Microplastics, a threat hiding in plain sight!
They are pervasive and appear in almost every corner of the globe. Primary and secondary microplastics have been discovered in oceans, lakes, water bodies, soil, the atmosphere – and even within our food supply and drinking water!
Read about their impact and how can we reduce the amount of microplastics in the environment.
Microplastics — minuscule plastic fragments certainly pack a punch. They are simply plastics with a diameter of less than five millimetres, making them even smaller than a frozen pea.
Where do they come from?
The origins of microplastics span diverse sources such as landfills, everyday households, personal belongings, construction sites, industrial facilities, agricultural practices, and more. Since the 1950s, we have unleashed a staggering 8 billion tons of plastic, with an estimated only 10% being recycled.
Within the domain of microplastics, there exist two distinct categories: primary and secondary. Primary microplastics are engineered plastic particles designed for specific functions. These tiny plastic spheres can be found in exfoliating facial cleansers or exist as a fine, powdery component in toothpaste and sunscreen, just to name a few. Alarmingly, they often elude wastewater treatment facilities, infiltrating our vital waterways.
On the other hand, secondary microplastics are large plastic materials that can be used in packaging or building materials that just get ground down over time either through abrasion, wind, or sun rays to become microplastics. Common culprits include plastic bags, bottles, and food containers, as well as a broad range of paints, adhesives, coatings, and electronic equipment. Another unsuspected source of microplastics is the washing of synthetic fibre clothing, an everyday activity that inadvertently contributes to the growing microplastic crisis. New technology is being developed to help mitigate this, like a small device designed to go in your washing machine that traps microfibres.
Where can we detect the presence of microplastics?
Research suggests there's scarcely a part of the world untouched by microplastics. However, our understanding of microplastics in the air and soil lags behind our grasp of microplastics in water. This is because detecting, testing, and analysing microplastics in water is comparatively straightforward, thus drawing the primary focus of researchers to date.
However, it came as no great surprise when, in 2022, researchers from the Netherlands and the UK reported the discovery of minute plastic particles in living human beings, in places previously unthought of – deep within the lungs of surgical patients and in the bloodstream of anonymous donors. While neither of these two studies answered the question of potential harm, they collectively marked a shift in the focal point of concern towards the airborne microplastic particles we potentially breathe in every day – some so small that they can infiltrate deep within the body, even penetrating cells, in a manner that larger microplastics cannot.
Sewage also emerges as a significant contributor to the dispersion of microplastics. This becomes especially concerning, as sewage sludge is frequently employed as a form of fertiliser in agricultural fields, resulting in the deposition of several thousand tons of microplastics into our soil annually. In addition, plants cultivated on land contaminated with microplastics have also been found to absorb microplastics, which may enter the food chain following harvest and be ingested into the human body.
Microplastics have also infiltrated salt, beer, fresh fruits and vegetables, commercial food, and even drinking water. Airborne particles can circumnavigate the globe in a matter of days, descending from the atmosphere like gentle rain.
What are some of the enviro impacts?
Plastics are made from a complex combination of chemicals, including additives that give them strength and flexibility. Both plastics and chemical additives can be toxic. Additives can also leach into water, depending on factors that include sunlight and length of time immersed.
Microplastics have profound environmental impacts, with most of the research so far focusing on their effects on marine ecosystems. Once liberated or fragmented from their original plastic source, microplastics embark on a journey through waterways, eventually infiltrating habitats that are home to diverse marine organisms, including algae, zooplankton, fish, crabs, sea turtles, and even birds.
In marine environments, they pose a significant concern because they are easily ingested by living organisms. When fish or invertebrates ingest these microplastics during their meals, they can suffer from health issues, including severe interference or abrasions within their digestive tracts, often proving fatal.
Moreover, these microplastics serve as magnets for other pollutants in the water, so when animals consume them, they also ingest these toxic chemicals. These substances then build up in their bodies and accumulate up the food chain, posing a threat to the broader ecosystem.
Things aren’t looking much better when it comes to the terrestrial realm. Researchers in Germany are warning that the impact of microplastics in soils, sediments, and freshwater could have a long-term negative effect on these ecosystems. They have reported that terrestrial microplastic pollution is much higher than marine microplastic pollution – an estimated four to 23 times higher, depending on the environment.
Overall, the issue with microplastics, similar to most plastics, lies in how long they take to degrade. Plastics can endure for hundreds or even thousands of years, inflicting ongoing damage on the environment. On shorelines, microplastics manifest as minuscule, multicoloured plastic fragments embedded in the sand. In vast oceans, microplastic pollution frequently becomes a meal for marine creatures.
What are the potential implications on human health?
The potential human health implications of microplastic exposure remain a topic of concern. Research has confirmed that microplastics can enter human tissues in three ways – ingestion, inhalation, and skin contact. It's important to note that inhaling very fine particles, regardless of their material, can trigger respiratory irritation that may lead to more severe cardiovascular issues. Nonetheless, many questions persist regarding the impact of microplastics on human health and how our bodies respond to the amount that we consume through the three exposure routes. Many studies have been and are being conducted to find more specific answers.
However, there is a known correlation between microplastics, pollutants, and toxicity.
Numerous factors can influence the toxicity of microplastics, including their size, shape, surface charge, weathering/aging processes, and adsorption capabilities. Larger particles are less likely to penetrate our cells and induce lower oxidative stress, which can lead to inflammation. In comparison to spherical microplastics, irregularly shaped fragments can cause more severe physical harm.
Research has shown that microplastics can affect various systems in the human body, including the digestive, respiratory, endocrine, reproductive, and immune systems, and that the toxicity associated with microplastics varies with factors such as cell type, particle size, dose, charge, exposure duration, type, and additives.
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Science insight Polymers serve as the building blocks for numerous natural structures, from trees to human skin and even the foods we consume. In addition to polymers, microplastics often contain additives, and environmental changes can trigger the release of these additives, resulting in toxicity. Additionally, due to their small size and surface energy, microplastics can serve as vectors for adsorbing other pollutants, particularly heavy metals, and hydrophobic organic chemicals, which can exacerbate toxicity. |
However, the long-term, concealed health consequences are still largely unknown territory.
Our bodies have evolved to break down and process natural polymers over millennia, but novel, synthetic polymers present a host of unknowns. We remain uncertain about the extent to which these human-made polymers differ in their effect on our bodies. While our bodies are well equipped to handle natural polymers, we have not yet had the opportunity to adapt to process these artificial polymers in the same way.
The plan for the future
All governments around the world are taking steps to reduce plastic pollution to reduce the amount of microplastics being released into the environment.
The Queensland Government has developed a plan called Tackling Plastic Waste—the Plastic Pollution Reduction Plan to set the course of the state to be part of the solution.
The plan aims to leverage a holistic approach and provide essential leadership for achieving long-term transformation by pinpointing actionable measures throughout the entire plastic supply chain.
This approach will fund itself on environmental responsibility while unlocking fresh economic prospects and employment avenues for Queensland. These opportunities materialise through investments in plastic processing, remanufacturing, and the exploration of new products and markets as alternatives to conventional plastic.
The idea is also to collaborate with industries to eliminate unnecessary and problematic plastic usage while seeking viable replacements for single-use plastic items. Furthermore, it will spearhead the identification and development of new enterprises and markets that revolutionise the recovery, reuse, and recycling of plastic.
On the other hand, it is important for consumers to stay informed about what they can do in their everyday lives to contribute. Taking steps such as avoiding single-use plastics by embracing reusable glass bottles and containers, and steering clear of products containing microbeads, such as exfoliating cosmetics, is a good start.
There are new, innovative, environmentally friendly plastics also making their debut, which are worth looking out for. Many of these novel plant-based, biodegradable products bear a striking resemblance to the natural polymers found in trees, leaves, and grass.
The Queensland Government also has some useful resources for individuals and businesses to reduce the consumption of avoidable and single-use plastics.
Other useful resources for readers:
What is the government doing about this problem?
State:
https://qldplasticsban.com.au/
https://www.qld.gov.au/environment/circular-economy-waste-reduction/recovery/reduction/plastic-pollution
https://www.qld.gov.au/__data/assets/pdf_file/0022/113368/plastic-pollution-reduction-plan.pdf
National Plastic Plan:
https://www.agriculture.gov.au/sites/default/files/documents/national-plastics-plan-2021.pdf
Sources: https://www.unep.org/news-and-stories/story/plastic-planet-how-tiny-plastic-particles-are-polluting-our-soil#:~:text=Microplastics%20can%20even%20be%20found,their%20health%20and%20soil%20functions; https://www.nationalgeographic.com/environment/article/microplastics-are-in-our-bodies-how-much-do-they-harm-us; https://sustainability.yale.edu/explainers/yale-experts-explain-microplastics; https://www.sciencedirect.com/science/article/pii/S0160412022001258?via%3Dihub; https://onlinelibrary.wiley.com/doi/10.1111/gcb.14020; https://www.mdpi.com/2305-6304/11/9/747; https://pubs.acs.org/doi/10.1021/envhealth.3c00052#; https://www.qld.gov.au/__data/assets/pdf_file/0022/113368/plastic-pollution-reduction-plan.pdf
