A Spoonful of Plastic?

Think about your most recent meal. Maybe it was a bowl of cereal, a sandwich, or sushi. No matter what was on the menu, your food probably contained an ingredient you weren’t planning on eating: plastic.

Millions of tons of plastic waste ends up in the environment each year. Over time, it crumbles into small pieces called microplastic. These plastic fragments are less than 5 millimeters (0.2 inches) long, ranging from roughly the length of a grain of rice down to bits so tiny they’re invisible to the naked eye. Microplastic has been found nearly everywhere on Earth—including in our food, our drinking water, and our bodies. Scientists recently estimated that people may ingest as much as 5 grams (0.2 ounces) of microplastic—roughly the amount in a credit card—every week!

Researchers are studying what happens to plastic in our bodies as well as its effects on our health. Meanwhile, there are steps we can take to cut down on plastic in our diets—and the amount making its way into the environment.

Think about your latest meal. Maybe it was a bowl of cereal, a sandwich, or sushi. Whatever it was, it probably contained an unwanted ingredient: plastic. 

Millions of tons of plastic waste ends up in the environment each year. Over time, it crumbles into small pieces called microplastic. These plastic fragments are less than 5 millimeters (0.2 inches) long. The largest are about the length of a grain of rice. Others are tiny enough to be invisible to the naked eye. Microplastic has been found nearly everywhere on Earth. It’s even in our food, our drinking water, and our bodies. Scientists recently estimated that people may swallow as much as 5 grams (0.2 ounces) of microplastic every week. That’s about the amount in a credit card! 

What happens to plastic in our bodies, and how does it affect our health? Researchers are studying those questions. But we can also take steps to cut down on plastic in our diets—and the amount ending up in the environment.  

Plastic is all around us. It’s used to produce everything from clothing and toys to cars and electronics. This versatile material is made from polymers—large molecules that consist of repeating units. Other chemicals called additives give plastic properties like strength, color, transparency, or flexibility.

Plastic is durable and inexpensive to produce. But these same characteristics make it a big pollution problem. Unlike wood, paper, or metal, discarded plastic products don’t fully biodegrade, or naturally break down. Instead, they disintegrate into microplastic. Microplastic also comes from synthetic fabrics, like polyester, nylon, and spandex. These lab-made materials shed tiny plastic fibers when people wear or wash them. All those plastic particles may stick around in the environment for hundreds or thousands of years.

Wind and water transport these plastic bits all over the world (see From Shore to Sea). Scientists have found microplastic just about everywhere they’ve looked: beaches, forests, remote mountaintops, caves, Antarctic ice, and even deep-sea trenches.

Microplastic can blow or flow into drinking water sources. It can be absorbed by plants (which animals or people might eat) or consumed by animals. When people eat food contaminated with plastic, it enters our bodies as well.

Plastic is all around us. It’s used in many products, including clothing, toys, cars, and electronics. This handy material is made from large molecules called polymers. Polymers consist of repeating units. Plastic contains other chemicals called additives. They give it features like strength, color, transparency, or flexibility.  

Plastic is long-lasting and inexpensive to produce. But those features also make it a big pollution problem. Wood, paper, and metal fully biodegrade, or naturally break down. But plastic products don’t. Instead, they crumble into microplastic. Microplastic also comes from synthetic fabrics. These lab-made materials include polyester, nylon, and spandex. When you wear or wash them, they shed tiny plastic fibers. All those plastic particles may stay in the environment for hundreds or thousands of years. 

Wind and water carry these plastic bits all over the world (see From Shore to Sea). Scientists have found microplastic just about everywhere. It’s in forests, beaches, remote mountaintops, caves, Antarctic ice, and even deep-sea trenches.

Microplastic can blow or flow into drinking water sources. Animals can drink it, or plants can absorb it. Then animals or people might eat the plants. When people eat food that contains plastic, it enters our bodies too.

Plastics researcher Thava Palanisami works at the University of Newcastle in Australia. He and his colleagues wanted to understand how much plastic people consume on a regular basis. They combined data from 59 studies examining the amount of plastic in several common foods and beverages, including tap and bottled water, fish, shellfish, salt, sugar, and honey.

The team combined the studies’ data with estimates of how much of each item people regularly consume. That brought them to the startling total of up to a credit card a week. “We were very surprised by the amount of plastics we’re exposed to in our daily lives through food and water,” says Palanisami.

A 2019 study by another team looked at a similar mix of foods and beverages to analyze the number of plastic pieces people ingest. The result: The average person swallows around 45,000 microplastic fibers or particles every year from just those few sources. Bottled water stood out as particularly contaminated, averaging more than 20 times as much microplastic as tap water.

How much plastic do people consume on a regular basis? Thava Palanisami wanted to find out. He’s a plastics researcher at the University of Newcastle in Australia. He and his colleagues looked at data from 59 studies. These studies examined the amount of plastic in common foods and beverages. They included tap and bottled water, fish, shellfish, salt, sugar, and honey.

The team put the studies’ data together. They added estimates of how much of each item people regularly consume. That gave them the shocking total of up to a credit card a week. “We were very surprised by the amount of plastics we’re exposed to in our daily lives through food and water,” says Palanisami. 

Another team did a study in 2019. They looked at a similar mix of foods and beverages to figure the number of plastic pieces people consume. They found that the average person swallows around 45,000 microplastic fibers or particles every year. And that’s from just those few sources. Bottled water stood out for being contaminated. It averaged more than 20 times as much microplastic as tap water. 

Both analyses assessed only a few foods and beverages because those were the only items with enough data available. So these studies don’t give a full picture of all the plastic we eat. “You can find plastic in most foods,” says David Love, an environmental health researcher at Johns Hopkins University in Maryland. For example, microplastic has been detected in fruits, vegetables, and poultry, but the amounts haven’t been thoroughly measured yet.

Both studies included only a few foods and beverages. That’s because enough data wasn’t available for other items. So these studies don’t reveal all the plastic we eat. “You can find plastic in most foods,” says David Love, an environmental health researcher at Johns Hopkins University in Maryland. For example, microplastic has been found in fruits, vegetables, and poultry. But the amounts haven’t been fully measured yet.  

This research leads to another big question: What happens to the microplastic that we eat? “Larger microplastic probably passes through our digestive system,” says Love. New studies have confirmed the presence of microplastic in human poop—fragments were found in every sample, from people in several different countries.

That doesn’t mean larger microplastic bits are harmless, though. Common plastic additives have been linked to heart disease, diabetes, cancers, and reproductive problems in people. If those chemicals leach out as plastic pieces travel through the digestive system, they could pose health risks.

This research raises another big question. What happens to the microplastic that we eat? “Larger microplastic probably passes through our digestive system,” says Love. New studies have found microplastic in human poop. The tiny fragments were in every sample, from people in several countries. 

But that doesn’t mean larger microplastic bits are harmless. Common plastic additives have been linked to health problems in people. These include heart disease, diabetes, cancers, and reproductive problems. As plastic pieces travel through the digestive system, those chemicals might be released. Then they could pose health risks. 

Smaller, invisible microplastic presents additional concerns. Unlike bigger bits, “these tiny pieces can move into the bloodstream and spread throughout the body,” says Love. “It’s probably not going to make you sick right away, but research suggests long-term exposure can cause problems.” Studies in animals show that very small microplastics can disrupt hormones (chemicals that regulate body functions), weaken the body’s disease-fighting immune system, and increase cancer risk.

Although microplastic’s health effects are still being studied, says Love, “we’ve learned enough to know that we shouldn’t be eating plastics.” Palanisami, who calculated how much plastic people consume, agrees. “Ultimately, we want zero plastics in our diet,” he says.

Smaller, invisible microplastic causes other concerns. Unlike bigger bits, “these tiny pieces can move into the bloodstream and spread throughout the body,” says Love. “It’s probably not going to make you sick right away, but research suggests long-term exposure can cause problems.” Animal studies show that microplastics can disrupt hormones, or chemicals that control body functions. They can also weaken the body’s disease-fighting immune system and increase cancer risk. 

Microplastic’s health effects are still being studied. But Love says, “we’ve learned enough to know that we shouldn’t be eating plastics.” Palanisami, who figured out how much plastic people consume, agrees. “Ultimately, we want zero plastics in our diet,” he says. 

Because microplastic is so widespread, it may be impossible to avoid completely. But certain steps could reduce how much we consume. Drinking tap instead of bottled water whenever possible is a big one, since bottled water is more contaminated. Also, plastic packaging can transfer microplastic particles and additives to food. Fresh foods or items packaged in glass or paper may be better options. They also cut down on plastic trash, which turns into microplastic.

Microplastic is everywhere, so we may not be able to avoid it completely. But certain steps could reduce the amount we consume. Bottled water is more contaminated than tap water. So drink tap water whenever possible. Also, plastic packaging can pass microplastic particles and additives to food. Choose fresh foods or items packaged in glass or paper. They also cut down on plastic trash, which turns into microplastic.

Rejecting plastic packaging is a win-win, says Love: It reduces the plastic you ingest and the amount that ends up in the environment. “We’re seeing that when we throw something away, there is no ‘away,’” says Love. “The problems with plastic are reaching us here and now.”

Palanisami hopes his work will inspire change. “The image of possibly consuming up to a credit card’s worth of plastic every week is something we want people to have in their minds as they make decisions,” he says. “The more plastic we buy, the more ends up in our food.”

Rejecting plastic packaging is a win-win, says Love. It not only reduces the plastic you consume. It also reduces the amount that ends up in the environment. “We’re seeing that when we throw something away, there is no ‘away,’” says Love. “The problems with plastic are reaching us here and now.” 

Palanisami hopes his work will bring about change. “The image of possibly consuming up to a credit card’s worth of plastic every week is something we want people to have in their minds as they make decisions,” he says. “The more plastic we buy, the more ends up in our food.”