Beer, chicken, salmon—all of these have something in common. Sure, they're all delicious. But we were thinking of something much more alarming. They all likely contain microplastics.
When you read the word microplastics, you probably think of fish and bottled water. But a new study shows just how prevalent they are in food we buy at the grocery store.
Researchers at the Ocean Conservancy and University of Toronto tested 16 protein types, including seafood, poultry, pork, beef, tofu, and three plant-based meat alternatives, and found that 88 percent of them contained microplastics. This number was much higher than expected.
"Seafood has traditionally been a big focus of scientific research, but we are starting to see it is not just a problem limited to the ocean," said researcher Madeleine Milne, who conducted the study while at the Rochman Lab at the University of Toronto.
Before we delve into how these tiny particles get in our food, let's discuss what they are.
What Are Microplastics?
Plastic can be made from a variety of materials like polymers, oil, and natural gas. It's used to make anything from disposable water bottles and packaging to clothing and cosmetics. When items that contain plastic break down, they shed microplastics, which are small fragments less than 5 mm in diameter. And while plastic can take hundreds of years to decompose, it will release microplastics through daily usage.
A study published in Scientific Reports found that microplastics can be produced from activities like cutting, twisting, or tearing open plastic packages. Just think about your grocery bags, loaves of bread, and bottles of beer and soda. Any time they are ripped, they're likely releasing microplastics.
And there are even smaller particles called nanoplastics. A recently published research in the Proceedings of the National Academy of Sciences shows that a liter of bottled water can contain 110,000 to 400,000 particles of nanoplastics, which is much higher than experts previously thought.
How Do Microplastics Get Into Food?
While we often hear about microplastics polluting fish in the ocean, they also end up in other environments. "Microplastics have been documented to contaminate air, water and sediment (soil), all of which may be pathways for transfer to land animals and plant-based food sources," Milne said.
The study found that while there wasn't a significant difference between land and sea proteins, there were significantly more microplastics found in highly processed products like plant-based burgers, chicken nuggets, and tofu.
"This could be from machinery or conveyer belts, other plastic surfaces that the product comes in contact with, or even airborne fibers in the processing facility," she added.
Microplastic fibers, which derive from textiles often made from polyester, were the most abundant type of microplastics found in Milne's study. "Our clothing is a common source of microfibers, and while microfibers can shed from them any time, they are shed in greater quantities through the laundering process," she said. "Unfortunately, all the microfibers shed in a washing machine instantly enter our water supply and easily get into the environment from there."
Health Concerns Around Microplastics
Milne said that the effects of microplastics on humans is still uncertain. This is why they wanted to study common foods, like meat from the grocery store. And given that plastic is made from a variety of materials like polymers and chemical additives, it's difficult to know exactly how they affect humans.
"We have experimentally and in the field observed a diverse suite of hazards associated with microplastics," said Dr. Win Cowger, research scientist at the Moore Institute for Plastic Pollution Research. One study said that some microplastics should be able to penetrate organs.
And because the research on proteins shows that highly-processed foods have higher levels of microplastics, this could have implications for populations that eat more processed protein, according to Dr. Cowger.
Can You Avoid Microplastics?
"Our results suggest that reducing microplastic consumption cannot be solved by personal choice at the grocery store," said Milne. She added that microplastics have been found in anything from salt and honey to apples, cucumbers, and potatoes. Instead, she recommends supporting more large-scale efforts to reduce microplastic contamination in the first place.
