What's the deal with microplastics?

by James Atkinson

When our waste is visible and clearly mismanaged, we take action but what can we do when we can't see the problem?

It’s easy to develop a sense of responsibility towards the things that we can see, the things that are obvious, the things that are in our face.  Less-so for the things we can’t see, the wicked problems that are hidden from view.  When our waste is visible and clearly mismanaged, we take action – it might be that we pick up bits and pieces ourselves or through organized clean up events (like these) , it may be a phone call to the council ranger, or it might be canvasing our local MP.

We tend to tackle these problems head-on, and as a society, we are quite relentless in seeking out remedies and solutions.

We know that waste is a major problem across the world, and a large part of this problem is plastic waste. It is widely understood that plastic takes a very long time to break down into its mineral components, but until recently, not much thought was given to the journey to get there and what implications that might have for the natural environment. We are learning that size is an important factor in understanding the risks posed by plastics and what might be done to counteract those risks.

To consider different sizes of plastic , researchers generally use the following categories and ranges:
Nanoplastic = <1μm                      Microplastic= 1μm - ≤5mm                        Macroplastic= >5mm

Noting that 1 micron (micrometre, µm) = 0.001 millimeters (mm) = 0.0001 centimeters (cm). 

Each category presents different risks. We know a lot about macroplastics, these are the bits we can see, the stuff that’s in our face.  We may not be winning the war just yet, but we know a lot about what we are dealing with, and we are at least on our way to tackling the problem. For the smaller plastics though, there is a lot we need to learn. We are starting to see the picture emerge, and the picture is pretty grim.

When plastics are deliberately manufactured to be microplastics (for example microbeads used in exfoliants and toothpastes), these are known as primary microplastics. Secondary microplastics are those pieces that come from the breaking down of larger pieces, and these could be any manner of things – shopping bags, clothes, furniture, consumer electronics – you name it, if it’s plastic it will ‘shed’ microplastics throughout its long life. This is a fundamental problem for almost all types of plastic, the sheer longevity of these items makes their management particularly difficult when they become waste.

Because of their size, and the ease at which they can transported around the natural environment (by wind, stormwater and water run-off, tides etc.), microplastics have been found almost everywhere. From the deepest trenches in the ocean to the top of Mount Everest, they are in our soils and sediments, they are in fresh and salt water, and they are even in the air. Also because of their size, microplastics are attractive as potential food sources for a wide range of organisms, particularly at the lower levels of the food chain. This uptake by small and even large creatures on land and water might happen through confusion with natural prey, accidental ingestion or transfer in the food chain (the scientific journal Nature has an excellent article that discusses this uptake and transfer in fish). The myriad colours that appear in microplastics may also make them appear as a source of food.

The impacts that ingested microplastics have in the food chain has been shown to include false satiation (i.e., feeling full without any actual nutrition), lower rates of reproduction and reduced numbers of offspring organism produced), lower growth rates and heightened immune responses. It is thought that these negative impacts are the result of the physical and chemical properties of the plastics and also due to toxic chemicals that those plastics absorb when they pass through a range of built and natural environments.

We are only starting to understand what the implications might be for humans. As microplastics breakdown into nanoplastics, it is thought that they can pass into the cell membrane. Biologist Dr Pryiom Bose, reporting on recent studies of nanoplastics on fish in AZO Greentech tells us that negative impacts have been shown in metabolism, neurological behaviour, intestinal microbiome diversity, and intestinal permeability. As a reasonably new field of study, we can expect to understand more in the near future, it doubtful the news will get better.

We can never know with absolute certainty exactly how much plastic waste is being produced every year. Researchers estimate that it is in the order of around 380 million tonnes per annum, and since the invention of Bakelite in 1907, humans are thought to have created 8.3 billion tonnes of plastics in total (give or take) – it is thought that about 6.3 billion tonnes now appear as waste. The size of the problem is truly massive. Although the outlook is somewhat bleak, the fact that problems are being identified gives us some cause to remain positive. 

WHAT CAN WE DO?

Even small steps to reduce the flow of plastics into the environment will be beneficial, and as we take these steps, we will likely come to understand what more can be done and how we might scale up solutions. It will take all levels of society to commit to courses of action – government, industry, community and individuals will all need to tackle the problem if we are to reverse the damage being done.

In the first instance we can do our best as households to eliminate the direct use of primary microplastics. Most of us find these in cosmetics / personal care products, but it’s not always obvious if they contain microplastics. UK site beatthemicrobead provide some excellent guidance with over 500 personal care products listed and rated according to the microplastics they contain.

If you can’t find the information you need there, using search engines online can be very helpful, or directly communicating with producers with a request for information will usually yield results (be patient, they are not always quick to respond).

It’s unlikely we’ll ever be able to eliminate all secondary microplastics. Plastics are used in critical medical equipment, building materials, clothing, vehicles, computers and countless other things that have become essential across all walks of life. We can have an incredibly positive impact through choosing wisely what we consume and how much we consume. Single-use plastics should be avoided – bring your reusable shopping bags to stores whenever you can, use refillable cups for take-away drinks, refillable produce containers at the grocers and spend a little time organising that sustainable picnic. We can also use microplastic filters in our laundry and use a gentler approach to washing clothes. 

Look for alternatives and do your own research… “biodegradable plastics” are not always what they claim to be, so use caution. Seek out natural fibres and sustainable timber products particularly in clothing, furniture and building products. There are plenty of alternatives, particularly in these realms, and you probably wont be surprised that these products are often of high quality and excellent durability (without the prospect of being a close-to never ending problem).

What these approaches are telling us is that there are new methods for tackling microplastics emerging all the time, so we need to keep our eyes and ears (and our minds) open. Stay informed and be active, share your thoughts with others and remain optimistic. If the past few years has taught us anything, its that we work better together.

Jim is a dad, writer, PhD researcher and corporate sustainability advisor.