Tests on some of the world’s most popular water brands have found that almost all of them contain tiny particles of plastic.
Analysis of 259 bottles of water, which were produced by 11 brands and bought in nine different countries, revealed that micro-plastics were present in 93% of the samples.
The study, commissioned by US journalism project Orb Media, found an average of 325 plastic particles per litre of water sold.
However, some bottles had a concentration of more than 10,000 micro-plastic particles per litre, with some pieces as large as the width of a human hair.
Only 17 of the 259 bottles analysed by scientists at the State University of New York in Fredonia were completely free of plastic contamination.
It is not yet clear whether ingesting the plastics is harmful to human health, but the World Health Organisation on Thursday announced it would conduct a review into the potential risks.
The particles were detected using Nile Red dye, which binds to plastic polymer.
While the study has not been peer-reviewed, University of East Anglia chemistry lecturer Andrew Mayes, who developed the Nile Red method, said the findings were substantial.
“I’ve looked in some detail at the finer points of the way the work was done, and I’m satisfied that it has been applied carefully and appropriately, in a way that I would have done it in my lab,” he said.
As part of the tests, Orb Media analysed water from US, China, Brazil, India, Indonesia, Mexico, Lebanon, Kenya and Thailand.
The brands tested as part of the experiment included:
- Nestle Pure Life
- San Pellegrino
Sherri Mason, a professor of chemistry at East Anglia university, told the BBC: “It’s not about pointing fingers at particular brands; it’s really showing that this is everywhere, that plastic has become such a pervasive material in our society, and it’s pervading water - all of these products that we consume at a very basic level.”
Both Gerolsteiner, a German water brand, and Nestle, have questioned the results of the Orb Media report.
While Gerolsteiner said its tests “have come up with a significantly lower quantity of micro-particles per litre,” than found in the study, Nestle said its own tests showed between zero and five plastic particles per litre of its water.