Microplastics in everyday life

There are a many things that I fear... Antibiotic resistance, plastic pollution, climate change, the rising sea levels, the destruction of our oceans from commercial fisheries, the prevalence of recent shark attacks, the destruction of our soil due to inappropriate farming, coal mining - or mining in general which introduces heavy metals such as arsenic into our soils. This article is not about any of these issues - they warrant a whole article for themselves. Instead, I am going to discuss microplastics. They are a very scary reality.

What is a microplastic?

Microplastics come from the plastic waste that is released into the environment. The plastic waste is exposed to heat, chemical treatment, radiation (such as UV light), microbial organisms such as algae or mechanical stresses, which causes breakdown into tiny microscopic pieces of plastic that can accumulate in the environment and inside living organisms. The sizes typically range from 1 µm to 5 mm and these materials are generally water insoluble.

You have probably heard that single use plastic such as straws, plastic bags, and packaging are the cause of microplastics. It's true that all of our plastic waste eventually breaksdown into microplastics, but clothing, tires and cosmetics can also directly release microplastics into the environment.

The versatility of microplastics

The textile industry (think fashion) is a heavy contributor to environmental destruction through microplastics (35% of all microplastics).

Let us consider a polymer such as polyester. If I were to synthesise it in the lab, it would be a large, potentially yellow solid which is either really sticky or very hard. You would look at it and think that it is just that - a large piece of glob, perfectly harmless. But on the nanoscale, this material is made up of many individual nanoparticles with potential to leach into the waterways, cross our epidermis and accumulate.

To make clothing from polyester, engineers heat up the blob and spin it into a clothing fiber, which is the basis of most of our clothing today. Often polyester is blended with other materials such as elastane and cotton. It has provided society with many benefits, such as moisture wicking properties and durability, not to mention that it is very cheap! But this affordibility is leading to the destruction of the environment.

You see, nature is amazing and finds ways to break down every material - take quartz for example, it fragments into sand overtime. Polyester and other synthetic clothing breaks down into microplastics. You could say "well I will make sure that I dispose of it sensibly.." Surely you wash your clothes though? Washing your clothes overtime leads to the slow decomposition of the polyester fibres - essentially releasing microplastics. It also doesn't help that clothing companies like Shein exist. This "Fast Fashion" is cheap but extremely harmful to the environment as the materials used in the manufacture are not designed to endure.

Furthermore, a single wash cycle is thought to release 700,000 microplastic fibres! These fibres are not only released into our water streams, but are equally released into the air. The release of microplastics into the waterways and air means that noone is safe. We eat animals that have ingested microplastics, which further adds to the problem. In fact, researchers have found microplastics accumulate in vital organs and placenta. In turn, they may cause inflammation leading to respiratory, digestive, dermal and reproductive issues. The seriousness of microplastic pollution is not well understood but we will see the effects in years to come.

Other sources of microplastics

But it's not just textiles that are introducing microplastics. Other sources of microplastics that you probably don't know about include:

• The cosmetic industry: Face scrubs, soaps, shower gels contain plastic microbeads that end up in waste water and breakdown into microplastics.
• Rubber industry: Microplastics are released from the tires on our car! Think about everytime you drive your car, or break. You are releasing 5-10% of all microplastics in the environment.

What are researchers doing right now to overcome this?

First and foremost, microplastic pollution from our clothing can be reduced by designing better quality clothing and incorporating more natural materials.

Alternative materials

Compostable and biodegradable materials are becoming more common. Typical examples include cellulose, polylactic acid, thermoplastic starch (TPS), polyhydroxyalkanoates (PHAs). While cellulose and starch are polysaccharides (think sugars), PLA and PHAs are polyesters.

All polyesters breakdown by the same mechanism: Ester hydrolysis. However, the different esters will breakdown at different rates which is governed by the chemical structure, polymer morphology and crystallinity. Once PLA and PHA are cleaved into individual monomers, these can be solubilised and further broken down by microbial organisms. Thus, the breakdown of these materials also requires the right enzymes to be present to break them down.

Energy recovery technologies

There are research articles that have explored the use of nanofilters, membranes, flotation circuits as well as chemical and biological remediations. With introduction of stricter policies/legislation and funding into innovation, we will see more start ups aiming to solve the issue of microplastics.

Policy

Overtime, many governments around the world have introduced bans on single-use plastic (think plastic straws) and stricter recycling mandates. Companies are required to put labels on waste that can be recycled/composed.

For instance, Sweden developed an advanced recycling campaign designed to turn "trash into treasure" or in other words, convert waste into energy. This is done by burning the waste and capturing the energy generated. In addition:

• the government put the responsibility of disposal onto the producer - i.e. they are legally responsible for collecting and recycling the waste from their products.
• households are required to seperate all items for disposal. So instead of a Red/yellow/green bin scheme,they seperate food waste, packaging, newspaper, electronics, ties, batteries etc.

Future policies should focus on the decrease of plastic packaging and incorporating more natural materials / compostable materials into packaging. While single-use plastics have been ban, I still see supermarkets allowing customers to use plastic bags for their fruit and vegetables. They need to do better - maybe by introducing paper bags only! Or encouraging customers to bring their own fruit bags.

Start ups

There are currently 7 start ups that have created a new product/material/process to combat plastic and microplastic pollution. These include:

1. Ponda with BioPuff: biomaterial based insulation fibres.
2. Circulose:- produced a raw material made from recycled cotton textiles.
3. UNCAGED Innovations:- creates leather alternatives via grains
4. SPINNOVA:- creates cotton-like textiles from wood pulp/waste.
5. Ambercycle:- Creates a high-quality regenerated polyester from waste (Cycora)
6. Samsara Eco:- uses enzymes to breakdown plastics and textiles into the individual components (monomers), which can be reused to create new "virgin" materials. They focus mostly on Nylon 66.
7. FEVVERS: Creates a plant based alternative for feathers.

As policy shifts, we will see more startups with ideas to help with plastic pollution. Until then, there are some things that you can do to cut down on plastic waste and thus microplastic release.

What can I do at home?

The first course of action that one could take to improve their impact on the planet is to stop buying from brands like Shein. We could all do better by trying to buy clothing that is made up of natural fibres - think cotton, wool, bamboo. Of course this compromises the rigidity of clothes used for sports. When synthetic fibres are unavoidable, a cold and quick wash with a low spin should be used to prevent the breakdown of the fibres. The dryer should always be avoided for synthetics and hang in the shade to prevent breakdown by UV. Better yet, wash your clothes only when they are truly dirty.

Second, we could buy responsibly. Instead of filling a plastic bag with fruit at the supermarket, invest in a fruit bag. Better yet, don't fill a plastic bag, but wash the fruit when you get home. I've seen many people take a plastic bag to fill with bananas. Why?!?!

We should avoid buying foods that are wrapped in excess food packaging when possible; actually, avoid any additional waste where possible and read the labels on the clothing we buy, to cut down on potential microplastic release.

References

1. Frias, J. P. G. L.; Nash, R. Microplastics: Finding a consensus on the definition. Marine Pollution Bulletin 2019, 138, 145-147. DOI: https://doi.org/10.1016/j.marpolbul.2018.11.022.
2. Liu, J.; Liang, J.; Ding, J.; Zhang, G.; Zeng, X.; Yang, Q.; Zhu, B.; Gao, W. Microfiber pollution: an ongoing major environmental issue related to the sustainable development of textile and clothing industry. Environment, Development and Sustainability 2021, 23 (8), 11240-11256. DOI: https://doi.org/10.1007/s10668-020-01173-3.
3. Liu, J.; Liang, J.; Ding, J.; Zhang, G.; Zeng, X.; Yang, Q.; Zhu, B.; Gao, W. Microfiber pollution: an ongoing major environmental issue related to the sustainable development of textile and clothing industry. Environment, Development and Sustainability 2021, 23 (8), 11240-11256. DOI: https://doi.org/10.1007/s10668-020-01173-3.
4. De Falco, F.; Di Pace, E.; Cocca, M.; Avella, M. The contribution of washing processes of synthetic clothes to microplastic pollution. Scientific Reports 2019, 9 (1), 6633. DOI: https://doi.org/10.1038/s41598-019-43023-x.
5. De Falco, F.; Cocca, M.; Avella, M.; Thompson, R. C. Microfiber Release to Water, Via Laundering, and to Air, via Everyday Use: A Comparison between Polyester Clothing with Differing Textile Parameters. Environmental Science & Technology 2020, 54 (6), 3288-3296. DOI: https://doi.org/10.1021/acs.est.9b06892.