Bottled water, marketed as the essence of purity, is the fastest-growing beverage market in the world, valued at $147 billion per year.
But new research by Orb Media, a nonprofit media collective based in Washington, D.C., shows that a single bottle can hold dozens or possibly even thousands of microscopic plastic particles.
The world’s leading brands of bottled water are contaminated with tiny plastic particles that are likely seeping in during the packaging process, according to a major study across nine countries published Wednesday.
“Widespread contamination” with plastic was found in the study, led by microplastic researcher Sherri Mason of the State University of New York at Fredonia, according to a summary released by Orb Media.
Bottled water evokes safety and convenience in a world full of real and perceived threats to personal and public health.
Packaged drinking water is a lifeline for many of the 2.1 billion people worldwide who lack access to safe tap water. The danger is clear: Some 4,000 children die every day from water-borne diseases, according to the World Health Organization.
Humans need approximately two liters of fluids a day to stay hydrated and healthy—even more in hot and arid regions.
Orb’s findings suggest that a person who drinks a liter of bottled water a day might be consuming tens of thousands of microplastic particles each year.
Tests on more than 250 bottles from 11 brands reveal contamination with plastic including polypropylene, nylon, and polyethylene terephthalate (PET).
For plastic particles in the 100 micron, or 0.10 millimeter size range, tests conducted for Orb at the State University of New York revealed a global average of 10.4 plastic particles per liter. These particles were confirmed as plastic using an industry standard infrared microscope.
The tests also showed a much greater number of even smaller particles that researchers said are also likely plastic. The global average for these particles was 314.6 per liter.
Researchers tested 250 bottles of water in Brazil, China, India, Indonesia, Kenya, Lebanon, Mexico, Thailand, and the United States.
Plastic was identified in 93 percent of the samples, which included major name brands such as Aqua, Aquafina, Dasani, Evian, Nestle Pure Life, and San Pellegrino.
The plastic debris included polypropylene, nylon, and polyethylene terephthalate (PET), which is used to make bottle caps.
“In this study, 65 percent of the particles we found were actually fragments and not fibers,” Mason told Agence France-Presse (AFP).
“I think it is coming through the process of bottling the water. I think that most of the plastic that we are seeing is coming from the bottle itself, it is coming from the cap, it is coming from the industrial process of bottling the water.”
Particle concentration ranged from “zero to more than 10,000 likely plastic particles in a single bottle,” said the report.
On average, plastic particles in the 100 micron (0.10 millimeter) size range — considered “microplastics,” — were found at an average rate of 10.4 plastic particles per liter. Sizes ranged from the width of a human hair down to the size of a red blood cell. Mason’s tests were able to record microplastic particles as small as 6.5 microns, or 0.0065 millimeters.
Even smaller particles were more common — averaging about 325 per liter.
Other brands that were found to contain plastic contaminated included Bisleri, Epura, Gerolsteiner, Minalba, and Wahaha.
Experts cautioned that the extent of the risk to human health posed by such contamination remains unclear.
“There are connections to increases in certain kinds of cancer to lower sperm count to increases in conditions like ADHD and autism,” said Mason.
“We know that they are connected to these synthetic chemicals in the environment and we know that plastics are providing kind of a means to get those chemicals into our bodies.”
Previous research by Orb Media has found plastic particles in tap water, too, but on a smaller scale.
“Tap water, by and large, is much safer than bottled water,” said Mason.
For microplastic debris around 100 microns in size, about the diameter of a human hair, bottled water samples contained nearly twice as many pieces of microplastic per liter (10.4) than the tap water samples (4.45).
When contacted by reporters, two leading brands confirmed their products contained microplastic, but they said Orb’s study significantly overstates the amount.
Bottled water manufacturers emphasized their products met all government requirements.
Gerolsteiner, a German bottler, said its tests “have come up with a significantly lower quantity of microparticles per liter,” than found in Orb’s study.
Nestle tested six bottles from three locations after an inquiry from Orb Media. Those tests, said Nestle Head of Quality Frederic de Bruyne, showed between zero and five plastic particles per liter.
None of the other bottlers agreed to make public results of their tests for plastic contamination.
“We stand by the safety of our bottled water products,” the American Beverage Association said in a statement.
Anca Paduraru, a food safety spokeswoman for the European Commission, said that while microplastic is not directly regulated in bottled water, “legislation makes clear there must be no contaminants.” The U.S. doesn’t have specific rules for microplastic in food and beverages.
The three-month study used a technique developed by the University of East Anglia’s School of Chemistry to “see” microplastic particles using a special dye, an infrared laser, and a blue light like those used by crime-scene investigators.
Under a laminar airflow hood that sucks dust and airborne particles up and away, each bottle was infused with a dye called Nile Red that binds to plastic polymer and makes plastic fluorescent when irradiated with blue light. The dyed water was then poured through a glass fiber filter.
When viewed through a microscope, under the blue light, with the aid of orange goggles, the residue from each bottle glowed with the flame-colored fluorescence of sometimes thousands of particles.
The study has not yet been peer reviewed.
Particles over approximately 100 microns were confirmed to be plastic by both Nile Red and Fourier-Transform Infrared Spectrometry (FTIR). Because particles between 6.5 and 100 microns were not analyzed by FTIR, Mason left open the possibility that their number could include other, unknown, contaminants in addition to plastic, though rationally expected to be plastic. As with all science, future methods may allow for even more accurate identification of the tiny particles.
According to existing scientific research, the plastic particles you consume in food or drinks might interact with your body in a number of different ways.
As many as 90 percent of microplastic particles consumed might pass through the gut without leaving an impression, according to a 2016 report on plastic in seafood by the European Food Safety Authority.
What about the remaining ten percent?
Some particles might lodge in the intestinal wall. Others might be taken up by intestinal tissue to travel through the body’s lymphatic system. Particles around 110 microns in size (0.11 millimeters) can be taken into the body’s hepatic portal vein, which carries blood from the intestines, gallbladder, pancreas and spleen to the liver.
Smaller debris, in the range of 20 microns (0.02 millimeters) has been shown to enter the bloodstream before it lodges in the kidneys and liver, according to a 2016 report by the UN’s Food and Agriculture Organization.
Ninety percent of the plastic particles we found in our bottled water test were between 100 and 6,5 microns—small enough, according to researchers, for some to cross the gut into your body.
But very little research has been done on how frequently this might occur, or the health burden it might represent—a knowledge gap that some researchers say is in itself reason for concern.
Fluorescing particles that were too small to be analyzed by FTIR should be called “probable microplastic,” said Andrew Mayes, senior lecturer in chemistry at the University of East Anglia, because “some of it might be another, unknown, substance to which Nile Red stain is adhering.” Mayes developed the Nile Red method for identifying microplastic.
Nestle’s de Bruyne noted that Mason’s tests did not include a step in which biological substances are removed from the sample. Therefore, he said, some of the fluorescing particles could be false positives – natural material that the Nile Red had also stained. He didn’t specify what that material would be.
Mason noted that the so-called “digestion step” is used on debris-filled samples from the ocean or the seashore, and wasn’t needed for bottled water.
“Certainly they are not suggesting that pure, filtered, pristine water is likely to have wood, algae, or chitin [prawn shells] in it?” she said.
Some researchers say consuming microplastics in food and water might not be a serious issue.
“Based on what we know so far about the toxicity of microplastics—and our knowledge is very limited on that—I would say that there is little health concern, as far as we know,” says Martin Wagner, a toxicologist at the Norwegian University of Science and Technology. “I mean, that’s quite logical because I believe that our body is very well-adapted in dealing with those non-digestible particles.”
The 2016 evaluation by the European Union estimated that for microplastics consumed with shellfish, “only the smallest fraction may penetrate deeply into organs,” and that our exposure to toxins through this contact is low.
But according to Jane Muncke, managing director and chief scientist at the Food Packaging Forum, a Zurich-based research organization, those estimates are largely based on scientific models, and not laboratory studies.
Orb’s bottled water findings are “a very illuminative example of how intimate our contact with plastic is,” Wagner says.