New wave of nanoplastics research

Nanoplastics and microplastics are small particles that form when larger pieces of plastic break apart. And this is happening extensively in the ocean, although we don’t yet know what the consequences might be. One outcome is that sticky polymers produced by microorganisms can glue these small plastic particles back together so they form agglomerations that other species mistake for food. Mariana Campos spoke to Tony Gutierrez who’s been studying the effect at Heriot-Watt University in Edinburgh...

Tony - We were interested to understand what happens to nanoplastics in the marine environment. And we observed that like with microplastics they form into agglomerations with biopolymers. These are gloopy, sticky substances that are produced and released by bacteria and microscopic algae or phytoplankton in the ocean.

Mariana - How did you get to the results that you got?

Tony - What we did was we incubated natural seawater with some nanoplastic particles. Within hours we observed the formation of particles and these particles grew in size. And we could see these nanoplastic particles embedded within a web of polymers, and what we wanted to find out after this was what type of polymers could be enveloping these plastics. So we extracted polymers from a particular species of marine bacteria that produces a lot of these polymers, and we incubated them with the plastic particles and indeed we observed the very quick formation of plastics embedded within this web of polymer.

Mariana - Are the agglomerates dangerous?

Tony - We don't know what their impacts could be. One thing we know is that what were invisible nanoplastics have become visible by the formation of these agglomerations. So what this could lead to is these particles which are now visible could be mistaken or seen as a food source and ingesting the plastics that are within them. We don't know what the impacts could be. We do have some data that suggests that there are no toxicological effects, but we still need to do more experimentation to understand that.

Mariana - Have you got other experiments planned for the future?

Tony - Yes so one thing we want to look into that I'm very interested in is, in the formation of these plastic agglomerations, does it have an effect in terms of the degradeability of the plastic particles. So could these agglomerations be a hot zone in the marine environment where the plastics could be broken down or degraded faster by the microorganisms that are associated with these agglomerations. So that's certainly something I'm very interested in doing. What I'm explaining is something that's occurring naturally in the environment. How to enhance that, to get rid of plastics, that's something that really deserves a lot of thinking. I think we still need a lot more information. But one thing at the end of the day really is in order to reduce the concentrations of nanoplastics and microplastics in the environment we just simply need to reduce the entry of plastics into the oceans. So implementation of policies and so forth that really reduce the amount of plastics that go into the environment.