While carbon emissions and the subsequent crisis of climate change are uppermost in most people’s minds regarding environmental threats at the moment, microplastics represent another slow and insidious threat that is advancing on a global scale. So, what is the extent of the problem, and how can it be mitigated?
Managing microplastics – How are we battling yet another unseen threat?
Microplastic ingestion is a daily reality
The global spread of microplastics – tiny pieces of plastic under 5 millimetres in length – is a phenomenon that has uncovered their presence in areas as remote as the Alps, the Artic and even the deepest ocean trench on Earth, the Mariana Trench. This represents a real and present physical threat to all living things on the planet, as microplastics are being ingested by humans, animals, and are even being sucked up by the roots of fruit and vegetable plants at an alarming rate.
Studies around the world are showing that the growing presence of microplastics in our homes, water, food and breathable air is contributing to higher rate of ingestion. New research from a WWF International study suggests that on average, humans will now ingest around 20kg of plastic over the course of their lifetime. Another study from the World Economic Forum found that in Australia, children around the age of five could be ingesting 6.1 milligrams of microplastics (roughly the size of a garden pea) every year just from the air they breathe.
What is the impact of growing microplastic ingestion worldwide?
Currently, there isn’t enough evidence to fully understand the effects of microplastics in the human body. However, researchers already know that microplastic nanoparticles can be toxic when concentrated to a high enough degree, causing carcinogenic and/or mutagenic (damaging DNA) effects. The higher the concentration of microplastics that enter our bodies, the higher the risk of these potentially lethal health conditions emerging – this is the current working theory that is being vigorously tested in labs across the world.
Last month, a study from the University of Portsmouth found that microplastics may even carry harmful bacteria like E. coli up the food chain from seafood to other marine animals and then into humans. A further study from the New Jersey Institute of Technology found that microplastics may also be hubs for other bacteria that are resistant to antibiotics, meaning that the health problems they cause in humans may be harder to treat as a consequence.
Breaking down the problem – what new microplastic management solutions are emerging?
There’s a broadening range of microplastics solutions coming onto the market in response to the growing threat it entails, but this month there are two main approaches that caught our eye. The first involves bacteria of a more targeted, helpful sort.
Microbiology researchers at the Hong Kong Polytechnic University (PolyU) recently released their preliminary findings on their innovation of an engineered bacterial biofilm that can immobilise microplastics floating in water, trap them and make them sink to the bottom of the ‘bacteria trap’. The second part of the innovation is that biofilm-dispersal gene allows the bacteria to dislodge the microplastics in handy ‘blobs’ that make for easy collection and recycling. Given the small size and pervasive nature of microplastics, this approach is exciting due to its scalability and easy deployment process.
At the other end of the scale, we move from a nature-based solution to a wholly artificial one. A new kind of robot, or more specifically, microbot, has been developed by researchers from the University of Chemistry and Technology in Prague, Czech Republic. Remarkably, their solar-powered microbots – measuring only micrometres in width – can actively move towards microplastics, latch onto them and start to break them down through sunlight-driven photocatalysis. While the scalability of the solution remains a question mark at present, it is a proof-of-concept innovation with potentially vast ramifications, since it shows that it is possible to achieve the efficient degradation of ultrasmall plastic particles even in complex environments.
With both solutions, among dozens of other emerging each month, the wider question is how useful they will become in combatting what is now known to be a global problem that reaches into every part of our environment. For now, it seems that as our understanding of the problem itself grows, so does our ability to counter it.