Microplastics are extremely small pieces of plastic debris that can measure up to 5mm in length, which is about the size of a sesame seed. However, most microplastics found are more commonly on the nanoscale, reaching < 1 micrometer (0.001mm) in size. For comparison, the thickness of a single sheet of paper is 0.05mm.
Generally, microplastics are the product of the whittling of larger plastic items in the environment such as discarded household rubbish, industrial discharge, or litter discarded into rivers. These larger plastic items are broken down into microplastics due to heat, oxidation, light and microorganisms. The rate and extent of the degradation of plastic varies depending on the environmental variables present. Microplastics also come in a smaller form called microbeads, which are commonly used in cosmetic products, such as facial washes and toothpastes.
Due to the fact that microplastics are more common in seawater because of littering and industrial waste, microplastic contamination is more common in seafood, particularly in shellfish. Mussels and oysters are at a much higher risk. This is because of the higher concentration of plastic in the water near the shore, which is where most oysters and mussels are found.
Microplastics are also present in other food and drinks we consume, such as sea salt, honey and beer. A recent study tested 15 brands of sea salt for microplastic contamination and discovered 600 microplastic particles per kg of salt while other studies found 660 microplastic fibres per kg of honey and 109 fragments per litre of beer. A pilot study conducted by researchers from the Medical University of Vienna discovered microplastics in the stool samples of 100% of the volunteers tested. While it was a small sample of just 8 individuals, the fact that they were spread across Asia and Europe indicates the global impact of the problem. The diet of the volunteers included liquids from plastic bottles and seafood.
Because microplastics originate from everyday plastic items all around the world, it is challenging to determine the exact sources of these microplastic particles found in such foods.
Because microplastics are able to absorb and release different types of chemical compounds, we should be concerned about what that means for our health. To date, few studies have been done on humans to determine how microplastics affect human health. It is speculated that the amount of microplastics that enter your body are small and will simply pass through your digestive tract. It remains to be known exactly how many plastics we consume are big enough to be causing us harm.
Although the effects of microplastics on human health are unclear, it is still wise to limit intake of food and beverages where microplastics are commonly found. Start by doing what is within your control. Consider limiting the use of plastic utensils and food packaging. Opt for glass bottles and metal or wooden utensils rather than plastic, and for paper-wrapped food rather than plastic wrapping, where possible.
Doing your best to limit the amount of plastic introduced into the food chain is another way you can contribute. When shopping, make choices where plastic packaging is limited so you are throwing less away and if it is not yet a common practice in your country, and to avoid buying cosmetic cleansers that contain microplastic beads.
If you accidentally ingested a piece of plastic, do not attempt to induce vomit as it can cause adverse choking and pains in your throat. Depending on the size of the plastic piece you swallowed, if it does not cause any discomfort when it went down your throat, you will most likely pass it out when you go to the toilet. On the other hand, if the plastic piece is sharp, it may damage your gut lining and cause internal bleeding. If you feel any discomfort or is worried after ingesting a plastic piece, it is better to head over to the accident & emergency department (A&E) and seek a doctor's advice.