Massive amounts of tiny plastics found in bottled drinking water, study finds

Drinking more water every day is a healthy habit, but a new study has raised concerns about the container you should sip from.

Researchers from Columbia University and Rutgers University published the study Monday in the Proceedings of the National Academy of Sciences, which reveals an average of 240,000 detachable plastic fragments were found in a standard liter of bottled water.

Although the tiny "nanoplastics," which are smaller than one micrometer in size – less than one-seventieth the width of a human hair – may seem too small to be an issue, the data showed a large jump in concentrations found in bottled water.

Concentrations of micro-nano plastics found in testing were estimated to be 240,000 particles on average per liter of bottled water, "about 90% of which are nanoplastics," researchers wrote in the paper, after testing three unidentified brands of bottled water.

"This is orders of magnitude more than the microplastic abundance reported previously in bottled water," the paper notes.

"Individual particles for all seven plastic polymers from the library were identified, enabling statistical analysis of plastic particles with sizes down to 100 to 200 [nanometers]," the researchers said.

The International Bottled Water Association (IBWA) responded to the study, saying in part that there is "both a lack of standardized methods and no scientific consensus on the potential health impacts of nano- and microplastic particles," and adding that "media reports about these particles in drinking water do nothing more than unnecessarily scare consumers."

The IBWA also noted that the organization had "very limited notice and time to review this new study closely" and so "cannot provide a detailed response at this time."

For years, scientists have looked for microplastics, which can measure anywhere from one micrometer to half a centimeter in size. But identifying and analyzing nanoplastics, which are far smaller, presented a greater challenge. In response, researchers in the new study developed a "hyperspectral stimulated Raman scattering (SRS) imaging platform with an automated plastic identification algorithm" – essentially, using laser technology combined with computer analysis and machine learning – to enable identification and analysis of particles of plastics "at the single-particle level," according to the report.

Pieces of tiny plastics have previously been found in oceans, beaches and even tap water.

Phoebe Stapleton, a professor of pharmacology and toxicology at Rutgers University and co-author of the new study, said that scientists have known nanoplastics were in water, but explained, "if you can't quantify them or can't make a visual of them, it's hard to believe that they're actually there."

The new findings can help further study and identify the extent that nanoplastic consumption by humans may pose a health threat.

In 2022, the World Health Organization said there wasn't enough evidence "for reliable characterization and qualification of the risks to human health" adding the need for further research.

Although microplastics have been discovered in people's lungs, blood and excrement, scientists have said evidence that the particles may be harmful to human health has so far been inconclusive.