When he was 7 years old, Cash Daniels took a trip with his family to Daytona Beach, Florida. Walking on the sand, he picked up a piece of trash that would change his life: a plastic straw.

“Earlier that day, I’d seen a manta ray and a sea turtle swimming in the ocean,” he says. “So I made the connection that the plastic straw might harm those animals.”

If that straw had found its way into the surf, a marine creature might have swallowed it whole or some combination of heat, ocean waves, sand abrasion, and UV rays from the sun would eventually have broken it down into tiny microplastics, which scientists say are rapidly accumulating in the environment—and, startlingly, in the bodies of humans.

When Cash returned home to Chattanooga, Tennessee, he did some research and learned that most plastic in the ocean comes from rivers—like the Tennessee River, which flows through his hometown and is one of the most plastic-polluted rivers in the world. Now 15, he’s led river cleanups for the past eight years, removing more than 45,000 pounds of trash and becoming known as “The Conservation Kid.”

“With plastic pollution, I feel like anyone can make a difference,” he says. “Anyone can get outside and pick up a piece of plastic. Anyone can use a reusable cup or straw.”

Cash Daniels took a trip with his family to Daytona Beach, Florida. He was 7 years old. Walking on the sand, he picked up a piece of trash that would change his life. He found a plastic straw.

“Earlier that day, I’d seen a manta ray and a sea turtle swimming in the ocean,” he says. “So I made the connection that the plastic straw might harm those animals.” If that straw had found its way into the surf, a marine creature might have swallowed it whole.

Plastic is broken down into smaller pieces by a combination of heat, ocean waves, sand abrasion, and UV rays from the sun. Scientists say these tiny microplastics are rapidly accumulating in the environment. They are even being found in the bodies of humans.

When Cash returned home to Chattanooga, Tennessee, he did some research. He learned that most plastic in the ocean comes from rivers. The Tennessee River, which flows through his hometown, is one of the most plastic-polluted rivers in the world. Now 15, he’s led river cleanups for the past eight years. He has helped remove more than 45,000 pounds of trash and is now known as “The Conservation Kid.”

“With plastic pollution, I feel like anyone can make a difference,” he says. “Anyone can get outside and pick up a piece of plastic. Anyone can use a reusable cup or straw.”

If plastic seems to be ubiquitous, that’s because it is. In the past five years, scientists have discovered plastic near the summit of Mount Everest, in the breath of bottlenose dolphins, and in human organs, including the liver, kidney, and brain. And in February, a group of researchers at the University of New Mexico raised alarm with new findings showing that the average human brain contains the same amount of plastic used to make a disposable spoon. While it’s unclear exactly how this could affect our health, scientists are racing to find out.

“We don’t know when critical health effects really start to emerge from plastic exposure,” says Matthew Campen, a toxicologist who leads the University of New Mexico lab. “Is 20 years a critical time point? Is it 50? Are we seeing the health effects now, and we just don’t realize it? Those concerns motivate our work.”

If plastic seems to be everywhere, that’s because it is. In the past five years, scientists have discovered plastic near the summit of Mount Everest and in the breath of bottlenose dolphins. Plastic has been found in human organs, including the liver, kidney, and brain. And in February, a group of researchers at the University of New Mexico raised alarm with new findings showing that the average human brain contains the same amount of plastic used to make a disposable spoon. It’s unclear exactly how this could affect our health.  Scientists are in a race to find out.

“We don’t know when critical health effects really start to emerge from plastic exposure,” says Matthew Campen, a toxicologist who leads the University of New Mexico lab. “Is 20 years a critical time point? Is it 50? Are we seeing the health effects now, and we just don’t realize it? Those concerns motivate our work.”

A Belgian American chemist named Leo Baekeland first synthesized plastic in 1907 (see “A History of Plastic,” below). But the plastics industry began to take off in the U.S. only during World War II (1939-45), when, with other materials in short supply, plastic became a critical part of everything from parachutes to airplane windows. After the war, manufacturers began making plastic products for consumers, and by the 1950s, plastic was present in everything from toys to electronics to Tupperware. Since the 1960s—as cheap, convenient plastic products have become the norm for most of the world—plastic production has doubled every 10 to 15 years.

Scientists estimate that we’ve recycled only about 9 percent of all the plastic ever produced; the wide array of plastic types and the high cost of recycling can make it a complicated and expensive process. Instead, as plastic objects age, they break down and shed tiny particles called microplastics, which are no larger than a grain of rice, and even smaller nanoplastics, no larger than the diameter of a human hair.

A Belgian American chemist named Leo Baekeland first synthesized plastic in 1907 (see “A History of Plastic,” below). But the plastics industry began to take off in the U.S. only during World War II (1939-45). Other materials were in short supply because of the war. Plastic became a critical part of everything from parachutes to airplane windows. After the war, manufacturers began making plastic products for consumers. By the 1950s, plastic was present in everything from toys to electronics to Tupperware. Plastic production has doubled every 10 to 15 years since the 1960s. Plastic products have become the norm for most of the world because they are cheap and convenient.

Scientists estimate that we’ve recycled only about 9 percent of all the plastic ever produced. Recycling is an expensive and complicated process, in part because of the wide array of plastic types. Instead, as plastic objects age, they break down and shed tiny particles called microplastics, which are no larger than a grain of rice, and even smaller nanoplastics, no larger than the diameter of a human hair.

“We use plastics in areas or in ways that lend themselves to the production of microplastics or to [their] breakdown over time,” says Jeffrey Farner, an engineering professor at the Florida A&M University-Florida State University College of Engineering.

For instance, more than one-third of plastic produced today is for packaging, including single-use items like food containers that largely end up as waste. Such products “break down into just an enormous number of micro- and nanoplastics,” Farner says.

Microplastics and nanoplastics end up in our air, soil, water, and food. The wear and tear on car tires, for example, produces particles that pollute the air and water. Clothes made of synthetic fibers, like acrylic or nylon, shed microplastics when they’re manufactured, washed, and worn. Microplastics filtered out of wastewater end up in sludge that’s then used as fertilizer. Plastic cigarette filters make their way to lakes and oceans, where they degrade over time.

“We use plastics in areas or in ways that lend themselves to the production of microplastics or to [their] breakdown over time,” says Jeffrey Farner, an engineering professor at the Florida A&M University-Florida State University College of Engineering.

For instance, more than one-third of plastic produced today is for packaging. These single-use items like food containers largely end up as waste. Such products “break down into just an enormous number of micro- and nanoplastics,” Farner says.

Microplastics and nanoplastics end up in our air, soil, water, and food. For example, the wear and tear on car tires produces particles that pollute the air and water. Clothes made of synthetic fibers, like acrylic or nylon, shed microplastics when they’re manufactured, washed, and worn. Microplastics filtered out of wastewater end up in sludge that’s then used as fertilizer. Plastic cigarette filters make their way to lakes and oceans, where they degrade over time.

Humans breathe in these particles and ingest them. Some research suggests fruits and vegetables absorb microplastics from the soil through their roots. Microplastics end up in the fish we eat when they mistake plastic pellets for food or eat smaller species that have consumed microplastics. The higher up the food chain an animal is, scientists say, the greater the concentration of microplastics that’s likely to be found inside it. Microplastics are also more common in highly processed food, potentially because of contamination from processing machinery or even workers’ clothing.

The University of New Mexico researchers found that as the amount of plastic in our world continues to increase, the amount inside our brains is multiplying too. Analyzing plastic in human tissue samples, they found that brain samples from 2024 had nearly 50 percent more microplastics than brain samples from 2016.

“This stuff is increasing in our world exponentially,” Campen says. “Even if we stop making plastics today, we will have a continued increase of micro- and nanoplastics in the environment for generations to come.”

Humans breathe in these particles and ingest them from the food we eat. Some research suggests fruits and vegetables absorb microplastics from the soil through their roots. Fish mistake plastic pellets for food or eat smaller species that have consumed microplastics. The higher up the food chain an animal is, scientists say, the greater the concentration of microplastics that’s likely to be found inside it. Microplastics are also more common in highly processed food because of contamination from processing machinery or even workers’ clothing.

The University of New Mexico researchers found that as the amount of plastic in our world continues to increase, the amount inside our brains is also increasing. They looked at  plastic in human tissue samples and found that brain samples from 2024 had nearly 50 percent more microplastics than brain samples from 2016.

“This stuff is increasing in our world exponentially,” Campen says. “Even if we stop making plastics today, we will have a continued increase of micro- and nanoplastics in the environment for generations to come.”

Other scientists have found microplastics in the waste of newborn babies, as well as in human blood, and have linked exposure to microplastics to reproductive issues and certain cancers. But for all the places they’ve found microplastics, and all the concern about health risks, a lot remains unknown—including the health effects of a majority of the chemicals in plastic, says Amelia Meyer, an environmental researcher at Stanford University.

“Synthetic plastic has 16,000 chemicals,” she says. “We’ve only identified a quarter of them as being hazardous, but we don’t even know the rest.”

And researchers are still trying to determine how plastic gets to the brain. The University of New Mexico team says that the tiny plastic particles we ingest might get absorbed through fat molecules. These fat molecules then make their way to the brain, which relies on fat to function. Now the scientists are trying to understand how much plastic is enough to start affecting human health.

“This is a big global question,” Campen says.

Other scientists have found microplastics in the waste of newborn babies, as well as in human blood.  Exposure to microplastics has been linked to reproductive issues and certain cancers. But a lot remains unknown about microplastics, including the health effects of a majority of the chemicals in plastic, says Amelia Meyer, an environmental researcher at Stanford University.

“Synthetic plastic has 16,000 chemicals,” she says. “We’ve only identified a quarter of them as being hazardous, but we don’t even know the rest.”

Researchers are still trying to figure out how plastic gets to the brain. The University of New Mexico team says that the tiny plastic particles we ingest might get absorbed through fat molecules, and the brain relies on fat to function. Now the scientists are trying to understand how much plastic is enough to start affecting human health.

“This is a big global question,” Campen says.

In recent decades, the world has started to take action to reduce plastic’s impact on the environment—and us. The United Nations is working with 175 countries to negotiate a global treaty focused on reducing plastic pollution, with the latest round of negotiations having taken place in Switzerland in August. And many nations already have policies of their own. In 2002, Bangladesh became the first country in the world to ban certain single-use plastic bags, which are difficult to recycle, and 90 other nations and territories have since followed suit. Over the past decade, several countries, including the U.S., have banned the manufacturing of products containing plastic microbeads, such as certain cosmetics and lotions. In 2021, the European Union banned the sale of some single-use plastic items, including plates, cutlery, and straws.

In recent decades, the world has started to take action to reduce plastic’s impact on the environment and humans. The United Nations is working with 175 countries to negotiate a global treaty focused on reducing plastic pollution. The latest round of negotiations took place in Switzerland in August. Many nations already have policies of their own. In 2002, Bangladesh became the first country in the world to ban certain hard-to-recycle single-use plastic bags, and 90 other nations and territories have since followed suit. Over the past 10 years, several countries, including the U.S., have banned the manufacturing of products containing plastic microbeads, such as certain cosmetics and lotions. In 2021, the European Union banned the sale of some single-use plastic items, including plates, cutlery, and straws.

Plastic regulations in the U.S. have largely fallen to states and local governments. Twelve states and more than 500 cities have implemented plastic bag bans. In the absence of federal policy, state and local governments are attempting to hold corporations accountable. Five states have passed laws requiring companies that produce plastic packaging to pay for the cost of recycling it. Several states and cities have sued companies including PepsiCo, Coca-Cola, and the kitchen goods company Reynolds for plastic pollution from beverage bottles and plastic bags and allegedly misleading claims about their recyclability. Many of these lawsuits are still ongoing, but results have so far been mixed. A judge dismissed New York State’s lawsuit against PepsiCo for plastic pollution, while Minnesota received a settlement from Reynolds to help pay for plastic cleanup efforts.

Plastic regulations in the U.S. are mainly up to states and local governments. Twelve states and more than 500 cities have implemented plastic bag bans. Without a federal policy, state and local governments are attempting to hold corporations accountable. Five states have passed laws requiring companies that produce plastic packaging to pay for the cost of recycling it. Several states and cities have sued companies including PepsiCo, Coca-Cola, and the kitchen goods company Reynolds for plastic pollution. They allege that the companies mislead consumers about the recyclability of items including beverage bottles and plastic bags. Many of these lawsuits are still ongoing, but results have so far been mixed. A judge dismissed New York State’s lawsuit against PepsiCo for plastic pollution. Meanwhile Minnesota received a settlement from Reynolds to help pay for plastic cleanup efforts.

And, experts say, individuals can still make a difference. Using less single-use plastic can help reduce your exposure to microplastics and prevent plastic pollution before it starts. Participating in cleanups helps remove plastic waste that would otherwise degrade into microplastics.

For his part, Cash, the teen environmentalist, has started setting up recycling bins across several Southern states where fishermen can dispose of their plastic fishing lines.

“If we can reduce single-use plastics, our planet would be a whole lot better,” he says. When it comes to fighting microplastics, “every little bit helps.” 

And, experts say, individuals can still make a difference. People using less single-use plastic can help reduce exposure to microplastics and prevent plastic pollution before it starts. Participating in cleanups helps remove plastic waste that would otherwise degrade into microplastics.

For his part, Cash has started setting up recycling bins across several Southern states where fishermen can dispose of their plastic fishing lines.

“If we can reduce single-use plastics, our planet would be a whole lot better,” he says. When it comes to fighting microplastics, “every little bit helps.”

With reporting by Nina Agrawal of The New York Times.

With reporting by Nina Agrawal of The New York Times.