Plastics have long been dismissed by their critics as an environmental headache, but are difficult to completely avoid in the modern world.
The normal definition of microplastic is plastic fragments or fibres that measure 5mm or less. These are either a material that is already micro-sized when it enters the environment or, far more commonly, the result of the breakdown or shedding of a plastic material. Sometimes they can be added to products, as in the case of plastic microbeads added to cosmetic products.
Microplastics may contain any of more than 16,000 different plastic chemicals, of which at least 4200 (26 per cent) are considered “highly hazardous” to human health and the environment, including PFAS, bisphenols and phthalates. In addition, microplastics have a tendency to absorb and concentrate harmful pollutants in the environment.
This form of human-generated contamination is so pervasive that it is found in environments that would otherwise be considered pristine, such as the peaks of the highest mountains, Antarctic Sea ice, the North Pole and the Mariana Trench, the deepest point in the world’s oceans. It has colonised everywhere in the world, to a greater or lesser concentration, and this includes the human body.
The role of the plastics industry
In the period following World War II, plastic took off, aided by a consumer boom, coupled with industry-driven messaging encouraging a wasteful shift towards single-use disposables. At the end of life, most is landfilled or incinerated via waste-to-energy, a type of power generation that is more carbon-polluting than burning coal. The average global plastic recycling rate remains under 10 per cent.
More important from a microplastic perspective is the roughly 0.5 per cent that ends up in the oceans. Most of this problem occurs in Southeast Asia, with the Philippines in particular being a global blackspot. To tackle the problem at its source, the amount of plastic packaging could be reduced, waste collection could be improved, and more recycling infrastructure that serves poorer countries could be established. There are major differences between rich and poor countries in how plastic waste is managed. Among OECD (Organisation for Economic Co-operation and Development) nations, including Australia, the UK and Japan, 2019 figures showed that an average 6 per cent was “mismanaged and uncollected litter”, compared to 39 per cent outside the OECD.
Meanwhile, plastic production has doubled in the last 20 years, in an exponential growth curve, and an estimated 99 per cent is derived from fossil fuels. Production of virgin plastic was responsible for an estimated 5 per cent of the world’s greenhouse gas emissions in 2019, a share that is on track to grow dramatically.
Global plastic waste totals 400 million tonnes per year, and current trends would result in this figure nearly tripling to 1100 million tonnes by 2050. This issue is now being framed as a “plastic pollution crisis”.
In November 2024, negotiations on a global plastics treaty kicked off in the South Korean city of Busan, initiated by the United Nations. So far, no consensus position has been reached, largely due to resistance from oil producers such as Saudi Arabia, Russia and Iran. Yet more than 100 countries support commitments to reduce plastic production.
Where do microplastics originate?
Plastic takes up to 500 years to decompose and, when this does occur, it breaks down into ever smaller pieces instead of disappearing.
The Great Pacific Garbage Patch is concentrated in two primary locations, the more well-known of which is roughly halfway between California and Hawaii. Nearly all of it is plastic, which is slowly broken down, to form microplastics, and smaller nanoplastics that are less than one micrometer or micron (a thousandth of a millimetre) in size. The soup-like consistency of this limbo for unwanted plastic makes collecting it a formidable challenge. The accumulation of plastic fragments has been found to be growing at a rapid rate.
Tracing the origin of oceanic plastic particles, several important sources can be identified.
Cosmetics companies add plastic microbeads to certain products such as face wash and hand soap due to their abrasive or exfoliant properties. Being deliberately added, they are the easiest of all to avoid, if shoppers take time to look at the ingredient lists.
Perhaps surprisingly, paint, largely in the form of polymers used in binders, has been identified by a 2022 study as the primary source of microplastics entering waterways and the oceans, constituting 58 per cent.
An important source of ocean microplastics is the fibres from synthetic clothing (polyester, acrylic and nylon) and part-synthetic blends. These are emitted during washing, especially from the first few washes. To reduce these releases, suggestions include washing clothing less, washing on cold, avoiding purchasing synthetics, using a Guppyfriend washing bag or installing a microplastic filter on the drain hose line.
Tyre wear is another important microplastic generator, responsible for an estimated quarter of these particles entering the environment. Heavier vehicles such as four-wheel drives and electric vehicles tend to do more shedding. Tyre designers have been working on prototypes that are less prone to this problem.
Plastic artificial turf releases plastic fragments and is potentially linked to cancer and other serious health issues. Guppyfriend sells special drain filters that are installed on the edges of sports fields with synthetic turf.
Nurdles are tiny, lentil-sized plastic resin pellets used as a manufacturing feedstock, which are microplastic-sized when they sit in storage at plastic factories. Due to their tiny size, it is easy for some to escape into the surrounding environment. The group Environmental Justice Australia has drawn attention to the accumulation of nurdles in Melbourne’s Port Phillip Bay.
Human exposure
Three primary routes for people to take in microplastics are via food, drink and breathing in airborne particles.
When it comes to eating, exposure sources include plastic packaging, food-storage containers, utensils and plates. A 2025 Chinese study on plastic takeaway containers found that exposure may alter the gut biome, potentially triggering inflammation linked to a higher risk of heart failure.
Recommendations for minimising food exposure include:
- Swap plastic food-storage containers with glass.
- Avoid using plastic takeaway containers or otherwise transfer the food into a non-plastic container when you get home.
- Replace plastic cutting boards with wood or bamboo.
- Swap plastic utensils with wood or metal.
- Don’t heat plastic in the microwave. Always remove food from a pla