Chopping microplastics straight into dinner

People are constantly being reminded of the dangers of plastic pollution in the ocean. But what about the plastic particles lurking in the kitchen?

Recent research has brought to light the health risks associated with the existence of microplastics on our chopping boards, revealing a hidden danger that hits closer to home.

Microplastics are small plastic pieces measuring less than five millimetres long which can be harmful to the ocean and aquatic life, but they could also find their way into homes and commercial kitchens shed from various sources even the chopping boards used to prepare meals.

According to a study published in ACS’ Environmental Science & Technology, chopping vegetables on wooden and plastic boards could potentially generate tens of millions of microparticles annually.

Despite this, a toxicity test indicated that microparticles from polyethylene or wood released during the chopping process did not significantly affect the survival of mouse cells.

The study showed that continued use of chopping boards for food preparation tasks like mincing, slicing and chopping with sharp knives can gradually create grooves and slash marks, inadvertently releasing microplastics from the board's surface.

Recently, research also revealed that certain plastic materials used for boards, including polypropylene and polyethylene can shed nano and micro-sized flecks when cut with knives.

However, these studies did not evaluate the potential quantity of microplastics generated in practical food preparation situations, which is crucial information as these particles could potentially pose health risks when consumed.

Therefore, researchers at North Dakota State University conducted a study to determine the quantity of microplastic particles released from chopping boards and studied the impact of chopping styles and board materials as well as the potential toxicity of the produced particles.

The research involved chopping experiments carried out by different individuals using the same steel knife on polyethylene, polypropylene and wooden chopping boards.

Both dry chopping board experiments and chopping with carrots, simulating real-life scenarios were conducted.

Following each experiment, the knife and board were rinsed with water previously tested for microplastics and the produced microplastic particles (or wooden microparticles) were filtered out to collect them.

Subsequently, these particles were examined using microscopy and their weight was determined.

The researchers discovered that the chopping patterns had a significant impact on the mass of polyethylene microplastics.

Furthermore, the choice of chopping board material influenced the mass of microparticles released during chopping.

They found that wooden chopping boards displayed a higher mass of released wooden microparticles compared to polyethylene and polypropylene chopping boards.

Chopping carrots on polyethylene boards led to a higher release of microplastics compared to chopping on an empty board, attributed to increased pressure during chopping.

In terms of shape and size, spherical microplastics smaller than 100 μm were the most frequently observed.

In summary, the researchers estimated that food preparation using chopping boards could potentially expose an individual to tens of millions of microplastic particles yearly.

The real concern about microplastics on chopping boards lies in their potential health risks.

When microplastics end up in the food, it can be ingested unknowingly and could affect various systems in the human body, including the digestive, respiratory, endocrine, reproductive and immune systems.

When ingested, microplastics can lead to physical irritation of the gastrointestinal tract, resulting in inflammation and various gastrointestinal symptoms.

According to the United States National Institutes of Health website, ingesting microplastics could disrupt the balance of the intestinal microbiome, leading to an imbalance between beneficial and harmful bacteria, which can contribute to gastrointestinal issues such as abdominal pain, bloating, and changes in bowel habits.

Additionally, microplastics can carry and introduce environmental toxins into the body when ingested, leading to symptoms such as nausea, vomiting, and abdominal pain.

In terms of the respiratory system, inhaling microplastics can cause oxidative stress in the airways and lungs, leading to respiratory symptoms like coughing, sneezing, and shortness of breath.

These symptoms are a result of inflammation and damage to the respiratory system.

Furthermore, exposure to microplastics can lead to endocrine disruption, causing various endocrine disorders, including metabolic and developmental issues, as well as reproductive disorders like infertility and miscarriage. Microplastics can also act as carriers for environmental toxins like bisphenol A, contributing to diseases of the endocrine and reproductive systems.

Microplastics may also impact the immune system, potentially leading to chronic inflammation and changes in homeostasis. In animal experiments, they were found to activate the immune response, further highlighting potential health risks.

Experimental studies with human cells and animals have shown that microplastics can have adverse effects by causing inflammation, oxidative stress, lipid metabolism disturbances, gut microbiota dysbiosis, and neurotoxicity.

The exact exposure levels and loads of microplastics that affect human health are still being researched, and more studies are needed to provide a comprehensive understanding of the health implications of microplastic exposure.

To minimise risks of microplastics on your chopping boards, opt for cutting boards made from natural materials like wood or bamboo, which are less likely to release microplastics.

Other ways to minimise risks are by regularly cleaning the chopping board with mild soap and water instead of harsh chemicals or excessive scrubbing and be mindful when preparing and handling food.