plastics: Planetary Scale

By Petr Svab

Our world is getting polluted with plastics on a planetary scale. We can’t see much of it, but we’re starting to feel it. And it’s getting worse.

The plastic bottle tossed by the roadside and the endless trash heaps in thirdworld countries are just the beginning. As the trash ages, it breaks down into increasingly smaller pieces, until it can’t be seen with the naked eye anymore. At that point, however, the problems have barely begun.

These tiny pieces of plastic, called microplastics, have permeated everything, scientists have found in recent years. They can be as large as 5 millimeters and as small as 100 microns—about as thin as a human hair—or even smaller, at which point they’re sometimes referred to as nanoplastics.

Microplastics have been found in the most remote corners of the world.

“It doesn’t matter where we look—we find microplastics. In the environment, it could be at the bottom of the Mariana Trench, it could be the top of Mount Everest, and everywhere in between,” said Sherri “Sam” Mason, an associate professor at Penn State–Behrend who is an expert on microplastic pollution.

“As a consequence of it being everywhere in the environment, it’s everywhere within living organisms.”

Microplastics have been found in the animals we eat, in the water we drink, and in the air we breathe. It’s in our blood and in our organ tissues, even the deepest tissue of our lungs.

“We have a tendency to have this illusion that our skin separates us from the environment, but it is an illusion,” Mason said.

Children nowadays are being born with microplastics already in their bodies.

Plastic particles have been found on both sides of the placental boundary, meaning it’s seeping from the mother’s body into the unborn child.

The repercussions of such pollution are largely unknown. Getting definitive answers has proven immensely difficult. What research has been done, however, indicates the effects are negative.

“With regard to the human health impacts of it, perhaps unsurprisingly, none of them are good,” Mason said.

There are many ways to address the issue, but it isn’t clear whether a definitive solution is practically achievable. The pollution can be greatly reduced by ditching single-use plastic packaging and reforming the fashion industry. However, that still leaves a massive amount of plastic entering the environment, not to mention the substantial pollution there already is.

So far, research has largely focused on gauging the scale of the issue. It wasn’t until 2018, for example, that a paper was published at least somewhat accurately estimating how much plastic is floating in the Great Pacific Garbage Patch—the largest of several massive accumulations of plastic trash in the oceans. Even then, the estimate ranged from 45,000 to 129,000 metric tons.

Worldwide, some 7 billion metric tons of plastic trash are estimated to be in the environment, in landfills, oceans, and dumps, as well as just strewn around. That amount is expected to grow to 12 billion by 2050.

Research already has found that small pieces of plastic are a problem for fish and birds who mistake them for food. The plastic sits in their stomachs, making them feel full even though they may be malnourished. That, in turn, affects their growth and ability to procreate.

What the more microscopic plastic particles may do to the bodies of animals—or humans for that matter—is mostly unknown and may to a large degree remain so.

One of the problems is isolating the effect of plastics from all the other factors messing with human health.

“Some of the impacts are not acute,” said Marcus Eriksen, co-founder and researcher at 5 Gyres, an environmental group that aims to reduce plastic pollution. “If you have a liver packed full of nanoplastics or it’s in your placenta, how do you correlate that to harm?”

He cautioned that “in many cases, we’re not going to get clear-cut evidence because of the complexity of trying to establish a cause-effect relationship.”

One of the most established ways to discover the health effects of a substance is through placebo-controlled clinical trials—preferably long-term. But that’s particularly difficult in this case. Microplastics are so pervasive that there may be nobody left to form a control group.

“We’re all exposed. Who’s not?” Eriksen said.

Health impacts can be studied to some extent through animal experiments. It’s also possible to use artificial human tissue grown from stem cells.

“It’s expensive and time-consuming,” he said.

It’s easier to look at the effects of chemicals added to the plastics, such as flame retardants in solid plastics or water repellents in fabrics.

“We know more about the chemicals than we do the plastics, the material itself,” Mason stated, adding that “there are more than 10,000 chemicals that are used in the manufacturing of plastics, and many of these we already know have human health impacts.”

Moreover, microplastic can act as a “temporary sponge,” absorbing chemicals from the environment and releasing them later inside an organism, said Lisa Erdle, director of Science & Innovation at 5 Gyres.

Some chemicals that are added to plastics can cause cancer or harm fertility, according to Mason. As for the