless, it can interfere with how creatures like clams and corals create their own protective layers.   

To figure this out, the researchers acted like they were in the ocean and studied six different types of PET glitter. Using some really powerful microscopes and other tools, they saw that the glitter's surface helps calcium carbonate minerals to crystallize very quickly. In fact, this can happen in just minutes or hours! This speedy mineral growth could mess with the way marine animals build their bodies.   

The scientists also found something else worrying: as these minerals form on the glitter, the glitter itself starts to break down. This means it crumbles into even smaller pieces of plastic, adding to the microplastic pollution already in the ocean.   

(a) unreacted glitter microplastic; (b) glitter microplastic almost fully covered by carbonate minerals; (c) detail of a corner of the glitter microplastic covered by calcite minerals; (d) a calcite mineral breaking the layered structure of a glitter microplastic. Photo: Dr Juan Diego Rodriguez-Blanco and Kristina Petra Zubovic.

“Our findings suggest that PET glitter can act like a base for calcium carbonate to grow on, which can have really bad consequences for marine life,” explains Kristina Petra Zubovic, who led the study. “This whole process could weaken the structures of marine organisms that need stable conditions to thrive.”   

Dr Juan Diego Rodriguez-Blanco, the head researcher on the project, also emphasized the seriousness of the situation. “Microplastic pollution is a huge problem worldwide, and our study gives us important new information about how these plastics interact with natural processes in the ocean,” he said. “We need to understand these interactions to figure out the full impact of microplastic pollution on marine life. This research shows we urgently need more studies and better solutions to protect our oceans.”    

Dr Juan Diego Rodriguez-Blanco (principal investigator) and Kristina Petra Zubovic (lead author), in the iCRAG Lab at Trinity

Why is Glitter a Problem?

Glitter is everywhere! We use it to add sparkle to makeup, art projects, clothes, and even holiday decorations. It’s also used in some industrial products like car paint. All this glitter is made up of tiny pieces of plastic, usually PET, which is the same stuff used to make plastic bottles. PET is strong and doesn’t break down easily, which is why it’s becoming such a problem in the environment.   

Glitter isn't just plastic, though. It's made of a PET base covered in thin layers of metals and coloured dyes to make it shiny. This layered structure makes it even tougher and harder to break down. Because the pieces are so small and light, glitter easily washes into our waterways and eventually ends up in the ocean, where it’s nearly impossible to clean up.  

What Did the Researchers Find?

The researchers discovered that when PET glitter gets into seawater, it encourages the formation of calcium carbonate minerals. The glitter's surface, with its rough texture, provides a place for these minerals to latch onto and grow. This can mess with the natural process by which marine animals use calcium carbonate to build their shells and skeletons.   

Even worse, the study revealed that the glitter itself changes during this mineral formation. It can crack and peel, releasing even tinier pieces of plastic into the water. This means glitter not only interferes with mineral formation but also adds to the microplastic pollution problem by breaking down into smaller, more widespread particles.   

All of this raises serious concerns about how microplastic pollution is affecting our oceans and the creatures that live there. By changing natural mineral formation and increasing the amount of plastic bits in the water, glitter could be causing long-term harm to marine ecosystems.   

You can read the full scientific article on the publisher's website.