Microplastics have become an unavoidable part of our world, sneaking their way into our oceans, air, and even the food we eat. These tiny plastic particles—less than 5 millimeters in size—are like the glitter of the pollution world: once they’re out there, you can never seem to get rid of them. They form from the breakdown of larger plastic waste and from microbeads in everyday products. As alarming as it sounds (and yes, it is), recent studies have shown that microplastics are now turning up in a wide range of foods, making them an uninvited guest at our dinner table.
In this article, we’ll take a closer look at which foods have the highest levels of microplastic contamination—backed by scientific research—and why this should have us all paying attention to what’s on our plates.
Seafood: A Major Source of Microplastic Exposure
Seafood has long been at the top of the list when it comes to foods contaminated with microplastics. Because of plastic pollution in the ocean, marine life is continuously exposed to microplastics, which they ingest either directly or indirectly by consuming smaller organisms. When humans eat seafood, we, too, ingest these plastics.
A comprehensive study published in Environmental Science & Technology in 2019 estimated that people who regularly consume shellfish may ingest as many as 11,000 microplastic particles per year. Another study conducted by Barrows et al. (2018) found that fish commonly sold in markets, including species such as tuna and sardines, contained microplastic particles. Although we typically remove the digestive systems of fish (where most of the plastic accumulates), research shows that small particles can migrate into muscle tissues, which we then consume.
Shellfish such as mussels, oysters, and shrimp are especially concerning since we often eat these animals whole, including their digestive tracts, where microplastics are most concentrated.
Sea Salt: Microplastic Contamination Linked to Ocean Sources
Salt, particularly sea salt, is another major food source of microplastic contamination. Since sea salt is harvested from ocean water, it directly reflects the level of plastic pollution in marine environments. In a 2018 study published in Environmental Science & Technology, researchers analyzed 39 salt brands from various countries and found that over 90% contained microplastics. Some samples contained as many as 600 microplastic particles per kilogram of salt.
Given that salt is such a common ingredient in nearly every meal, regular consumption could significantly increase our exposure to these plastic particles. Even rock salt and table salt are not completely free from contamination, as processing and packaging can introduce plastics into the product.
Beer: More Than Just Hops and Barley
Recent research has even found microplastics in beer. In a 2019 study by Liebezeit and Liebezeit, published in the journal Food Additives & Contaminants, 24 beer brands were analyzed, and microplastics were detected in every sample. Since water is the primary ingredient in beer, it is likely the main source of this contamination. However, other stages in the brewing process could also introduce plastics.
While the levels of microplastics in beer are relatively low compared to other sources like seafood or bottled water, regular consumption could still add to your overall exposure.
Honey: A Natural Sweetener With a Plastic Problem
Even honey, which is often regarded as a natural and pure product, is not immune to microplastic contamination. A study published by Schlesinger et al. (2020) in the journal Science of the Total Environment found microplastic particles in commercial honey samples. The likely source of this contamination is environmental, as bees are exposed to microplastics in the air, soil, and water while foraging for nectar. The study reported an average of 166 microplastic particles per kilogram of honey.
Given the wide use of honey as a sweetener, this is a troubling finding that demonstrates how deeply embedded microplastics have become in even the most natural food products.
Fruits and Vegetables: A Hidden Source of Microplastics
It may come as a surprise that fruits and vegetables can also be contaminated with microplastics. Research published by Li et al. (2020) in the journal Nature Sustainability found that microplastics can be absorbed by plants through their root systems. The study showed that plastic particles can migrate into edible parts of plants, meaning that produce like apples, carrots, and lettuce could contain microplastics.
Although more research is needed to fully understand how microplastics affect plant-based foods, this finding raises concerns about the broader contamination of our food supply, even in agricultural environments.
How Do Microplastics Get Into Our Food?
Microplastics enter our food in several ways, primarily through environmental contamination and food production processes:
- Environmental contamination: Microplastics are pervasive in oceans, rivers, soil, and the air. They are introduced into the food chain when marine organisms ingest plastic particles, or when plants absorb them from polluted soils and water sources.
- Processing and packaging: Food processing equipment, plastic packaging, and transportation methods can introduce microplastics into the final product. For example, bottled water can become contaminated with microplastics during the manufacturing process.
What Are the Health Risks of Microplastics?
Microplastics are a widespread and growing problem, infiltrating not only our oceans but also the food we eat. From seafood and salt to bottled water and even honey, microplastic contamination is now a reality we must confront. While reducing plastic use and improving waste management are critical long-term solutions, individuals can take steps to reduce their exposure, such as avoiding excessive use of bottled water and choosing foods with less plastic packaging.
Understanding the sources of microplastics in our diet is a crucial first step toward making informed choices that can help minimize the health risks associated with this pervasive pollutant.