Microplastic in Our Food

From packaging material to disposable cutlery, today’s food system is no stranger to plastic. In fact, it is so pervasive that tiny particles even end up in the food we eat. These particles, known as microplastics, often go unnoticed because of their small size and the lack of detection technology. Let’s take a look at how they enter our food chains and what can be done to get rid of them.

What are microplastics?

Microplastics are small plastic particles that range from 0.1 to 5000 micrometres.¹ Depending on how they were created, microplastics can be classified as either primary or secondary. Primary microplastics are plastics that are purposefully manufactured to be their intended size for use in products such as detergents and cosmetics. Secondary plastics are created because of larger pieces of plastic, derived from a wide range of sources, breaking down over time to form smaller particles.¹ Microplastics in food first became a cause of concern around 50 years ago when they were discovered as a pollutant in marine ecosystems. Since then, they have been found in freshwater environments, sediments, soils, air, and ice from remote polar regions.² Even the Mariana Trench, the deepest oceanic trench on earth, was found to contain between 200 and 2200 pieces of microplastic particles per litre of sediment.² These particles are transported through our sewage systems and become part of the water cycle. Once part of the water cycle, microplastics are dispersed into the air we breathe and the food we consume.

How do they end up in our foods?

Most microplastics find their way into our food chains through fish and seafood. The particles aquatic animals consume end up in their guts but only last a short time. Therefore, unlike other substances such as mercury, microplastics do not accumulate over time. Since fish guts are not commonly consumed, plastic particles ingested by fish are not considered a direct risk to human health.³ Yet, debris-filled fish organs can end up in animal feed, making their way to our plates through animal-based foods.³ Additionally, filter-feeding marine animals such as mussels, oysters, and crabs, whose digestive tracts we do consume, can accumulate and pass on significant quantities of microplastic in humans.³ Food can also be contaminated by secondary microplastic particles during production and through packaging.⁴

How much microplastic do we consume?

It’s challenging to calculate how much microplastic we consume due to different quantification methods used across the globe. One Australian study published in 2021 estimated that the average person could potentially ingest 0.1 – 5 grams of microplastic per week.⁵ While this may sound alarming, this conclusion is based on numerous assumptions and estimates. And the amount of microplastic consumed by an individual is impacted by a host of factors such as their demographics, cultural heritage, and geographical location.⁵

What are the health risks?

Like fish, our bodies do not accumulate microplastics. More than 90% of the ingested microplastic particles can be eliminated through our faeces.¹ But despite coming into contact with our bodies for only a short period of time, microplastics can cause adverse health effects. Preliminary research on the subject indicates that consuming microplastic particles can lead to negative health effects such as inflammatory response, toxicity resulting from the chemicals present in them, and the disruption of the gut microbiome.⁵ However, scientists do not fully understand how microplastics interact with our bodies. Despite some studies focusing on individual cases, these results cannot be applied to the general population without further research.⁶

Is a microplastic-free future possible?

Microplastic particles will continue to contaminate the food chain as long as plastic (as we know it) remains pervasive in our environments. Currently, microplastic contamination is not considered a serious food safety concern. However, if it were to become one in the future, governments may introduce safety checks along the supply chain, similar to how food products are already scanned for physical and chemical contaminants.

Microplastic contamination can, however, be reduced through certain actions before it becomes a serious food safety issue. For instance, primary microplastics found in fertilisers, pesticides, cosmetics, detergents, and paints can be replaced with less harmful materials. Stricter recycling and waste separation protocols can prevent larger pieces of plastic from ending up in freshwater environments.⁷ Microplastic removal strategies such as absorption, ultrafiltration, and membrane technology can help improve the quality of polluted waters, and the development of food-grade biodegradable plastics can help eliminate secondary microplastics from our foods to a certain extent.^7,8

The plastic problem may be huge, but there is reason to hope. From fungi that can eat plastic to robo-fish programmed to remove microplastics from the ocean and a magnetic powder that can capture tiny fragments of plastic in wastewater facilities, microplastics may not be on our dinner plates forever.