No one yet knows the threat plastic pollution poses to human health, but the recent realization that we’re drinking invisible pieces of plastic along with our water has many people understandably worried. To help prevent micro- and nanoplastics from entering our bodies and brains, researchers at the University of Missouri have developed a potentially sustainable and safe way to rid water of microscopic contaminants.

Using natural liquid ingredients with low toxicity, the team showed that they were able to remove about 98 percent of the nanoscopic polystyrene beads from fresh and salt water. The solvent the researchers created floats on the surface of the water, similar to oil. But a quick stir and voila — the liquid picks up microscopic plastics in the water and floats them to the surface.

Researchers at the University of Missouri discovered that they could remove nearly all of the nanoplastic beads from contaminated water samples by sucking the top layer of the liquid with a pipette.

In salt water, the method removed 99.8% of all polystyrene contaminants.

Mizzou researchers say the proof of concept demonstrates a cost-effective and potentially “sustainable solution to the nanoplastics problem.” In further research, the technique could even be useful in permanently cleaning water from other contaminants, such as chemicals.

Previous studies have shown that tap and bottled water contain large numbers of microscopic pieces of plastic, particularly nanoplastics that are smaller than a micrometer in size. In fact, some estimates suggest that there are an average of 240,000 nanoplastic particles in every liter of bottled water.

These non-biodegradable materials are sometimes specially manufactured, and sometimes made from broken down microplastics. They can easily seep into natural ecosystems through rivers or drainage networks, tire wear, agricultural runoff, or sewage treatment schemes. Today, nanoplastics are found in water bodies around the world, including in remote locations such as the deep sea, the Arctic, and mountain lakes.

“Nanoplastics can disrupt aquatic ecosystems and enter the food chain, posing risks to both wildlife and humans,” says Piyuni Ishtavira, a chemist at Mizzou who led the research.

In addition, harmful chemicals such as heavy metals or flame retardants can also adhere to the surface of nanoplastics and interact with biological membranes. It is not easy to remove such small pollutants from the environment.

Recently, researchers in China found that boiling tap water can remove up to 90 percent of nano- and microplastics. This may be a simple way to remove contaminants from drinking water, but it’s not useful for large bodies of water that may be contaminated. A new technique from Mizzou could tackle nanoplastic pollution in a much more scalable way.

“Our strategy uses a small amount of designer solvent to adsorb plastic particles from a large amount of water,” explains chemist Gary Baker.

“Currently, the strength of these solvents is not sufficiently investigated. In future studies, we aim to determine the maximum solvent strength. We will also investigate methods to recycle the solvents and allow them to be reused if necessary.” The study was published in: ACS Applied Engineering Materials.