Water bottle brands often advertise their water as pure and pristine, derived from natural springs or other remote sources.

Scores of analyses have shown that most bottled water is no different than tap water and a new study conducted by scientists for Orb Media has found that bottled water actually contains more microplastic particles than what’s available in most people’s homes.

After analyzing 250 bottles from 11 brands purchased from nine countries, the team found that 93% of bottled water contains microplastics, particles too small to see with the naked eye but potentially hazardous to human health, according to the United Nations Food and Agriculture Organization, because plastic becomes a “magnet for pollutants” when in the water.

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The European Food Safety Authority has argued that most microplastics are excreted by the body, according to CBC Canada.

The study builds on an earlier analysis by Orb Media that found that the vast majority of tap water in the world contains microplastics.

This time around, Orb studied water from companies such as Nestle Pure Life, Aquafina, Dasani, Evian, and San Pellegrino.

They found that there were roughly 10.4 measureable particles of plastic per liter, and the real number could be higher, because smaller particles were unable to be verified.

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Even still, this is double the amount of microplastics found in the tap water from their previous analysis

“Some of the bottles we tested contained so many particles that we asked a former astrophysicist to use his experience counting stars in the heavens to help us tally these fluorescing constellations,” Christopher Tyree and Dan Morrison wrote for Orb Media.

“Sizes ranged from the width of a human hair down to the size of a red blood cell,” they added. “Some bottles had thousands. A few effectively had no plastic at all. One bottle had a concentration of more than 10,000 particles per liter.”

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Beverage brands disputed the findings when reached out to by CBC Canada.

“The science on microplastics and microfibres is nascent and an emerging field,” The American Beverage Association, which represents many of the biggest brands across North America, including Nestle, Evian, Dasani and Aquafina, told CBC.

“We stand by the safety of our bottled water products and we are interested in contributing to serious scientific research that will ... help us all understand the scope, impact and appropriate next steps,” the group added.

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Orb scientists used a method called Nile Red fluorescent tagging to identify the particles. When the dye is added to the water, it binds to and illuminates plastic, and then scientists can view the water under a microscope to count the particles, according to CBC.

In a circular sort of way, all the plastic produced and discarded in the world is finding its way back into the lives of humans.

Humans have created 8.3 billion metric tons of plastic since 1950, a weight equivalent to 1 billion elephants.

More than 75% of this plastic has been thrown away, left to disintegrate throughout the global environment. Each year, an estimated 8 million metric tons of plastic enter the oceans, which is like emptying a garbage truck of plastic into an ocean every minute.

As plastic breaks down into microplastics, it tends to blanket the sea floors, where it can disrupt bottom-feeding ecosystems.

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It also ends up in drinking water supplies, where it has largely unknown effects on the human body, according to the team at Orb Media.

“We don’t know what the [health] impact is and for that reason we should follow the precautionary principle and put enough effort into it now, immediately, so we can find out what the real risks are,” Dr. Anne Marie Mahon at the Galway-Mayo Institute of Technology, who conducted the research, told the Guardian.

“Once they are in the nanometre range they can really penetrate a cell and that means they can penetrate organs, and that would be worrying,” she added.  

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This latest study is another strike against the bottled water industry, which has grown to $147 billion annually.

Every minute of every day, a million bottles of water are consumed around the world and this number is rising exponentially, potentially reaching half a trillion annually by 2021.

The vast majority of these bottles aren’t recycled. Instead, they enter ecosystems, breaking down into microplastics, and ultimately adding to the problem of plastic in drinking water.

Global Citizen campaigns to reduce plastic production and consumption and you can take action on this issue here .