We are living in the plastic age. Plastic is all around us, from the food packaging we use to the polyester clothes we wear, to even the construction material that is being used in our homes, plastic is everywhere. This has today translated to the alarming reality that plastic is now even present inside of us. Over the years, degrading plastic materials slowly turn into microplastics. Plastic is not biodegradable and as it ages it gets broken down into minute pieces that are harmful to the environment. Recent studies have already shown that microplastics are today even found in our food, especially seafood (1). While it still remains unclear whether or not these microplastics have an impact on our health, we still cannot disregard the possibility that they must be having some type of effect on our health. We take a closer look at the presence of microplastics in foods and how do they affect your health.
What Exactly are Microplastics?
Microplastics are the tiny pieces of plastic that are found freely in the environment. Microplastics are typically defined as particles of plastic that are smaller than 0.2 inches or 5 mm in diameter. Microplastics get created either when bigger pieces of plastic get broken down in the environment or they can also be produced as small plastics, to begin with, for example as microbeads which are added to exfoliants and toothpaste. With the prevalence of plastic in our lives, microplastics have become common in rivers, oceans and the soil also often being consumed by animals.
In the 1970s, many research studies were done that looked at the levels of microplastics present in the oceans. It was found that some of the highest levels of microplastics were present in the Atlantic Ocean, just off the coast of the United States. Since the 70s, the world has witnessed a drastic increase in the use of plastic and there is now much more plastic present in our rivers and oceans. It is estimated that nearly 8 million metric tons or 8.8 million tons of plastic waste are thrown into the ocean every year. While a majority of this plastic remains floating at sea, the rest of it has either washed ashore or sunk to the bottom of the sea (1).
Microplastics Present in Food
Microplastics are today found in all types of different environments, and the food we eat is no longer an exception. A study done by the East China Normal University looked at 15 types of different sea salt brands, and the study found that there were 273 microplastic particles found per pound of salt or 600 particles of microplastics per kilogram of sea salt.
Other studies were done by the MarChem Consult in Germany and the Plymouth Marine Laboratory in the United Kingdom found nearly 660 microplastic fibers per kilogram of honey and 109 fragments of microplastic per liter of beer. However, while microplastic was present in these food sources, the most affected source of food is seafood. This is because microplastics are most commonly found in seawater and are then consumed by fish and other marine organisms, which are then consumed by humans (1).
A study done by the University of California, Davis, found that microplastics are even present in organisms that live in the deep sea, thus suggesting that microplastics are also affecting the remotest of species. Furthermore, it has been found that oysters and mussels are at a much higher risk of getting contaminated by microplastics as compared to other species. For example, a study by the Laboratory of Environmental Toxicology and Aquatic Ecology in Belgium found that oysters and mussels that are produced for human consumption had 0.37-0.48 particles of microplastics present per gram. This essentially means that shellfish consumers are likely to ingest nearly 11,000 particles of microplastics every year (1).
How do Microplastics Affect your Health?
Microplastics are a type of microparticles and have been found to pass through the intestines to the bloodstream and also into other organs. While there have been many studies done that have positively proven the presence of microplastics in our food chain, there still remains a lot of confusion about whether microplastics affect our health and if so, what impact they have on our health. Very few studies have till date actually examined how microplastics impact human health and whether or not they cause any diseases. Nevertheless, it has been found that the presence of phthalates, which is a certain type of chemical used in plastics to make them flexible, are present in microplastics and phthalates increase the growth of breast cancer cells (2). However, this research was only carried out in a petri dish, which is why the results of this study cannot be generalized to humans as well.
Another study also looked at the impact microplastics has on laboratory mice. When microplastics were fed to mice, the particles accumulated in the kidneys, intestines, and the liver and also increased the levels of oxidative stress molecules found in the liver. Microplastics also boosted the level of a particular molecule that could be potentially toxic to the brain. A study done by the Roswell Park Cancer Institute in New York found that plastic fibers are present in over 85% of human lungs that were studied. Looking at the results, the researchers proposed that this was due to the presence of microplastics in the air. Other studies have also shown that microplastics present in the air may also cause lung cells to produce certain types of inflammatory chemicals, though this study was only done in test tubes by the Napier University in Scotland.
In the last so many years, BPA or bisphenol A, has been the best-studied chemical present in plastics (3). BPA is found commonly in food storage containers or plastic packaging and has the potential to leak into our food as well (3). Some evidence has shown that BPA interferes with reproductive hormones in women (3).
Can you Avoid Microplastics in Food?
Apart from seafood, microplastics are found in many different types of food sources. However, it still remains unclear how microplastics affect human health.
It has been found that the highest levels of microplastics are found in fish, especially shellfish (1). However, since the impact of microplastics on human health remains unknown, it is not necessary that you need to avoid having shellfish altogether. Nevertheless, it would be recommended that you consume high-quality shellfish from known and reputable sources only.
The other factor in which Microplastics can affect you is that some types of plastics can also leak into the food source from packaging. So, reducing the use of plastic food packaging will also reduce your intake of microplastics, and it will also be good for the environment.
Microplastics are present throughout our environment today, including the air, water and even our food sources. Seafood, especially shellfish, is known to have very high concentrations of microplastics that has been shown to accumulate in the body after having foods contaminated with plastics (1). It remains unclear how microplastics affect human health, though studies were done on animals and test tube studies have shown that they are likely to have negative effects. Reducing the use of plastic food packaging and having high-quality seafood is one of the effective ways of reducing your consumption of microplastics and also reducing the presence of plastic in the environment.
- Andrady, A.L., 2011. Microplastics in the marine environment. Marine pollution bulletin, 62(8), pp.1596-1605.
- Wright, S.L., Thompson, R.C. and Galloway, T.S., 2013. The physical impacts of microplastics on marine organisms: a review. Environmental pollution, 178, pp.483-492. Hidalgo-Ruz, V., Gutow, L., Thompson, R.C. and Thiel, M., 2012. Microplastics in the marine environment: a review of the methods used for identification and quantification. Environmental science & technology, 46(6), pp.3060-3075.
- Thompson, R.C., Moore, C.J., Vom Saal, F.S. and Swan, S.H., 2009. Plastics, the environment and human health: current consensus and future trends. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526), pp.2153-2166.
- Wright, S.L. and Kelly, F.J., 2017. Plastic and human health: a micro issue?. Environmental science & technology, 51(12), pp.6634-6647.
- Galloway, T.S., 2015. Micro-and nano-plastics and human health. In Marine anthropogenic litter (pp. 343-366). Springer, Cham.
- Sharma, S. and Chatterjee, S., 2017. Microplastic pollution, a threat to marine ecosystem and human health: a short review. Environmental Science and Pollution Research, 24(27), pp.21530-21547.