Where does plastic go when we’re done with it?

Human-made plastic materials have become so essential that it can be hard to grasp that they barely existed a century ago. At my desk, I’m typing on a plastic keyboard, scrolling a plastic mouse, picking up a plastic pen, tapping on a plastic calculator. Day after day, more plastic enters my life, whether it’s a shampoo bottle, a plastic clamshell of grapes or new running shoes.

The invention of synthetic plastics in the early 1900s was a triumph of innovation, with chemists realizing they could orchestrate molecular structures to create materials that are lighter, stronger, brighter, cheaper, more flexible and more durable.

During World War II, nylon and other plastics became essential to the war effort. When the war ended, the nascent plastics industry focused on making products for everyday life. That’s a history we explored last year as part of our Century of Science project (SN: 1/29/22, p. 16). You can read more on the rise of plastics and other innovations at Century of Science.

But the ubiquity of plastic has become a curse, with discarded objects clogging waterways and landfills. And when plastic does finally fall apart, minute particles disperse in the environment. We’ve known for years that microplastics have permeated the oceans (SN: 2/20/16, p. 20). In this issue, we report on research confirming that microplastics are also accumulating in our bodies. Plastic particles have been found in human blood, in body tissues and in breast milk.

Talk about environmental contamination hitting close to home. As independent journalist Anne Pinto-Rodrigues reports, microplastics probably enter the human body through the food we eat, the water we drink and even the air we breathe. Though consuming microplastics along with lunch is creepy enough, the notion that we might be inhaling invisible bits with each breath feels much more disturbing.

Researchers have only recently begun quantifying the abundance of microplastics in the air, so it’s not yet clear where people face the most exposure, whether at home, at work, on the road or somewhere else. Also unclear is what impact, if any, microplastics have on human health. Studies are just getting started to find the answers to these fundamental questions, and getting actionable data will take time.

I’m sure many of the pioneering chemists of a century ago didn’t think about the ultimate fate of the miracle materials they invented, nor of potential long-term impacts on health and the environment. Science abounds with examples of unintended consequences. The discovery of radioactive elements led to life-saving medical treatments and nuclear power, but also to nuclear weapons and disasters like the Chernobyl power plant meltdown.

Microplastics are an unintended consequence that we can’t put back into the Tupperware. Merely switching from plastic to paper bags won’t fix this problem. Science now needs to determine the extent of the threat microplastics might pose and invent new ways to protect against any harms.

Nancy Shute is editor in chief of Science News Media Group. Previously, she was an editor at NPR and US News & World Report, and a contributor to National Geographic and Scientific American. She is a past president of the National Association of Science Writers.